Charles Darwin's Shorter Publications, 1829-1883

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C H A R L E S D A RW I N ’ S S H O RT E R P U B L I C AT I O N S , 1 8 2 9 – 1 8 8 3 Charles Darwin’s words first appeared in print when he was a student at Christ’s College, Cambridge, in 1829, and in almost every subsequent year of his life he published essays, articles, letters to editors, or other brief works. These shorter publications contain a wealth of valuable material. They represent an important part of the Darwin visible to the Victorian public. Alongside his ever-present sense of humour, they reveal an even wider variety of his scientific interests and abilities, which continued to his final days. This book brings together all the known shorter publications and printed items Darwin wrote during his lifetime, including his first and last publications, and the first publication, with A. R. Wallace, of the theory of evolution by natural selection. With over 70 newly discovered items, the book is fully edited and annotated, and contains original illustrations and a comprehensive bibliography. J o h n v a n W y h e is a historian of science based at the University of Cambridge. He is co-editing Darwin’s Beagle notebooks, also with Cambridge University Press. In 2002 he launched Darwin Online, the aim of which is to make freely available online all of Darwin’s publications, unpublished manuscripts and associated materials. Darwin Online is the largest publication on Darwin ever created and is used by millions of readers around the world. Van Wyhe lectures internationally, and appears frequently on TV, radio and in the press, to discuss the life and work of Darwin.

CHARLES DARWIN’S SHORTER PUBLICATIONS 1829–1883 Edited by J O H N VA N W Y H E Christ’s College, Cambridge

CAMBRIDGE UNIVERSITY PRESS

Cambridge, New York, Melbourne, Madrid, Cape Town, Singapore, São Paulo Cambridge University Press The Edinburgh Building, Cambridge CB2 8RU, UK Published in the United States of America by Cambridge University Press, New York www.cambridge.org Information on this title: www.cambridge.org/9780521888097 © J. van Wyhe 2009 This publication is in copyright. Subject to statutory exception and to the provision of relevant collective licensing agreements, no reproduction of any part may take place without the written permission of Cambridge University Press. First published in print format 2009

ISBN-13

978-0-511-53448-5

eBook (NetLibrary)

ISBN-13

978-0-521-88809-7

hardback

Cambridge University Press has no responsibility for the persistence or accuracy of urls for external or third-party internet websites referred to in this publication, and does not guarantee that any content on such websites is, or will remain, accurate or appropriate.

Contents

Foreword by Janet Browne and Jim Secord Introduction Acknowledgements

page xv xix xxiv

C H A R L E S D A RW I N ’S S H O RT E R P U B L I C ATI O N S 1 8 2 9– 18 8 3 1829–1832 [Records of captured insects]. F1968

1

[Extracts from letters addressed to Professor Henslow]. F1

2

1835 1836 A letter, containing remarks on the moral state of Tahiti, New Zealand, &c. F1640

15

[Notes on Rhea americana and Rhea darwinii]. F1643 [Remarks upon the habits of the genera Geospiza, Camarhynchus, Cactornis and Certhidea of Gould]. F1644 Observations of proofs of recent elevation on the coast of Chili, made during the survey of His Majesty’s Ship Beagle commanded by Capt. FitzRoy R. N. F1645 A sketch of the deposits containing extinct Mammalia in the neighbourhood of the Plata. F1646 On certain areas of elevation and subsidence in the Pacific and Indian oceans, as deduced from the study of coral formations. F1647 [Note on an Australian insect.] F2015

31

1837

32

32 35 37 39

1838 On the connexion of certain volcanic phænomena, and on the formation of mountain-chains and volcanos, as the effects of continental elevations. F1649 [Notes on Cocos-Keeling Island plants]. F1959 Copy of a memorial presented to the Chancellor of the Exchequer, recommending the purchase of fossil remains for the British Museum. F1944 On the formation of mould. F1648

40 45 46 48 v

Contents

vi

1839 Observations on the parallel roads of Glen Roy, and of other parts of Lochaber in Scotland, with an attempt to prove that they are of marine origin. F1653 Questions about the breeding of animals. F262 Note on a rock seen on an iceberg in 61° south latitude. F1652

50 91 95

1840 On the connexion of certain volcanic phenomena in South America; and on the formation of mountain chains and volcanos, as the effect of the same powers by which continents are elevated. F1656 On the formation of mould. F1655 [Notes on Chilean beetles.] F2010

97 124 128

1841 Queries respecting the human race, to be addressed to travellers and others. F1975* [Notes on South American beetles.] F2016 On the distribution of erratic boulders and on the contemporaneous unstratified deposits of South America. F1657 [Notes on South American spiders.] F2011 Humble-bees. F1658 On a remarkable bar of sandstone off Pernambuco, on the coast of Brazil. F266 [Note on a ground-beetle found off the Straits of Magellan.] F2012

128 128

[Notes on South American beetles.] F2013 [Note on a mushroom from Maldonado.] F2014 Notes on the effects produced by the ancient glaciers of Caernarvonshire, and on the boulders transported by floating ice. F1660 On the distribution of the erratic boulders and on the contemporaneous unstratified deposits of South America. F1661 Report of a Committee appointed “to consider the rules by which the nomenclature of Zoology may be established on a uniform and permanent basis.” F1661a*

140 140

128 133 134 137 140

1842

140 147 162

1843 Remarks on the preceding paper in a letter from Charles Darwin, Esq. to Mr Maclaren. F1662 Double flowers—their origin. F1663

162 165

Observations on the structure and propagation of the genus Sagitta. F1664 [Extracts from letters on guanacos]. F1833 On the origin of mould. F1665 Manures and steeping seed. F1666 Variegated leaves. F1667 What is the action of common salt on carbonate of lime? F1668 Mr. Darwin’s Memorandum [on rust in wheat]. F1668a

167 172 173 174 175 176 176

1844

*

Items omitted for lack of space are indicated with*

Contents An account of some seeds buried in a sand-pit which germinated. F1918 Brief descriptions of several terrestrial planariæ, and of some remarkable marine species, with an account of their habits. F1669

vii

177 179

1845 Extracts from letters to the General Secretary, on the analogy of the structure of some volcanic rocks with that of glaciers. F1670 [Letter on Patagonian stone]. F1989 On an edible fungus from Tierra del Fuego. F1671 Additional testimonials submitted to the Council of University College, London, by Edward William Brayley. F324a Testimonials in favour of Joseph Dalton Hooker. F2030

188 188 189 191 191

1846 [Note on sandstone and query on coral reefs]. F1915 An account of the fine dust which often falls on vessels in the Atlantic ocean. F1672 On the geology of the Falkland Islands. F1674

192 192 196

[Review of] A natural history of the Mammalia. F1675 Salt. F1676 Copy of Memorial to the First Lord of the Treasury, respecting the Management of the British Museum. F1831

204 207

On the transportal of erratic boulders from a lower to a higher level. F1677

209

Geology. In A manual of scientific enquiry. F325 On the use of the microscope on board ship. In A manual of scientific enquiry. F1822 [Letter on floating ice]. F1816

217 235 241

On British fossil Lepadidæ. F1679

241

[Notes on a Galapagos lichen]. F2017 Testimonials for Thomas H. Huxley. F344

242 242

Bucket ropes for wells. F1680 [Letter on the bookselling question]. F1912

242 243

[Description of Patagonian fossil beds]. F1820 Tanks and hose. F1807

243 243

On the power of icebergs to make rectilinear uniformly-directed grooves across a submarine undulatory surface. F1681 Does sea-water kill seeds? F1682 Does sea-water kill seeds? F1683 Lizard’s eggs. F1808 Nectar-secreting organs of plants. F1684

244 246 247 249 250

1847

207

1848 1849

1850 1851

1852

1853

1855

viii

Contents Shell rain in the Isle of Wight. F1685 Vitality of seeds. F1686 Effect of salt-water on the germination of seeds. F1687 Effect of salt-water on the germination of seeds. F1688 Longevity of seeds. F1689 Seedling fruit trees. F1690

250 251 252 253 254 254

[Typical list of cirripedia]. F1977 Cross breeding. F1691 [Announcement of the award of a Royal Medal to John Richardson]. F1936

255 256 256

Hybrid Dianths. F1693 On the action of sea-water on the germination of seeds. F1694 Mouse-coloured breed of ponies. F1695 The subject of deep wells. F1696 Bees and the fertilisation of kidney beans. F1697 Productiveness of foreign seed. F1698

257 258 266 266 267 268

[Letter on zoological nomenclature]. F1983 Memorial on proposed severance from the British Museum of its natural history collections. F1942 On the agency of bees in the fertilisation of papilionaceous flowers, and on the crossing of kidney beans. F1701 [Memorial] Public natural history collections. F1702 [Contribution to the Field-Lane refuges]. F1935 On the tendency of species to form varieties; and on the perpetuation of varieties and species by natural means of selection. F350

269

[Letter on the collections of the British Museum]. F1934 Coleoptera at Down. F1703

296 297

Cross-bred plants. F1704 Natural selection. F1705 Intercourse between common and Ligurian bees. F1814 Fertilisation of British orchids by insect agency. F1706 Do the Tineina or other small moths suck flowers, and if so what flowers? F1708 Irritability of Drosera. F1813

297 299 299 300 302 303

Note on the achenia of Pumilio argyrolepis. F1709 Fertilisation of British orchids by insect agency. F1706 Dun horses. F1960 Influence of the form of the brain on the character of fowls. F1961 Phenomena in the cross-breeding of plants. F1713 On dun horses, and on the effect of crossing differently coloured breeds. F1962

303 305 306 306 307 308

1856

1857

1858

269 272 278 282 282

1859

1860

1861

Contents

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Cross-breeding in plants. Fertilisation of Leschenaultia formosa. F1714 Dun horses. F1963 Fertilisation of Vincas. F1836 Cause of the variation of flowers. F1715 Effects of different kinds of pollen. F1823 Parents of some gladioli. F1819 Orchids, Fertilization of. F1712 Vincas. F1716 Is the female bombus fertilised in the air? F1818

309 311 311 312 314 315 315 316 316

[Recollections of Professor Henslow]. F830 Do bees vary in different parts of Great Britain. F1716a Bees in Jamaica increase the size and substance of their cells. F1826 Bee-cells in Jamaica not larger than in England. F1824 On the three remarkable sexual forms of Catasetum tridentatum. F1718* Peas. F1719 On the two forms, or dimorphic condition, in the species of Primula. F1717* Cross-breeds of strawberries. F1720 Variations effected by cultivation. F1721 Penguin ducks. F1825

317 319 320 321 321 321 322 322 323 324

On the so-called “auditory-sac” of Cirripedes. F1722 Influence of pollen on the appearance of seed. F1828 Vindication of Gärtner—effect of crossing peas. F1727a On the existence of two forms, and on their reciprocal sexual relation, in several species of the genus Linum. F1723* Fertilisation of orchids. F1724a [Review of] Contributions to an insect fauna of the Amazon Valley. By Henry Walter Bates. F1725 The doctrine of heterogeny and modification of species. F1729 Origin of species. F1730 [Letter on yellow rain]. F1727 Appearance of a plant in a singular place. F1727b Vermin and traps. F1728 Lettre de M. Darwin à M. de Quatrefages. F1837 On the thickness of the Pampean formation, near Buenos Ayres. F1724

324 327 327

On the sexual relations of the three forms of Lythrum salicaria. F1731* Ancient gardening. F1732 [Letter to the Council of the Royal Horticultural Society]. F1910

345 346 346

On the movements and habits of climbing plants. F1733* Testimonials in favour of Mr. Adam White. F345b Note on Medicago lupulina. F1809

347 347 348

1862

1863

329 329 330 334 337 338 338 339 340 342

1864

1865

Contents

x

1866 Partial change of sex in unisexual flowers. F1735 [Note on the common broom, Cytisus scoparius]. F1737 Oxalis bowei. F1736 Cross-fertilising papilionaceous flowers. F1737a Feet of otter hounds. F1930

348 349 349 350 351

Queries about expression. F876 Cut or uncut. F1815 Fertilisation of Cypripediums. F1738 Hedgehogs. F1740

351 353 354 355

1867

1868 On the character and hybrid-like nature of the offspring from the illegitimate unions of dimorphic and trimorphic plants. F1742 [Inquiry about sex ratios in domestic animals]. F1743 On the specific difference between Primula veris, Brit. Fl. (var. officinalis, of Linn.), P. vulgaris, Brit. Fl. (var. acaulis, Linn.) and P. elatior, Jacq.; and on the hybrid nature of the common Oxlip. With supplementary remarks on naturally-produced Hybrids in the genus Verbascum. F1744* Undated [Printed acknowledgement of correspondence]. F1958

356 356

356 357

1869 The formation of mould by worms. F1745 Origin of species [On reproductive potential of elephants]. F1746 Origin of species [On reproductive potential of elephants]. F1747 Notes on the fertilization of orchids. F1748 [Extract of a letter on fertilisation of Vinca by insects]. F1971 The fertilisation of winter-flowering plants. F1748a Pangenesis.—Mr. Darwin’s reply to Professor Delpino. F1748b

357 358 359 360 360 361 361

[Letter on marine shells in the Amazon]. F1990 [Note on the age of certain birds]. F1991 [Note on Darwin’s papers to the Plinian Society 27 March 1827]. F1749 Memorial to the Right. Hon. the Chancellor of the Exchequer. F869 [Letter of apology regarding the honorary degree ceremony at Oxford]. F1940 Notes on the habits of the pampas woodpecker (Colaptes campestris). F1750

363 363 364 364

[Two letters to C. Boner]. F1950 Pangenesis. F1751 [Letter to C. L. Balch of the New York Liberal Club]. A letter from Mr. Darwin. F1981 A letter from Mr. Darwin [The Index]. F1753 A new view of Darwinism. F1754 Fertilisation of Leschenaultia. F1755

367 368

1870

365 365

1871

369 370 370 371

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1872 Mr. Ayrton and Dr. Hooker. F1937* Bree on Darwinism. F1756

373 373

Natural selection. F1758 Inherited instinct. F1757 Testimonials in favour of W. Boyd Dawkins. F1216 Perception in the lower animals. F1759 Origin of certain instincts. F1760 Instinct: Perception in ants. F1810 Habits of ants. F1761 On the males and complemental males of certain cirripedes, and on rudimentary structures. F1762 [Note on nematodes]. F1974

374 375 376 376 377 381 381

1873

382 386

1874 Memorial presented to the First Lord of the Treasury, respecting the National Herbaria. F1954 Recent researches on termites and honey-bees. F1768 Fertilisation of the Fumariaceæ. F1769 Flowers of the primrose destroyed by birds. F1770 Flowers of the primrose destroyed by birds. F1771 [Memoranda on Drosera filiformis]. F1932 [Irritability of Pinguicula]. F1767

386 388 389 390 391 393 394

[Memorial to A. H. Gordon, Governor of Mauritius, requesting the protection of the Giant Tortoise on Aldabra]. F2006 [Letter to Haeckel on the origins of Darwin’s theory of evolution]. F1916

394 396

1875

1876 [Letters to J. Torbitt on potato propagation]. F1978 [Evidence given to the Commission on the practice of subjecting live animals to experiments]. F1275 Cherry blossoms. F1772 Sexual selection in relation to monkeys. F1773

397

[Letter on Stock Dove]. F1951 Holly berries. F1774 [The scarcity of holly berries and bees]. F1775 To members of the Down Friendly Club. F1303 Fertilisation of plants. F1780 Testimonial to Mr. Darwin—Evolution in the Netherlands. F1776 Scrofula and in-breeding. F1972 [Memorial] Zoology of the ‘Challenger’ Expedition. F2003 Note to Mr. Francis Darwin’s paper. F1777

403 403 404 405 406 406 407 408 409

398 399 400

1877

xii

Contents A biographical sketch of an infant. F1779 [Memorial to Earl Carnarvon on the proposed South African Confederation by the Committee of the Aborigines Protection Society]. F1926 The contractile filaments of the teasel. F1778 Fritz Müller on flowers and insects. F1781 Growth under difficulties. F1782

409

[Report of conversation]. Mr. Darwin at Down. F1999 [Extracts of letters on potato cultivation]. F1979 Prefatory letter. In Kerner, Flowers and their unbidden guests. F1318 Transplantation of shells. F1783 [Memorial to the Vice-Chancellor respecting the Examination in Greek in the Previous Examination]. F1939

420 421 421 422

416 417 418 419

1878

423

1879 Fritz Müller on a frog having eggs on its back—on the abortion of the hairs on the legs of certain caddis-flies, &c. F1784 Rats and water-casks. F1785 [Extract from a letter to Grant Allen]. F2004 [Report of conversation]. Lettres de Londres: X. F2000

424 426 426 426

[Letter to Samuel Butler on Kosmos and Erasmus Darwin]. F1992 Darwin’s reply to a vegetarian. F1984 [Letter on purportedly carnivorous bees]. F1953 Fertility of hybrids from the common and Chinese goose. F1786 The sexual colours of certain butterflies. F1787 The Omori shell mounds. F1788 Encouragement of original research: the Darwin prize. F1993 Sir Wyville Thomson and natural selection. F1789 [Letter of thanks to the Yorkshire Naturalists’ Union]. F1969 Black sheep. F1790

427 428 428 429 430 432 433 433 434 434

[Letter on the expression of the eye]. F1994 [Extracts from two letters on the drift deposits near Southampton]. F1351 [Letter on subsidence in the Pacific]. F1952 Movements of plants. F1791 [Letter to Emily Talbot]. Social science.—Infant education. F1995 Mr. Darwin on vivisection. F1352 Mr. Darwin on vivisection. F1793 The movements of leaves. F1794 [Letter to G. E. Mengozzi on design in nature]. F1970 Inheritance. F1795 Rolleston memorial. F1957 Mr. Darwin on Dr. Hahn’s discovery of fossil organisms in meteorites. F1929

435 436 437 438 439 441 442 443 445 446 448 449

1880

1881

Contents

xiii

Mr. Darwin on mosquitoes. F1948 Leaves injured at night by free radiation. F1796 The parasitic habits of Molothrus. F1798 Mr. Charles Darwin and the defence of science. F1799

450 450 451 452

Prefatory notice. In Weismann, Studies in the theory of descent. F1414 The action of carbonate of ammonia on chlorophyll-bodies. F1801 The action of carbonate of ammonia on the roots of certain plants. F1800 On the dispersal of freshwater bivalves. F1802 Preliminary notice. In Van Dyck, On the modification of a race of Syrian street-dogs by means of sexual selection. F1803

452 453 470 486

Prefatory notice. In Müller, The fertilisation of flowers. F1432

490

1882

488

1883

Bibliography Index

493 516

Foreword

The significance of Charles Darwin as a maker of present times has never been more evident than in the bicentennial of his birth. On the Origin of Species, first published a century and a half ago and continuously in print ever since, transformed the centuries-old debate about the history and origins of living beings. That book, and his other volumes on evolution by natural selection, were highly significant contributions to the intellectual, biological and theological revolutions of nineteenth-century Britain. And Darwin also became one of the most famous scientists of his day, a Victorian celebrity whose work even in his own lifetime was regarded as a foundation stone for the modern world, not least for the manner in which his writings changed the way human beings thought about themselves and their own place in nature. There can be no doubt about the worldwide significance of his impact. Yet he was also a country gentleman pottering around his garden. He was an invalid plagued by mysterious disorders. He was a traveller, husband, father, friend, and employer, as well as a remarkable thinker. Above all else, however, Darwin was an investigative naturalist. He loved to explore the quietly complex phenomena of living organisms or ponder the effects of geological processes, either in the localities he knew best around his country home in Kent, or ranging widely through the books he read in the evenings. Small details caught his attention. Sometimes he would hurry out to his greenhouse to begin an experiment that might test a statement that had recently come to hand. Or he might turn to friends and relations for verification. Always, his mind was alert to the tiny fact, the unobserved point that might contribute to his larger insight into the living world. This trait was evident in Darwin’s character from very early on, and still charms readers today. Just before the Beagle voyage took place, his uncle Josiah Wedgwood called him ‘a man of enlarged curiosity’. The description fitted him well throughout a long and active life. This comprehensive collection of articles, essays, questions, comments, and printed notes by the great naturalist presents a remarkable record of Darwin’s ‘enlarged curiosity’. To be sure, Darwin published a number of lengthy books, which he viewed as the core of his literary output. Yet his shorter publications reflect many of the most significant aspects of his life’s work. Among them are some of the letters written during the Beagle voyage – issued by his mentor John Stevens Henslow as a pamphlet for private circulation – that gave the London scientific world a tantalizing glimpse of Darwin’s findings of fossil bones and hitherto unknown creatures. Upon his return, Darwin began immediately submitting his xv

xvi

Foreword

work to the scrutiny of scientific colleagues, publishing his work in the burgeoning range of monthly and quarterly scientific periodicals. These early articles announced his theory of the formation of coral reefs and made public his ambitious analyses of global uplift and subsidence. His first major paper, in the Royal Society’s Philosophical Transactions, was on the much-discussed Parallel Roads of Glen Roy in the Scottish Highlands, a series of linear terraces that had puzzled naturalists for decades. Although Darwin later regarded this paper as ‘great failure’, it reveals many aspects of his methods of theorizing during the most creative period of his life. Darwin continued to publish substantial essays and articles, often in later years as precursors to longer books. The most famous of these, also included here, is the joint presentation (with an essay by Alfred Russel Wallace) of the theory of natural selection delivered before the Linnean Society in 1858. The greatest revelation of this volume, however, is in bringing together all of Darwin’s known short notes, queries, commentaries, and other occasional contributions to Victorian periodicals, newspapers and other ephemeral publications. These range from incidental comments in Victorian gardening magazines to questionnaires issued to willing friends and relatives. They include notes on microscopes, hedgehogs, honeybees, dogs’ feet, lizard’s eggs, cherry blossoms, and an edible fungus found in Tierra del Fuego. Anyone interested in Darwin owes John van Wyhe a large debt of gratitude for providing authoritative texts of this diverse material. Building on and correcting the work of previous scholars, this volume contains some eighty items unknown or overlooked when Darwin’s papers were last brought together by Paul Barrett in 1977, including over thirty discovered by van Wyhe himself. It is remarkable, in any field, to have so much material for a major author made freshly available. In these occasional writings, it could be said, Darwin shows us himself. At one level, they display his mind at work. Here we can see the individual problems that preoccupied him, on the one hand ranging over an extraordinary variety of topics and on the other providing sustained evidence of genuine intellectual penetration. We can see Darwin catching hold of a problem and reformulating it in new ways, either as a question that might be answered by the observations of some other naturalist or presenting the results of some recent work that open up further questions for research. In a larger sense, these notes can also tell us about the making of a scientific fact – the processes of research and observation, the questions and experiments, the validation and authentication through further inquiry. Indeed, seeing Darwin’s smaller publications en masse in such a fashion opens the door for a re-evaluation of the way that science was made in the years before large laboratories existed. Darwin’s shorter publications show us the heart of the scientific process at a time that is often characterized as the starting point for its modern consolidation. At another level, too, these shorter publications are true to the man behind the theories. Much of the rationale in drawing these publications together is that they show how varied and regular a contributor Darwin was to Victorian periodicals. It is a revelation to see how persistently he used the format of minor publication to elicit comment and feedback, how he cultivated a wide range of contacts, many of whom he did not know except through the columns of natural history magazines. This again speaks to the way that natural history was pursued in Victorian Britain. Few such contributors to journals became as famous

Foreword

xvii

as Darwin. Many were academic naturalists, established experts, landowners, well-known animal or plant breeders, or knowledgeable amateurs who vigorously pursued topics of mutual concern in an increasingly wide variety of illustrated magazines, journals and popular books. Here Darwin comes among them as an equal, as a reader intrigued by bees’ combs, the tendrils on climbing plants, or the transmission of wing markings in domesticated pigeons. Here he could broadcast his inquiries to a community of knowledgeable experts. More than this, the geographical reach of the nineteenth-century natural history community was startlingly broad. The international scope of these shorter publications stretches beyond Britain to Europe and the wider world, for Darwin’s intentions were global in scale. He eagerly made use of the extended domain of British colonial institutional structures and sought out personal links in key locations. From the closely packed columns of popular natural history magazines to the short pamphlets that he had printed up at his own cost for circulation, Darwin appears as a regular and spirited contributor to Victorian natural history. All these features reveal him as the man we have always suspected, but never fully seen in print. Janet Browne Jim Secord

Introduction

Charles Robert Darwin (1809–1882), the great English naturalist and geologist, changed forever our understanding of the world and our place within it. Many of his contemporaries regarded him as the greatest living man of science of their own and perhaps of any age. Some used the word ‘revolution’ to describe the profound alteration they believed Darwin effected in scientific knowledge. He synthesized many of the already sophisticated sciences of his day from geology, palaeontology, zoology, embryology, physiology, taxonomy, anthropology, botany, psychology and more. After Darwin’s death countless obituaries and biographical accounts continued to laud him as the one figure who had solved the greatest puzzles of life on earth. Against this it seems hardly relevant that many of them did not, or did not fully, accept Darwin’s stress on natural selection as the primary mechanism for evolution or ‘descent with modification’. What Darwin did achieve was to convince the international scientific community and their descendants for the succeeding century and more that all the kinds of living things on earth are derived from common ancestors. The single branching genealogical tree of life is Darwin’s vision.1 This explanation unlocked the basic pattern of past and present life on earth, and was consistently attributed to Darwin. It took until the ‘new synthesis’ in the 1930s to fully seal the role of natural selection.2 Yet we must always strive to envisage Darwin not as a timeless ideal genius but as a real person living in his own time and context. This is all the more difficult because his world has largely vanished with the lapse of time. Sometimes particular facts can help to imaginatively reconstruct the richness of his world. Darwin was a wealthy and respected member of the nineteenth-century English gentry. He belonged to gentlemans’ clubs, scientific societies and was treasurer of the local village savings society. He read The Times, cheap romantic novels, especially if they had beautiful heroines and the works of George Eliot and Charles Dickens. He interacted with a wide range of his contemporaries from fellow Cambridge undergraduates (many of them noblemen), other elite men of science and their families, South American Indians, pigeon fanciers, as well as servants in the home, labourers in the field and local villagers and clergymen. He invested in the new railways and played with his children and dogs. He went for daily walks in the countryside near his rural home, Down House, in Downe, Kent, about fifteen miles from the centre of London. He corresponded with thousands of individuals about his scientific interests. Many of his letters appeared xix

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Introduction

in newspapers and magazines. Darwin was only one man amongst a large international scientific community. This meant that in addition to profiting from the reference works and publications of other naturalists, his science was also a dialogue with his peers. Darwin’s views are most widely known from his books. The Origin of Species is often referred to as one of the most important and famous books ever written. Similarly his Journal of Researches (now commonly known as Voyage of the Beagle) and Descent of Man are very well known. Darwin’s adult life revolved around a series of researches that culminated in scientific publications. He published sixteen books, or twenty depending on how we count them. All have been reprinted, some many times, and are still in print; consequently, they are widely available. Yet there were at least 244 unique shorter publications of Darwin’s writings during his lifetime. These are scattered amongst many now rare newspapers, magazines, journals, offprints and books and pamphlets by other authors. No library possesses all of them. This book brings these scattered productions of Darwin’s pen together between the covers of a single volume for the first time. It is impossible to understand Darwin’s life and work from his books alone. They are the milestones,3 but there is much valuable material in the stepping stones dotted between them. After his first words appeared in print as a student at Christ’s College, Cambridge, in 1829, more appeared in an essay, article, letter to an editor, or other brief publication every following year of his life except 1833–4 and 1854. The shorter publications represent an important part of the Darwin visible to the Victorian public. They reveal, if possible, an even wider variety of his scientific interests and abilities. They also reveal his ever present sense of humour. Darwin was not a frightened recluse, but a well-liked family man of independent means obsessed with scientific puzzles. The shorter publications show how his curiosity to understand the natural world continued to his final days. In his very last publications he cited the latest international scientific works of 1882. Contributions by Darwin appeared in dozens of periodicals, not just scientific journals but newspapers, gardening, horticultural and country sporting magazines. A basic analysis of the shorter publications shows an early mixture of geological and zoological publications until the mid-1850s. From the mid-1840s botanical items became more numerous although they are absent from the 1846–1854 barnacle research period. The zoological items appeared more or less continuously throughout his life. Many deal with Darwin’s interests in the natural means by which species may become distributed about the globe. Both before and after the publication of Origin of Species Darwin tended not to discuss the ultimate aims behind his queries. There are roughly 30 geological, 100 zoological and 100 botanical items. Another extremely loose category might be called social items such as the letter defending missionaries, signed memorials on the British Museum’s collections, domestic gardening issues, donations to charities and opposition to cruelty to animals. Later, after the Origin of Species and Descent of Man, items answering critics became more numerous. The second paragraph of Darwin’s 1863 letter in the respectable Athenaeum (p. 334 below) gives one of his best concise summaries of the evidence for his theory of evolution. The shorter publications are almost silent on politics and religion.

Introduction

xxi

The first collection of Darwin’s papers was published by Paul Barrett in 1977. Although it has performed valuable service for thirty years, a more complete collection is long overdue. Many new shorter publications have been discovered since 1977. The editors of the Correspondence have uncovered most of these and new items are still occasionally found. Thirty-three items were discovered during the preparation of this book and in the course of creating and editing The Complete Work of Charles Darwin Online (http://darwinonline.org.uk/) [hereafter Darwin Online] – some shortly before this volume went to press. With the increasing range of historical publications available electronically, many more previously unrecorded Darwin publications will no doubt be found. These can be added to Darwin Online if their discoverers will send me copies or references. Barrett’s Collected Papers included only 153 items and omitted parts of the original publications such as the exact titles, Darwin’s salutation, valediction and dates of letters. There were also several errors such as incorrect publication dates, missing words and incomplete bibliographical details. The present work brings together all known Darwin publications and shorter than booklength printed items during his lifetime, minus nine omitted for lack of space. The single item from 1883 is included because it is both short and Darwin intended it for publication. This volume therefore contains the majority of Darwin’s publications, in terms of number, including his first and his last publications. The year 2009, the 200th anniversary of Darwin’s birth and the 150th anniversary of the publication of the Origin of Species, seems an appropriate time to publish the shorter publications in print. These documents are all available in Darwin Online. There are a number of reasons to publish them as a book. Many people prefer to read and study a physical volume rather than reading from a screen or printouts. With an unforeseeable future of ever shifting technological landscapes before us, a printed volume remains reassuringly permanent. And print still reaches different audiences who cannot, or do not, use the internet. A publication, following the criteria of Darwin’s great bibliographer R. B. Freeman, is anything printed during his lifetime that was: written by Darwin, signed by Darwin, or a quotation of his unpublished words. Although a few items were privately printed, and therefore not technically published, they have traditionally been counted amongst Darwin’s publications and are also included here. Reprints, quotations from his published works and foreign translations are not included. Lack of space has forced me to omit a few of Darwin’s longer essays but in most cases these later appeared in some of his books and therefore may be treated differently. These, and several other associated passages such as lists of co-signatories on memorials signed by Darwin, or very lengthy items only signed by Darwin are omitted for lack of space. The omitted text amounts to 107 000 words. All omitted items are available on Darwin Online. The shorter publications included here total about 240 000 words, which, together with the notes and 11 000 word bibliography, are as much as could be included within a single volume. Barrett’s collection was largely un-annotated. This volume, for the first time, identifies, where possible, all persons and publications cited or mentioned by Darwin. Most of these

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have remained unidentified since Darwin’s day. Others remained elusive and as every editor knows there comes a time when further fruitless searching must be given up in the interest of completing the whole. The bibliography is therefore a supplement to works read and referred to by Darwin. Combined with the bibliographies of the Correspondence, Natural Selection and the Marginalia a complete bibliography of the works cited and used by Darwin is approached. Darwin’s shorter publications have been arranged chronologically according to their given publication dates. Items dated no more specifically than by year are listed at the beginning of that year. The omitted items are given a full reference at the appropriate point to avoid obscuring their place altogether.

Editorial policy I have endeavoured to reproduce the original documents faithfully. Spelling, punctuation, even apparent misprints have been preserved. Original editorial comments in Darwin’s publications are retained when space permits. The original pagination has been preserved between vertical lines, e.g. |195|. Darwin’s or original editorial notes are given as footnotes. New bibliographical references are cited in author–date format; complete references can be found in the bibliography. Multiple items by the same author in the same year are distinguished with the addition of letters, e.g. 1850a, 1850b, etc. Darwin’s publications are indicated in a different and somewhat unconventional, but hopefully more useful, system than a series of arbitrary abcs – which would have to be changed when any new interceding items are discovered. Instead Darwin’s shorter publications are cited as author–date followed by the Freeman or ‘F’ number (e.g. Darwin 1840, F1656) according to the standard bibliography begun by R. B. Freeman. These numbers are unique identifiers associated with each publication. The definitive edition of the bibliography of Darwin’s writings is published on Darwin Online. Freeman assigned new numbers in his second edition (1977). When preparing the new online edition based on his work I decided to freeze Freeman’s numbers which had stood for so long and which are so widely cited. Additions to the bibliography are assigned new numbers consecutively from F1806 onwards. The numbers, though often running continuously and chronologically, should be regarded as arbitrary. For items included in this book, the page number is provided in parentheses after the ‘F’ number. I have taken no notice of items at some point recorded as Darwin publications but which do not meet the above criteria. I have retained a few exceptions, as, for example, the report of Darwin’s remarks on Gould’s description of the Galapagos finches, which are brief and of particular significance.

Annotations Space restrictions permit only minimal notes. I have aimed at making the material as accessible as possible for a wide range of readers. New editorial notes are provided

Introduction

xxiii

as endnotes after each of Darwin’s shorter publications and in brackets when in Darwin’s footnotes. All persons mentioned have been identified, when possible, with a note at their first occurrence and only subsequently when clarity required. Surnames can be found at any time via the index. The notes are meant merely to identify the individual and therefore usually provide only dates and a statement of profession or activity and current role or office. Titles are ignored. The Correspondence biographical register, Freeman’s Companion or other reference works should be consulted for more detail. Throughout the notes the abbreviation ‘CD’ is used for Charles Robert Darwin, ‘DAR’ refers to the Darwin Archive at Cambridge University Library, ‘CCD’ refers to The Correspondence of Charles Darwin, and ‘DO’ refers to Darwin Online. I have followed the standard abbreviations of Darwin’s and other key works used by the Correspondence. These can been found in the bibliography alphabetically according to the abbreviated title, rather than by author name. Editorial comments in the texts are enclosed in square brackets. Any original square brackets have been changed to parentheses. Publications mentioned or cited by Darwin are identified, when possible, at their first occurrence and only subsequently if clarity seemed to require it. The aim was to make the original text intelligible and useful but not to note every relevant secondary source. In addition to the lack of space this would also lead to the volume perhaps becoming prematurely dated. I have also noted items that were noted by Barrett 1977, even when such points are not otherwise noted in this volume, for readers who do not possess both works. Items only signed by Darwin are more sparsely annotated. Many of the published letters in this volume have already been masterfully edited and published in the Correspondence. It would be futile to attempt to improve on their work, even though such printed items also have a place in this volume. In such cases the first endnote includes a reference to the item’s place in the Correspondence which in most instances provides more detailed annotations than have been attempted here. No doubt some mistakes and inconsistencies remain. The task has been, at times, overwhelming and I am keenly aware of my inadequacies. It ought, perhaps, to have been undertaken by a team of researchers. I would be grateful to be informed of mistakes and any unidentified Darwin publications fitting the above criteria.

1 2 3

See Darwin 1863, F1730 (p. 506) and Hodge 2005. Mayr 1982. Autobiography, p. 136.

Acknowledgements

In preparing this volume I have, to paraphrase Darwin, incurred a heavy, but pleasant load of gratitude to many individuals and institutions. It is a great pleasure to thank them here. The Arts and Humanities Research Council and the Centre for Research in the Arts, Social Science and Humanities (CRASSH) at the University of Cambridge supported my work during the latter part of the gestation of this volume. Earlier phases were conducted while I was employed by the National University of Singapore, the Correspondence of Alfred Russel Wallace Project at the Open University and the History of Ideas Department at the University of Aarhus, Denmark. I owe a very great debt to Jim Secord and Janet Browne whose generous support and guidance have made this and so much else possible. Words are not sufficient to express both how indebted I am to them and my great respect and admiration. It is an honour to have their contribution to this volume. Sue Asscher, associate editor for Darwin Online, has (in addition to much other work) proof-read and corrected almost every one of Darwin’s shorter publications for the website and thereby made a voluntary contribution that is difficult to exaggerate. Her tireless efforts and painstaking attention to detail made it an honour to work with her. Not only I, but the many readers of Darwin Online, owe her a great deal of gratitude. Kees Rookmaaker, research associate with Darwin Online, made an enormous contribution to this work both in terms of research, checking notes and acquiring many copies of Darwin’s shorter publications from around the world. Some of them, I must apologize, more than once when my sometimes out-of-date lists of references were repetitive. He has also been a constant source of advice and encouragement and it has been my privilege to work with him. Gordon Chancellor kindly checked the notes for the many geological and Beagle items and offered many helpful suggestions and composed a few endnotes (always attributed). His enthusiasm and generously shared scholarship were a great benefit for which I am very grateful. There are too few such scholars who combine, as he does, daunting knowledge of the subject, infectious enthusiasm and the greatest possible kindness and readiness to help. Both this book and I owe a very great debt to Duncan Porter who kindly, even courageously, not only checked the endnotes of the many botanical items, but read over all of the botanical shorter publications themselves and provided many suggestions and corrections. His generous assistance xxiv

Acknowledgements

xxv

on many points, unparalleled knowledge and expertise are a very great contribution for which I am particularly grateful. The editors of the Correspondence, especially Shelley Innes and Alison Pearn, provided much important assistance identifying a mistaken letter on the online versions, answering many queries and providing details from the unpublished correspondence. Rosemary Clarkson kindly helped looking into queries and sent photocopies of rare items. Samantha Evans helped with details on preparing the final print volume. I am especially indebted to Jim Secord, Director of the Darwin Correspondence Project, for his enormously kind and helpful commitment to promote Darwin scholarship and for making details of the unpublished correspondence available to me, though unfortunately there was not enough time to fully utilize them in this volume. Nicholas Jackson translated the Darwin letter in Italian (F1970) at very short notice. David Butterfield and David Sedley kindly translated the surrounding Latin paragraph from Linnaeus (F350). Tori Reeve, the Curator of Down House, helpfully showed me Darwin’s copies of the books by Otto Hahn. Daniel Glaser helpfully took the trouble to pass on an unrecorded Darwin publication (F2006). George Beccaloni kindly looked over some of the entomological items and offered helpful advice. I have received assistance from many others who are no less deserving of thanks here including Cordula van Wyhe; Patrick Zutshi, Adam Perkins and Godfrey Waller of Cambridge University Library; Tim Eggington and Dawn Moutrey of the Whipple Library, Cambridge; Judith Magee and Lorraine Portch of the Natural History Museum, London; Candace Guite, Colin Higgins, and Ann Keith of the Library of Christ’s College, Cambridge; Sarah Humbert of the Earth Sciences Library, Cambridge; New College Library, Edinburgh University Library; The University Museum of Zoology, Cambridge; the Rutherford B. Hayes Presidential Center, Spiegel Grove, Fremont, Ohio, USA; Alexandra Caccamo, Librarian at the National Botanic Gardens, Dublin; Heinz Alfred Gemeinhardt of the Stadtsarchiv Reutlingen; the Library of the National University of Singapore; Martin Rudwick; Tom Glick; Angus Carroll; The Master, Fellows and Scholars of Christ’s College, Cambridge; the Sedgwick Museum of Earth Sciences, Cambridge; English Heritage (Darwin Collection at Down House) and the Darwin, Keynes and Barlow families. Gordon Chancellor, Jon Hodge, Jim Secord and Gregory Radick provided helpful suggestions for the introduction. Corrections or suggestions for the online versions of the texts or notes were kindly sent by Andrew Sclater, Marsha Richmond, J. David Archibald, Rebecca Stott, David Allan Feller, Shelley Innes, Randal Keynes, John S. Wilkins, George Beccaloni and David Clifford. I apologize to any whose names I have inadvertently omitted. I am grateful to the many scholars whose works I have consulted and relied upon in research for this volume even if a specific mention has not been made. My greatest debt is to the Correspondence, their Calendar and database of persons and extended bibliography are indispensable aids. It would have been impossible to complete this work in time without this massive mountain of Darwin scholarship. I am also indebted to the workers behind online text collections such as Google books, The Internet Archive, Making of America, JSTOR, Gallica and many others which made a trip to the library on countless occasions unnecessary

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as a work could be found online or vague references could be identified by electronic searching that would never have been otherwise identified. I have benefited enormously over the years from conversation and correspondence with James Moore, Randal Keynes, Sandra Herbert, Marsha Richmond, Jim Secord, Janet Browne, Richard Keynes, Fred Burkhardt, Adrian Desmond, Aileen Fyfe, Frank Sulloway, Mario di Gregorio, Nick Gill, Pietro Corsi, Rebecca Stott, Robert Olby, Duncan Porter, Jon Topham, Ludmilla Jordanova, and Peter Kjærgaard. For permission to reproduce unpublished material in their possession I am grateful to William Huxley Darwin and the Syndics of Cambridge University Library. The ‘appeal’ woodcut is reproduced by kind permission of the Master and Fellows of Christ’s College, Cambridge. Cambridge University Press gave permission to reproduce passages from the Correspondence. I would like to repeat my thanks here to The Charles Darwin Trust and Mary Whitear for permission to reproduce Freeman’s Bibliographical Handlist on Darwin Online. Finally I wish to thank my editor at Cambridge University Press, Jacqueline Garget, and the team at the Press who helped with the illustrations and typesetting, two anonymous referees for helpful suggestions and Margot Levy for her superb index.

Charles Darwin’s Shorter Publications 1829–1883

1829–1832. [Records of captured insects]. In Stephens, J. F., Illustrations of British entomology; or, a synopsis of indigenous insects etc. London: Baldwin & Cradock, vols. 1–5. F19681 Haustellata vol. 2 (appendix) (1 June 1829) |200| Graphiphora plecta. “Cambridge.” – C. Darwin, Esq. Mandibulata vol. 2 (appendix) (15 June 1829) |188| Ocys tempestivus. “Cambridge.” – C. Darwin, Esq. |190| Elaphrus uliginosus. “Cambridge, in plenty, 1829.” – C. Darwin, Esq. |191| Blethisa multipunctata “In great abundance near Cambridge in 1829.” – C. Darwin, Esq. Haliplus elevatusa “Near Cambridge, 1829.” – C. Darwin, Esq. Hygrotus scitulus “Near Cambridge.” – C. Darwin, Esq. |192| Hydroporus areolatus “Cambridge.” – C. Darwin, Esq. |194| Colymbetes pulverosus “In profusion near Cambridge.” – C. Darwin, Esq. Colymbetes notatus “In abundance near Cambridge.” – C. Darwin, Esq. Colymbetes exoletus “Abundantly near Cambridge.” – C. Darwin, Esq. Colymbetes agilis “In profusion near Cambridge in 1829.” – C. Darwin, Esq. Colymbetes adspersus “Plentiful near Cambridge in 1829.” – C. Darwin, Esq. |195| Hydaticus hybneri “Near Cambridge, 1829.” – C. Darwin, Esq. Dytiscus (Leionotus) conformis “Near Cambridge, not rare, 1829.” – C. Darwin, Esq. Mandibulata vol. 3 (30 April 1830) |7| [Ptomaphagus] anisotomoides “Shropshire.” – C. Darwin, Esq. [Ptomaphagus] wilkinii “Salop.” – C. Darwin, Esq. |9| [Catops] sericeus “Cambridge and Salop.” – C. Darwin, Esq. |14| [Choleva] angustata “North Wales.” – C. Darwin, Esq. [Choleva] agilis “North Wales.” – C. Darwin, Esq. |19| Ne[crophorus] interruptus “Found with the preceeding [vestigator] but occurs much less frequently.” – Rev. L. Jenyns and C. Darwin Esq. |33| [Nitidulaa] punctatissima “Shropshire.” – C. Darwin, Esq. |38| Ni[tidula] obsoleta “Cambridgeshire and North Wales.” – C. Darwin, Esq. 1

2

[1835]. [Extracts from letters addressed to Professor Henslow]

|41| Ni[tidula] limbata “North Wales.” – C. Darwin, Esq. |79| Cr[yptophagus] typhae “Cambridgeshire and North Wales.” – C. Darwin, Esq. |104| [Crypta] bipunctata “Near Cambridge.” – C. Darwin, Esq. |154| Hi[ster] quadristriatus “Barmouth.” – Rev F. W. Hope, and C. Darwin, Esq. |182| [Geotrupes] laevis “Barmouth and North Wales.” – Rev F. W. Hope and C. Darwin, Esq. |242| [Trachys] pygmaea “Cambridge.” – C. Darwin, Esq. |266| [Darwin is mentioned, though not quoted, in a note on Ctenicerus cupreus, as captured by C. Darwin, Esq. et al in North Wales] |279| [Campylus] linearis “Woods near Cambridge.” – C. Darwin, Esq. Mandibulata vol. 4 (1831) |118| [Otiorhynchus] atroapterus “Barmouth.” – Rev F. W. Hope and C. Darwin, Esq. |274| [Donacia] nigra “Near Cambridge.” – C. Darwin, Esq. Mandibulata (appendix) vol. 5 (1832) |394| Col. branchiatus. Taken in North Wales by C. Darwin, Esq.

1

CD was very proud when, as a student at Christ’s College, Cambridge, his name appeared in James Francis Stephens (1792–1852), Entomology. As CD later recalled in his Autobiography (pp. 62–3): But no pursuit at Cambridge was followed with nearly so much eagerness or gave me so much pleasure as collecting beetles. It was the mere passion for collecting, for I did not dissect them and rarely compared their external characters with published descriptions, but got them named anyhow. I will give a proof of my zeal: one day, on tearing off some old bark, I saw two rare beetles and seized one in each hand; then I saw a third and new kind, which I could not bear to lose, so that I popped the one which I held in my right hand into my mouth. Alas it ejected some intensely acrid fluid, which burnt my tongue so that I was forced to spit the beetle out, which was lost, as well as the third one. I was very successful in collecting and invented two new methods; I employed a labourer to scrape during the winter, moss off old trees and place [it] in a large bag, and likewise to collect the rubbish at the bottom of the barges in which reeds are brought from the fens, and thus I got some very rare species. No poet ever felt more delight at seeing his first poem published than I did at seeing in Stephen’s Illustrations of British Insects the magic words, “captured by C. Darwin, Esq.” It has been remarked that this exact wording was not printed in Stephens. But the entry in 3: 266 reads: ‘captured by the Rev. F. W. Hope and C. Darwin, Esq., in North Wales’. There are 92 words quoted from CD in 31 entries, with a further two entries naming him as the collector but without quotation. See Freeman 1977 and Darwin’s insects.

[1835]. [Extracts from letters addressed to Professor Henslow]. Cambridge: [privately printed]. F1 For Private Distribution1 The following pages contain Extracts from letters addressed to Professor Henslow2 by C. Darwin, Esq. They are printed for distribution among the Members of the Cambridge Philosophical Society, in consequence of the interest which has been excited by some of the Geological notices which they contain, and which were read at a Meeting of the Society on the 16th of November 1835.

[1835]. [Extracts from letters addressed to Professor Henslow]

3

The opinions here expressed must be viewed in no other light than as the first thoughts which occur to a traveller respecting what he sees, before he has had time to collate his Notes, and examine his Collections, with the attention necessary for scientific accuracy. Cambridge, Dec. 1, 1835. |2| |3| Extracts, &c. Rio de Janeiro, May 18, 1832. We started from Plymouth on the 27th December 1831—At St Jago3 (Cape de Verd Islands) we spent three weeks. The geology was pre-eminently interesting, and I believe quite new: there are some facts on a large scale, of upraised coast that would interest Mr. Lyell.4 St Jago is singularly barren, and produces few plants or insects; so that my hammer was my usual companion. On the coast I collected many marine animals, chiefly gasteropodous mollusca (I think some new). I examined pretty accurately a Caryophyllia,5 and, if my eyes were not bewitched, former descriptions have |4| not the slightest resemblance to the animal. I took several specimens of an Octopus, which possessed a most marvellous power of changing its colours; equalling any chamelion, and evidently accommodating the changes to the colour of the ground which it passed over. We then sailed for Bahia, and touched at the rock of St Paul. This is a serpentine formation. After touching at the Abrothos,6 we arrived here on April 4th. A few days after arriving, I started on an expedition of one hundred and fifty miles to Rio Macao,7 which lasted eighteen days. I am now collecting fresh water and land animals: if what was told me in London is true, viz. that there are no small insects in the collections from the Tropics, I tell entomologists to look out and have their pens ready for describing. I have taken as minute (if not more so) as in England, Hydorpori, Hygroti, Hydrobii, Pselaphi, Staphylini, Curculiones, Bembidia, &c. &c. It is exceedingly interesting to observe the difference of genera and species from those which I know; it is however much less than I had expected. |5| I have just returned from a walk, and as a specimen how little the insects are known, Noterus, according to Dic. Class.8 consists solely of three European species. I, in one haul of my net, took five distinct species. At Bahia, the pegmatite and gneiss in beds had the same direction as was observed by Humboldt9 to prevail over Columbia, distant thirteen hundred miles. Monte Video, Aug. 15, 1832. My collection of plants from the Abrothos is interesting, as I suspect it contains nearly the whole flowering vegetation.

4

[1835]. [Extracts from letters addressed to Professor Henslow]

I made an enormous collection of Arachnidæ at Rio. Also a good many small beetles in pill-boxes: but it is not the best time of year for the latter. Amongst the lower animals, nothing has so much interested me as finding two species of elegantly coloured planariæ10 (?) inhabiting the dry forest! The false relation they bear to snails is the most extraordinary thing of the kind I have ever seen. In the same genus (or more truly, family) some of the marine species possess an organization so marvellous, |6| that I can scarcely credit my eyesight. Every one has heard of the discoloured streaks of water in the equatorial regions. One I examined was owing to the presence of such minute Oscillatoria,11 that in each square inch of surface there must have been at least one hundred thousand present. I might collect a far greater number of specimens of invertebrate animals if I took up less time over each: but I have come to the conclusion, that two animals with their original colour and shape noted down, will be more valuable to naturalists than six with only dates and place. At this present minute we are at anchor in the mouth of the river: and such a strange scene it is. Every thing is in flames—the sky with lightning—the water with luminous particles— and even the very masts are pointed with a blue flame. Monte Video, Nov. 24, 1832. We arrived here on the 24th of October, after our first cruize on the coast of Patagonia, north of the Rio Negro. |7| I had hoped for the credit of dame Nature, no such country as this last existed; in sad reality we coasted along two hundred and forty miles of sand hillocks; I never knew before, what a horrid ugly object a sand hillock is: the famed country of the Rio Plata in my opinion is not much better; an enormous brackish river bounded by an interminable green plain is enough to make any naturalist groan. I have been very lucky with fossil bones; I have fragments of at least six distinct animals; as many of these are teeth, shattered and rolled as they have been, I trust they will be recognized. I have paid all the attention I am capable of, to their geological site; but of course it is too long a story for a letter. 1st. the tarsi and meta-tarsi, very perfect, of a cavia;12 2d. the upper jaw and head of some very large animal, with four square hollow molars, and the head greatly produced in front. I at first thought it belonged either to the megalonyx or megatherium.13 In confirmation of this, in the same formation, I found a large surface of the osseous polygonal plates, which “late observations” (what are they?) have shewn to belong to the megatherium. Immediately I saw them I thought they must belong to an enormous armadillo, living species of which genus are so abundant here. 3d. The lower jaw of some large animal, which, from the molar teeth I should think belonged to the edentata;14 4th. large molar teeth, which in some |8| respects would seem to belong to some enormous species of rodentia; 5th. also some smaller teeth belonging to the same order, &c. &c.—They are mingled with marine shells, which appear to me identical with existing species. But since they were deposited in their beds, several geological changes have taken place in the country.

[1835]. [Extracts from letters addressed to Professor Henslow]

5

There is a poor specimen of a bird, which to my unornithological eyes, appears to be a happy mixture of a lark, pigeon, and snipe. Mr Mac Leay15 himself never imagined such an inosculating16 creature. I have taken some interesting amphibia; a fine bipes;17 a new Trigonocephalus,18 in its habits beautifully connecting Crotalus19 and Viperus:20 and plenty of new (as far as my knowledge goes) saurians. As for one little toad, I hope it may be new, that it may be christened “diabolicus.” Milton must allude to this very individual, when he talks of “squat like a toad.”21 Amongst the pelagic crustaceæ, some new and curious genera. Among Zoophites some interesting animals. As for one Flustra,22 if I had not the specimen to back me, nobody would believe in its most anomalous structure. But as for novelty, all this is nothing to a family of pelagic animals, which at first sight appear like Medusa, but are really highly organized. |9| I have examined them repeatedly, and certainly from their structure it would be impossible to place them in any existing order. Perhaps Salpa23 is the nearest animal; although the transparency of the body is almost the only character they have in common. We have been at Buenos Ayres for a week. It is a fine large city; but such a country; every thing is mud; you can go no where, you can do nothing for mud. In the city I obtained much information about the banks of the Uruguay. I hear of limestone with shells, and beds of shells in every direction. I purchased fragments of some enormous bones, which I was assured belonged to the former giants!! April 11, 1833. We are now running up from the Falkland Islands to the Rio Negro (or Colorado.) It is now some months since we have been at a civilized port; nearly all this time has been spent in the most southern part of Tierra del Fuego. It is a detestable place; gales succeed gales at such short intervals, that it is difficult to do any thing. We were twenty-three days off Cape Horn, and could |10| by no means get to the westward.—We at last ran into harbour, and in the boats got to the west of the inland channels.—With two boats we went about three hundred miles; and thus I had an excellent opportunity of geologizing and seeing much of the savages. The Fuegians are in a more miserable state of barbarism than I had expected ever to have seen a human being. In this inclement country they are absolutely naked, and their temporary houses are like those which children make in summer with boughs of trees. The climate in some respects is a curious mixture of severity and mildness; as far as regards the animal kingdom the former character prevails; I have in consequence not added much to my collections. The geology of this part of Tierra del Fuego was to me very interesting. The country is non-fossiliferous, and a common-place succession of granitic rocks and slates: attempting to make out the relation of cleavage, strata, &c. &c. was my chief amusement. The Southern ocean is nearly as sterile as the continent it washes. Crustaceæ have afforded me most work.

6

[1835]. [Extracts from letters addressed to Professor Henslow]

I found a Zoea,24 of most curious form, its body being only one-sixth the length of the two spears. I am convinced, from its structure and other reasons, it is |11| a young Erichthus.25 I must mention part of the structure of a Decapod,26 it is so very anomalous: the last pair of legs are small and dorsal, but instead of being terminated by a claw, as in all others, it has three curved bristle-like appendages; these are finely serrated and furnished with cups, somewhat resembling those of the Cephalopods. The animal being pelagic, this beautiful structure enables it to hold on to light floating objects. I have found out something about the propagation of that ambiguous tribe the Corallines. After leaving Tierra del Fuego, we sailed to the Falklands. I had here the high good fortune to find amongst the most primitive looking rocks, a bed of micaceous sandstone, abounding with Terebratula27and its sub-genera, and Entrochites.28 As this is so remote a locality from Europe, I think the comparison of these impressions with those of the oldest fossiliferous rocks of Europe will be pre-eminently interesting.29 Of course they are only models and casts; but many of them are very perfect. Rio de la Plata, July 18, 1833. The greater part of the winter has been passed in this river at Meldonado.30 |12| We have got almost every bird in this neighbourhood, (Meldonado) about eighty in number, and nearly twenty quadrupeds. In a few days we go to the Rio Negro to survey some banks. The geology must be very interesting. It is near the junction of the Megatherium and Patagonian cliffs. From what I saw of the latter, in one half hour, in St Joseph’s bay, they would be well worth a long examination. Above the great oyster-bed there is one of gravel, which fills up inequalities in its interior; and above this, and therefore high out of the water, is one of such modern shells that they retain their colour and emit a bad smell when burnt. Patagonia must clearly have lately risen from the water. Monte Video, November 12, 1833. I left the Beagle at the Rio Negro, and crossed by land to Buenos Ayres. There is now carrying on a bloody war of extermination against the Indians, by which I was able to make this passage. But at the best it is sufficiently dangerous, and till now very rarely travelled. It is the most wild, dreary plain imaginable, without settled inhabitant or head of |13| cattle. There are military “postas” at wide intervals, by which means I travelled. We lived for many days on deer and ostriches, and had to sleep in the open camp. I had the satisfaction of ascending the Tierra de la Ventana, a chain of mountains between three and four thousand feet high, the very existence of which is scarcely known beyond the Rio Plata. After resting a week at Buenos Ayres, I started for St Fé. On the road the geology was interesting. I found two great groups of immense bones, but so very soft as to render it impossible to remove them. I think, from a fragment of one of the teeth, they belonged to the Mastodon.31 In the Rio Carcarana, I got a tooth which puzzles even my conjectures. It looks

[1835]. [Extracts from letters addressed to Professor Henslow]

7

like an enormous gnawing one. At St Fé, not being well, I embarked and had a fine sail of three hundred miles down that princely river the Parana. When I returned to Buenos Ayres, I found the country upside down with revolutions, which caused me much trouble. I at last got away and joined the Beagle. E. Falkland Island, March, 1834. I have been alarmed by your expression “cleaning all the bones,” as I am afraid the printed numbers will be lost: the reason I am so anxious they should |14| not be, is, that a part were found in a gravel with recent shells, but others in a very different bed. Now with these latter there were bones of an Agouti,32 a genus of animals, I believe, peculiar to America, and it would be curious to prove that some one of the same genus coexisted with the megatherium; such, and many other points entirely depend on the numbers being carefully preserved. I collected all the plants which were in flower on the coast of Patagonia, at Port Desire, and St Julian; also on the eastern parts of Tierra del Fuego, where the climate and features of Tierra del Fuego and Patagonia are united. The soil of Patagonia is very dry, gravelly, and light. In East Tierra, it is gravelly, peaty, and damp. Since leaving the Rio Plata I have had some opportunities of examining the great southern Patagonian formation. I have a good many shells; from the little I know of the subject, it must be a tertiary formation, for some of the shells (and corallines) now exist in the sea. Others, I believe, do not. This bed, which is chiefly characterized by a great oyster, is covered by a very curious bed of porphyry pebbles, which I have traced for more than seven hundred miles. But the most curious fact is, that the whole of the east coast of the southern part of South America has been elevated from the ocean, since a period during which |15| muscles have not lost their blue colour. At Port St Julian I found some very perfect bones of some large animal, I fancy a Mastodon: the bones of one hind extremity are very perfect and solid. This is interesting, as the latitude is between 49° and 50°, and the site far removed from the great Pampas, where bones of the narrow toothed Mastodon are so frequently found. By the way this Mastodon and the Megatherium, I have no doubt, were fellow brethren in the ancient plains. Relics of the Megatherium I have found at a distance of nearly six hundred miles in a north and south line. In Tierra del Fuego I have been interested in finding some sort of ammonite (also I believe found by Capt. King)33 in the slate near Port Famine; and on the eastern coast there are some curious alluvial plains, by which the existence of certain quadrupeds in the islands can clearly be accounted for. There is a sandstone with the impression of leaves like the common beech tree; also modern shells, &c., and on the surface of the table land there are, as usual, muscles with their blue colour, &c. I have chiefly been employed in preparing myself for the South Sea, and examining the polypi of the smaller corallines in these latitudes. Many in themselves are very curious, and I think undescribed: there was one appalling one, allied to a Flustra, which I dare say I mentioned having found to the northward, where |16| the cells have a moveable organ (like a vulture’s head, with a dilatable beak), fixed on the edge. But what is of more general

8

[1835]. [Extracts from letters addressed to Professor Henslow]

interest, is the unquestionable (as it appears to me) existence of another species of ostrich34 besides the Struthio ostrea. All the Gauchos and Indians state it is the case: and I place the greatest faith in their observations. I have the head, neck, and piece of skin, feathers, and legs of one. The differences are chiefly in the colour of the feathers and scales; in the legs being feathered below the knees; also in its modification, and geographical distribution. Valparaiso, July 24, 1834. After leaving the Falklands, we proceeded to the Rio Santa Cruz; followed up the river till within twenty miles of the Cordilleras:35 unfortunately want of provisions compelled us to return. This expedition was most important to me, as it was a transverse section of the great Patagonian formation. I conjecture (an accurate examination of the fossils may possibly determine the point) that the main bed is somewhere about the meiocene period (using Mr Lyell’s expression); judging from what I have seen of the present shells of Patagonia. This bed contains an enormous mass of lava. This is of some |17| interest, as being a rude approximation to the age of the volcanic part of the great range of the Andes. Long before this it existed as a slate and porphyritic line of hills. I have collected a tolerable quantity of information respecting the various periods and forms of elevations of these plains. I think these will be interesting to Mr Lyell. I had deferred reading his third volume till my return; you may guess how much pleasure it gave me; some of his wood-cuts came so exactly into play, that I have only to refer to them, instead of redrawing similar ones. The valley of Santa Cruz appears to me a very curious one; at first it quite baffled me. I believe I can shew good reasons for supposing it to have been once a northern strait, like that of Magellan. In Tierra del Fuego I collected and examined some corallines: I have observed one fact which quite startled me. It is, that in the genus Sertularia36 (taken in its most restricted form as by Lamouroux),37 and in two species which, excluding comparative expressions, I should find much difficulty in describing as different, the polypi quite and essentially differed in all their most important and evident parts of structure. I have already seen enough to be convinced that the present families of corallines, as arranged by Lamarck,38 Cuvier,39 &c. are highly artificial. It appears to me, that they are in the same |18| state in which shells were, when Linnæus40 left them for Cuvier to re-arrange. It is most extraordinary I can no where see in my books a single description of the polypus of any one coral (excepting Lobularia (Alcyonium) of Savigny).41 I found a curious little stony Cellaria (a new genus), each cell provided with a long toothed bristle capable of various and rapid motions. This motion is often simultaneous, and can be produced by irritation. This fact, as far as I see, is quite isolated in the history (excepting of the Flustra, with an organ like a vulture’s head) of Zoophites. It points out a much more intimate relation between the polypi, than Lamarck is willing to allow. I forget whether I mentioned having seen something of the manner of propagation in that most ambiguous family, the corallines: I feel pretty well convinced that if they are not plants, they are not Zoophites: the “gemmule” of a Halimeda contains several articulations united, ready to burst their envelope and become attached to some

[1835]. [Extracts from letters addressed to Professor Henslow]

9

basis. I believe that in Zoophites universally, the gemmule produces a single polypus, which afterwards or at the same time grows with its cell, or single articulation. The Beagle left the strait of Magellan in the middle of winter: she found her road out by a wild unfrequented channel; well might Sir J. Nasborough42 call the west coast South Desolation, “because it is so desolate a land |19| to behold.” We were driven into Chiloe, by some very bad weather. An Englishman gave me three specimens of that very fine lucanoidal insect,43 which is described in the Cambridge Philosophical Transactions,44 two males and one female. I find Chiloe is composed of lava and recent deposits. The lavas are curious, from abounding with or rather being composed of pitchstone. We arrived here the day before yesterday; the views of the distant mountains are most sublime and the climate delightful: after our long cruise in the damp gloomy climates of the South, to breathe a clear dry air, and feel honest warm sunshine, and eat good fresh roast beef, must be the summum bonum of human life. I do not like the looks of the rocks half so much as the beef, there is too much of those rather insipid ingredients, mica, quartz, and feldspar. Shortly after arriving here I set out on a geological excursion, and had a very pleasant ramble about the base of the Andes. The whole country appears composed of breccias, (and I imagine slates) which universally have been modified, and often completely altered by the action of fire; the varieties of porphyry thus produced are endless, but no where have I yet met with rocks which have flowed in a stream; dykes of greenstone are very numerous. Modern volcanic action is entirely shut up in the |20| very central parts (which cannot now be reached on account of the snow) of the Cordilleras. To the south of the Rio Maypo, I examined the tertiary plains already partially described by M. Gay.45 The fossil shells appear to me to differ more widely from the recent ones, then in the great Patagonian formation; it will be curious if an eocene and meiocene formation (recent there is abundance of) could be proved to exist in South America as well as in Europe. I have been much interested by finding abundance of recent shells at an elevation of thirteen hundred feet; the country in many places is scattered over with shells, but these are all littoral ones! So that I suppose the thirteen hundred feet elevation must be owing to a succession of small elevations, such as in 1822. With these certain proofs of the recent residence of the ocean over all the lower parts of Chili, the outline of every view and the form of each valley possesses a high interest. Has the action of running water or the sea formed this ravine? was a question which often arose in my mind, and was generally answered by my finding a bed of recent shells at the bottom. I have not sufficient arguments, but I do not believe that more than a small fraction of the height of the Andes has been formed within the tertiary period. |21| Valparaiso, March 1835. We are now lying becalmed off Valparaiso, and I will take the opportunity of writing a few lines to you. The termination of our voyage is at last decided on. We leave the coast of America in the beginning of September, and hope to reach England in the same month of 1836.

10

[1835]. [Extracts from letters addressed to Professor Henslow]

You will have heard an account of the dreadful earthquake of the 20th of February. I wish some of the geologists, who think the earthquakes of these times are trifling, could see the way in which the solid rock is shivered. In the town there is not one house habitable; the ruins remind me of the drawings of the desolated eastern cities. We were at Valdivia at the time, and felt the shock very severely. The sensation was like that of skating over very thin ice; that is, distinct undulations were perceptible. The whole scene of Concepcion and Talcuana is one of the most interesting spectacles we have beheld since leaving England. Since leaving Valparaiso, during this cruise, I have done little excepting in geology. In the modern tertiary strata I have examined four bands of disturbance, which reminded me on a small scale of the famous tract in the Isle of Wight. In one spot there were beautiful examples of three different forms of upheaval. In two cases I think I can show that the inclination is owing to the presence |22| of a system of parallel dykes traversing the inferior mica slate. The whole of the coast from Chiloe to the south extreme of the Peninsula of Tres Montes is composed of the latter rock; it is traversed by very numerous dykes, the mineralogical nature of which will, I suspect, turn out very curious. I examined one grand transverse chain of granite, which has clearly burst up through the overlying slate. At the Peninsula of Tres Montes there has been an old volcanic focus, which corresponds to another in the north part of Chiloe. I was much pleased at Chiloe by finding a thick bed of recent oyster-shells, &c. capping the tertiary plain, out of which grew large forest trees. I can now prove that both sides of the Andes have risen in this recent period to a considerable height. Here the shells were three hundred and fifty feet above the sea. In Zoology I have done but very little; excepting a large collection of minute diptera and hymenoptera from Chiloe. I took in one day, Pselaphus, Anaspis, Latridius, Leiodes, Cercyon, and Elmis, and two beautiful true Carabi; I might have fancied myself collecting in England. A new and pretty genus of nudibranch mollusca which cannot crawl on a flat surface, and a genus in the family of balanidæ,46 which has not a true case, but lives in minute cavities in the shells of the concholepas,47 are nearly the only two novelties. |23| Valparaiso, April 18, 1835. I have just returned from Mendoza, having crossed the Cordilleras by two passes. This trip has added much to my knowledge of the geology of the country. I will give a very short sketch of the structure of these huge mountains. In the Portillo pass (the more southern one) travellers have described the Cordilleras to consist of a double chain of nearly equal altitude, separated by a considerable interval. This is the case: and the same structure extends northward to Uspellata.48 The little elevation of the eastern line (here not more than six thousand or seven thousand feet) has caused it almost to be overlooked. To begin with the western and principal chain, where the sections are best seen; we have an enormous mass of a porphyritic conglomerate resting on granite. This latter rock seems to form the nucleus of the whole mass, and is seen in the deep lateral valleys, injected amongst, upheaving, overturning in the most extraordinary manner, the overlying strata. On the bare sides of the mountains, the complicated dykes and wedges of variously coloured rocks,

[1835]. [Extracts from letters addressed to Professor Henslow]

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are seen traversing in every possible form and shape the same formations, which, by their intersections, prove a succession of violences. The stratification in all the mountains is beautifully distinct, and owing to a variety in their colouring, can be seen at great |24| distances. I cannot imagine any part of the world presenting a more extraordinary scene of the breaking up of the crust of the globe, than these central peaks of the Andes. The upheaval has taken place by a great number of (nearly) north and south lines;* which in most cases has formed as many anticlinal and synclinal ravines. The strata in the highest pinnacles are almost universally inclined at an angle from 70° to 80°. I cannot tell you how much I enjoyed some of these views; it is worth coming from England, once to feel such intense delight. At an elevation of from ten to twelve thousand feet, there is a transparency in the air, and a confusion of distances, and a sort of stillness, which give the sensation of being in another world; and when to this is joined the picture so plainly drawn of the great epochs of violence, it causes in the mind a most strange assemblage of ideas. The formation which I call porphyritic conglomerates, is the most important and most developed in Chili. From a great number of sections, I find it to be a true coarse conglomerate or breccia, which passes by every step, in slow gradation, into a fine clay-stone porphyry; the pebbles and cement becoming porphyritic, till at last all is blended in one compact rock. The porphyries are excessively abundant in this chain, and I feel sure that at least four-fifths of them have been thus |25| produced from sedimentary beds in situ. There are also porphyries which have been injected from below amongst the strata, and others ejected which have flowed in streams: and I could shew specimens of this rock, produced in these three methods, which cannot be distinguished. It is a great mistake to consider the Cordilleras (here) as composed only of rocks which have flowed in streams. In this range I nowhere saw a fragment which I believe to have thus originated, although the road passes at no great distance from the active volcanos. The porphyries, conglomerates, sandstone, quartzone-sandstone, and limestones alternate and pass into each other many times (overlying clay-slate, when not broken through by the granite.) In the upper parts the sandstone begins to alternate with gypsum, till at last we have this substance of a stupendous thickness. I really think the formation is in some places (it varies much) nearly two thousand feet thick. It occurs often with a green (Epidote?) siliceous sandstone and snow-white marble: and resembles that found in the Alps, from containing large concretions of a crystalline marble of a blackish-gray colour. The upper beds, which form some of the higher pinnacles, consist of layers of snow-white gypsum and red compact sandstone, from the thickness of paper to a few feet, alternating in an endless round. The rock has a most curiously painted appearance. At the pass of the Puquenas49 in this formation, where a black rock (like clay-slate, |26| without many laminæ) and pale limestone have replaced the red sandstone, I found abundant impressions of shells. The elevation must be between twelve thousand and thirteen thousand feet. A shell which I believe is a Gryphæa is the most abundant. There is also an Ostrea, Turritella, Ammonites, small bivalve, Terebratula (?) Perhaps some good conchologist will be able to give a guess to what grand division of the continents of Europe these organic remains bear most *

Of dykes?

12

[1835]. [Extracts from letters addressed to Professor Henslow]

resemblance. They are exceedingly imperfect and few; the Gryphites50 are most perfect. It was late in the season, and the situation particularly dangerous, from snow-storms. I did not dare to delay, otherwise a good harvest might have been reaped. So much for the western line. In the Portillo Pass, proceeding eastward, I met with an immense mass of a conglomerate, dipping to the west 45°, which rests on micaceous sandstone, &c. upheaved, converted into quartz rock, penetrated by dykes, from a very grand mass of protogene (large crystals of quartz, red feldspar, and a little chlorite.) Now this conglomerate, which reposes on and dips from the protogene at an angle of 45°, consists of the peculiar rocks of the first described chain, pebbles of the black rock with shells, green sandstone, &c. &c. It is here manifest also, that the upheaval (and deposition at least of part) of the grand eastern chain is entirely posterior to the western. To the north, in the Uspellata pass, we have also a fact of the same |27| class. Bear this in mind; it will help to make you believe what follows. I have said the Uspellata range is geologically, although only six thousand or seven thousand feet, a continuation of the grand eastern chain. It has its nucleus of granite, consisting of grand beds of various crystalline rocks, which I can feel no doubt are subaqueous lavas alternating with sandstone, conglomerates, and white aluminous beds (like decomposed feldspar) with many other curious varieties of sedimentary deposits. These lavas and sandstones alternate very many times, and are quite conformable one to the other. During two days of careful examination I said to myself at least fifty times, how exactly like, only rather harder, these beds are to those of the upper tertiary strata of Patagonia, Chiloe, and Concepcion, without the possibility of their identity ever having occurred to me. At last there was no resisting the conclusion. I could not expect shells, for they never occur in this formation; but lignite or carbonaceous shale ought to be found. I had previously been exceedingly puzzled by meeting in the sandstone with thin layers (a few inches to some feet thick) of a brecciated pitchstone.51 I now strongly suspect that the underlying granite has altered such beds into this pitchstone. The silicified wood (particularly characteristic of the formation) was yet absent; but the conviction that I was on the tertiary strata was so strong in my mind by this time, that on the third day, in the midst of lavas, and heaps of |28| granite, I began an apparently forlorn hunt in search of it. How do you think I succeeded? In an escarpement of compact greenish sandstone I found a small wood of petrified trees in a vertical position, or rather the strata were inclined about 20° or 30° to one point, and the trees 70° to the opposite; that is, they were before the tilt truly vertical. The sandstone consists of many horizontal layers, and is marked by the concentric lines of the bark (I have a specimen).52 Eleven are perfectly silicified, and resemble the dicotyledonous wood which I found at Chiloe and Concepcion: the others, thirty to thirty-four in number, I only know to be trees from the analogy of form and position; they consist of snow-white columns (Like Lot’s wife) of coarsely crystalized carbonate of lime. The largest shaft is seven feet. They are all close together, within one hundred yards, and about the same level; no where else could I find any. It cannot be doubted that the layers of fine sandstone have quietly been deposited between a clump of trees, which were fixed by their roots. The sandstone rests on lava, is covered by a great bed, apparently about one thousand feet thick, of black augitic lava, and over this there are at least five grand alternations of such rocks and aqueous sedimentary

[1835]. [Extracts from letters addressed to Professor Henslow]

13

deposits; amounting in thickness to several thousand feet. I am quite afraid of the only conclusion which I can draw from this fact, namely, that there must have been a depression in the surface of the land to that amount. But |29| neglecting this consideration, it was a most satisfactory support of my presumption of the tertiary age of this eastern chain. (I mean by tertiary, that the shells of the period were closely allied to, and some identical with, those which now lie in the lower beds of Patagonia.) A great part of the proof must remain upon my ipse dixit of a mineralogical resemblance to those beds whose age is known. According to this view granite, which forms peaks of a height probably of fourteen thousand feet, has been fluid in the tertiary period: strata of that period have been altered by its heat, and are traversed by dykes from the mass: are now inclined at high angles, and form regular or complicated anticlinal lines. To complete this climax, these same sedimentary strata and lavas are traversed by very numerous true metallic veins of iron, copper, arsenic, silver, and gold, and these can be traced to the underlying granite. A gold mine has been worked close to the clump of silicified trees. When you see my specimens, sections, and account, you will think there is pretty strong presumptive evidence of the above facts. They appear very important; for the structure and size of this chain will bear comparison with any in the world: and that all this should have been produced in so very recent a period is indeed remarkable. In my own mind I am quite convinced of it. I can any how most conscientiously say, that no previously formed conjecture warped my judgment. As I have described, so did I actually |30| observe the facts. On some of the large patches of perpetual snow, I found the famous red snow of the arctic regions. I send with this letter my observations and a piece of paper on which I tried to dry some specimens. I also send a small bottle with two Lizards: one of them is viviparous, as you will see by the accompanying notice. M. Gay, a French naturalist, has already published in one of the newspapers of this country a similar statement, and probably has forwarded to Paris some account* |31| In the box there are two bags of seeds, one ticketed “valleys of Cordilleras five thousand to ten thousand feet high”: the soil and climate exceedingly dry; soil light and strong; extremes in temperature: the other “chiefly from the dry sandy traversia of Mendoza, three *

The following is an Extract from the Newspaper referred to by Mr Darwin: “Besides these labours I employed myself during the great rains in dissecting various reptiles. It must be interesting to know the influence of the climate of Valdivia on the animals of this family. In the greater part of those which I have been able to submit to my scalpel, I have found a truly extraordinary fact, that they were viviparous. Not only the innocent Snake of Valdivia has offered to my notice this singular phenomenon, but also a beautiful and new kind of Iguana which approaches very near to the Liposoma of Spix, [Johann Baptist von Spix (1781–1826), German naturalist who travelled in Brazil.] and to which, on account of its beautiful colours, he has given the name of Chrysosaurus. All the species, even those which lay eggs in Santiago, here produce their young alive; and the same thing happens with some Batrachians, and particularly with a genus near to the Rhinella of Fitzingen, [Fitzinger 1826.] of which the numerous species have the skin pleasingly spotted with green, yellow, and black. I need not dwell on the importance of this last example, in reference to comparative anatomy: an importance which appeared to me still greater when, on analyzing a Tadpole not yet transformed, I satisfied myself that nature has not varied her plan of organization. In these, as in the Tadpoles which live in water, the intestines were of a length very disproportioned to the body: now if this length were necessary to the latter, which live upon vegetable substances, it was altogether useless to those which are to undergo their metamorphosis in the belly of the mother: and thus nature has followed the march prescribed to her by a uniformity of construction, and without deviating from it, has admitted a simple exception, a real hiatus, well worthy the attention of the philosophical naturalist.” [See Gay 1836.]

14

[1835]. [Extracts from letters addressed to Professor Henslow]

thousand feet, more or less.” If some of the bushes should grow, but not be healthy, try a slight sprinkling of salt and saltpetre. The plain is saliferous. In the Mendoza bag, there are seeds or berries of what appears to be a small potatoe plant with a whitish flower. They grow many leagues from where any habitation could ever have existed, owing to the absence of water. Amongst the Chonos dried plants, you will see a fine specimen of the wild potatoe, growing under a most opposite climate, and unquestionably a true wild potatoe. It must be a distinct species from that of the lower Cordilleras.

1

These letters were read, without CD’s knowledge, at a meeting of the Cambridge Philosophical Society, 16 November 1835 with the president, William Clark, in the chair. CD had no opportunity of correcting this and it contains numerous misprints. Adam Sedgwick (1785–1873), Woodwardian Professor of geology, Cambridge University, 1818–73, reported on these letters, though without quoting CD in: Sedgwick. 1836. Geological notes made during a survey of the east and west coasts of S. America, in the years 1832, 1833, 1834 and 1835, with an account of a transverse section of the Cordilleras of the Andes between Valparaiso and Mendoza. [Read 18 November 1835] Proceedings of the Geological Society 2: 210–212. Entomological extracts from the pamphlet were published in: Extracts of letters from C. Darwin, Esq., to Professor Henslow. Printed for private distribution. Entomological Magazine 3, No. V, Art. XLIII (1836): 457–460. See Freeman 1977 and CCD1. 2 John Stevens Henslow (1796–1861), Cambridge clergyman, mineralogist and professor of botany since 1825. He became CD’s scientific mentor when at Cambridge and received and preserved CD’s Beagle specimens during the voyage. 3 Sao Tiago. 4 Charles Lyell (1797–1875), Scottish geologist and later friend of CD’s. His work was perhaps more influential for CD than that of any other single writer. 5 A cup-coral. 6 Misprint for Abrolhos archipelago, rocky islands off the coast of Brazil, north of Rio de Janeiro. 7 North of Rio de Janeiro. 8 Bory de Saint-Vincent 1822–31. 9 Friedrich Heinrich Alexander von Humboldt (1769–1859), German naturalist and traveller. 10 Flatworms. 11 Cyanobacteria, a type of blue green algae. 12 The genus of South American rodents which includes guinea pigs. 13 Two genera of extinct giant ground sloths. 14 An order of placental mammals that includes anteaters, armadillos and sloths. 15 William Sharp Macleay (1792–1865), naturalist and diplomat who devised the quinary system of classification. Macleay 1819–21. 16 See Rachootin 1982. 17 A kind of subterranean lizard possessing only front legs. 18 Venomous snakes, including copperheads and water moccasins. 19 Rattlesnakes. 20 Old World venomous snakes. 21 John Milton (1608–74), poet. Paradise lost 4. 799–800. CD recalled in his Autobiography (p. 85): ‘Formerly Milton’s Paradise Lost had been my chief favourite, and in my excursions during the voyage of the Beagle, when I could take only a single small volume, I always chose Milton.’ 22 A genus of bryozoans; marine leaf-like colonial animals. 23 A genus of transparent, marine animals of the Tunicata. 24 A free-swimming larval stage of crustaceans. 25 Zoology notes, p. 83, ‘Erichthus was the term formerly applied to a larval mantis shrimp of order Stomatopoda.’ See specimen 485 in ibid., p. 116. (DO)

1836. A letter, containing remarks on the moral state of Tahiti, New Zealand, &c. 26 27 28 29 30 31 32 33 34 35

36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52

15

An order of crustaceans which includes crayfish, crabs, lobsters, prawns and shrimp. A genus of brachiopods which includes many fossil and some living species. A fossil section of a crinoid stem. See Morris and Sharpe 1846. (DO) Maldonado. Later identified as Macrauchenia in Fossil Mammalia. A rabbit-sized South American rodent of the genus Dasyprocta. Phillip Parker King (1793–1856), commander of the Adventure, accompanying the Beagle, on the first surveying expedition to South America, 1826–30, and author of King 1839. See Darwin 1837, F1643. (p. 31) ‘A mountain chain or ridge, one of a series of parallel ridges; in pl. applied originally by the Spaniards to the parallel chains of the Andes in South America (las Cordilleras de los Andes), subsequently extended to the continuation of the same system through Central America and Mexico.’ (OED) Sessile hydroid that forms feathery colonies sometimes resembling ferns. Jean Vincent Felix Lamouroux (1779–1825), French naturalist. Lamouroux 1821. Jean Baptiste Pierre Antoine de Monet, Chevalier de Lamarck (1744–1829), French naturalist and transmutationist. Georges Cuvier (1769–1832), French systematist, comparative anatomist and palaeontologist. Carl Linnaeus (1707–78), Swedish botanist, physician, zoologist and taxonomist who introduced the binomial system of biological nomenclature. Marie-Jules-César Lelorgne de Savigny (1777–1851), French naturalist who accompanied Napoleon’s expedition to Egypt studying invertebrates, 1798–1802. John Narbrough (also spelled Narborough) (c.1640–88), naval commander. Narborough 1694. A stag beetle. Stephens 1833. Claude Gay (1800–73), French naturalist and traveller who studied the flora and fauna of Chile. Gay 1833. Acorn barnacles. Later the subject of CD’s Living Cirripedia 2 (1854). Concholepas: a clam. The barnacle specimen, later named by CD Cryptophialus minutus, is described in Living Cirripedia 2: 566. Uspallata Pass across the Chilean Andes between Mendoza, Argentina and Santiago de Chile. It reaches 3810 m (122 500 ft) above sea level. Peuquenes range, the Western range of the Cordillera mountains between Chile and Argentina. Fossil, oysterlike shells. Dark acid granitic glass. ‘Mr. Robert Brown has been kind enough to examine the wood: he says it is coniferous, and that it partakes of the character of the Araucarian tribe (to which the common South Chilian pine belongs), but with some curious points of affinity with the yew.’ Journal of researches, p. 406, and South America, p. 202.

1836. A letter, containing remarks on the moral state of Tahiti, New Zealand, &c. By Capt. R. FitzRoy and C. Darwin, Esq. of H. M. S. ‘Beagle.’ South African Christian Recorder 2, no. 4 (September): 221–38. F16401 A very short stay at the Cape of Good Hope is sufficient to convince even a passing stranger, that a strong feeling against the Missionaries in South Africa is there very prevalent. From what cause a feeling so much to be lamented has arisen, is probably well known to residents at the Cape. We can only notice the fact: and feel sorrow. Having lately visited some of the principal islands in the Pacific, and passed time enough in Australia to become acquainted with the opinions of some of the first men in that country

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1836. A letter, containing remarks on the moral state of Tahiti, New Zealand, &c.

respecting Missionaries, and the Missionary system, we were wholly unprepared for such notions as those so predominant in Cape Town. Before requesting a few minutes’ attention to some facts connected with this subject,—let me ask, whether the ideas expressed in the two following extracts from the works of Sir James Mackintosh, are not of higher value than the hastily formed opinions,—I would hardly say prejudices,—of people who think but little? Speaking of England, Sir James says, “Our scanty information relating to the earliest period of Saxon rule leaves it as dark as it is horrible. But Christianity brought with it some mitigation. “The arrival of Augustine in Kent, with forty other missionaries, sent by Gregory the Great to convert the Saxons, is described in picturesque and affecting language, by Bede, the venerable historian of the Anglo-Saxon Church. “It cannot be doubted that the appearance of men who exposed themselves to a cruel death for the sake of teaching truth, and inspiring benevolence, could not have been altogether without effect, even among the most faithless and ruthless barbarians. Liberty of preaching what they conscientiously believed to be Divine truth, was the only boon for which they prayed.” Again Sir James says, “Let those who consider any tribes of men as irreclaimable barbarians, call to mind that the Danes and Saxons, of whose cruelties a small specimen has been given, were the progenitors of those who, in Scandinavia, in Normandy, in Britain, and in America, are now among the most industrious, intelligent, orderly, and humane, of the dwellers upon earth.”2 If it is said that the races of men above mentioned always surpassed the Hottentots, the Bushmen, or the Caffers, in natural abilities and disposition, I will ask, are there any tribes of savages in the world, in a state more degraded than those just named? I presume the answer will be “yes, the New-Hollanders, and the natives of Terra del Fuego.” |222| Yet some of those most degraded of human beings, four natives of Terra del Fuego,3 were carried to England in the Beagle; were placed under the care of a schoolmaster, in whose house they lived, (one excepted) and there learned to speak English, to use common tools, to plant, and to sow. They were taught the simpler religious truths and duties; and the younger two were beginning to make progress in reading and writing when the time arrived for their return to their own country. I landed them among their people, by whom they were well received, but very soon plundered of most of the treasures their numerous friends in England had given to them. No dulness of apprehension was shewn by those natives—quite the reverse. The dispositions of all, especially the younger ones, were so good, although with failings inseparable from a thorough-bred savage, that it was hard to believe that, in the latitude of 54 degrees south, they once went naked, destitute of any covering, except a small piece of seal skin, worn only upon their shoulders; that they had devoured their enemies slain in battle; or that they had smothered, and afterwards eaten, the oldest women of their own tribe, when hard pressed by hunger during a severe winter! Surely, if three years sufficed to change the natures of such cannibal wretches as Fuegians, and transform them into well behaved, civilized people, who were very much liked by their

1836. A letter, containing remarks on the moral state of Tahiti, New Zealand, &c.

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English friends, there is some cause for thinking that a savage is not irreclaimable, until advanced in life; however repugnant to our ideas have been his early habits. Humboldt says,— “If, in the great and useful establishment of the American missions, those improvements were gradually made, which have been demanded by several bishops; if, instead of recruiting missionaries at hazard in the Spanish convents, young ecclesiastics were prepared for these functions in seminaries or colleges of missions founded in America, the military expeditions which I propose would become useless. Even those Indians, who, proud of their independence and their separate state, refuse to suffer themselves to be governed by the sound of the bell, receive with pleasure the visit of a neighbouring missionary. By leaving the Indians to enjoy more of the fruits of their labors, and by governing them less,—that is, by not shackling every instant their natural liberty,—the missionaries would see the sphere of their activity, which ought to be that of civilization, rapidly increase. Monastic establishments have diffused in the equinoctial part of the New World, as in the north of Europe, the first germs of social life. They still form a vast zone around the European possessions; and, whatever abuses may have crept into institutions, where all |223| power is confounded in one, they would be with difficulty replaced by others, which, without producing more serious inconveniences, would be as little chargeable, and as well adapted to the silent phlegm of the natives. I shall recur again to these settlements, the political importance of which is not sufficiently understood in Europe. It will be sufficient here to observe that expeditions of discovery, accompanied by an armed force, would be useless, were the government and the bishops to employ themselves seriously in the melioration of the missions. The progress of the missionaries would become rapid, if (after the example of the Jesuits) extraordinary succours were assigned to the most distant missions; and if the most intelligent and courageous ecclesiastics, and those best versed in the Indian languages, were placed in the most advanced posts. In both Americas the missionaries arrive every where first, because they find facilities which are wanting to every other traveller. ‘You boast of your journeys beyond Lake Superior,’ said an Indian of Canada to some fur-traders of the United States; ‘you forget, then, that the black coats passed it long before you; and that it was they who showed you the way to the west?’”4 But who can hear, or read of the wonderful exertions and effects of missionary zeal in South America, without admitting their important utility? Very many parts of that extensive continent are now almost unknown, and inhabited only by savages; which, before the expulsion of the Jesuits, were the seats of flourishing establishments of Indians, at the least semi-civilized, increasing, and improving yearly. Yet in how few years had the missionaries effected so much! Southey5 informs us that the first six Jesuits who set foot in the New World, landed at Bahia de todos Santos, in April, 1549. “Most distinguished among them was Manoel de

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1836. A letter, containing remarks on the moral state of Tahiti, New Zealand, &c.

Nobrega, the Apostle of Brazil, contemporary of the illustrious Xavier, and his rival in disinterested exertions for the good of his fellow-creatures. The obstacles they had to encounter in the works of civilization were most formidable, but their zeal and assiduity rose with the difficulty of the enterprise, and the most salutary effects resulted from their exertions. They began by teaching the native children the Portuguese language, and thus, while they fitted them to become interpreters, were also learning the Indian tongue. The greatest obstacle they had to surmount arose from the cannibal propensities of the natives. In feasts of this horrid description, their pride, their religion, their greatest luxury, were all implicated. The missionaries resolved to try to conquer this diabolical habit; but though they succeeded in putting down drunkenness—in healing |224| intestine feuds—in making a man content with one wife; the delight of feasting on the flesh of their enemies was too great to be relinquished; this propensity they could not overcome!!” A remarkable characteristic of the zealous spirit of those earlier American missionaries was their “entirely gratuitous performance of every religious ceremony.” “Nobrega had a school near the city of Bahia, where he instructed the native children—the orphans sent from Portugal—and the children of mixed breed. Reading, writing, and arithmetic were taught them; they learned to assist at mass, and to sing the church service. Frequently they went in procession through the town. The singing had a great effect, for the natives were passionately fond of music. When on an expedition to a strange, and perhaps hostile tribe, Nobrega took with him a few of the little choristers. At approaching an inhabited place, one of them carried the crucifix, in advance, the others followed singing the litany. Every where the savages received him so joyfully, that Nobrega began to think that the story of Orpheus, however exaggerated, had a better foundation than that of a fable. The pleasure of learning to sing was such a temptation, that the little children sometimes ran away from their parents to put themselves under the care of the Jesuits. Nobrega died in the fifty-third year of his age, prematurely worn out by a life of incessant fatigue, consequent on unexampled exertion, and heroic virtue. The day before his death, he took leave of all his friends, as if he were about to undertake a long journey. ‘They asked him where he was going?’ He replied, ‘Home! to my own country!’”6 Quitting opinions, and the tale of other times, it may be desirable to see what has been doing at Otaheite (now called Tahiti,) and at New Zealand, towards reclaiming the ‘barbarians.’ That epithet is, however, inapplicable to the natives of Otaheite, who were semi-civilized when discovered by Wallis,7 in 1765. The Beagle passed a part of last November at Otaheite or Tahiti. A more orderly, quiet, inoffensive community I have not seen in any other part of the world. Every one of the Tahitians appeared anxious to oblige, and naturally good tempered and cheerful. They showed great respect for, and a thorough good will towards, the missionaries (of the London Missionary Society); and most deserving of such a feeling did those persons appear

1836. A letter, containing remarks on the moral state of Tahiti, New Zealand, &c.

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to be, with whom I had the sincere pleasure of making acquaintance,—Messrs Pritchard, Nott, and Wilson.8 The missionary body have a considerable influence over the Queen of the Society Islands, as well as over her council, being considered the wisest men, and the truest friends, whom the natives of Tahiti can consult; but the Queen9 and the Chiefs are far |225| from allowing any approach to dictation, or authority, on the part of any foreigner; they are tenacious of their own honor and independence; and only yield to advice when their reason is sufficiently convinced of its propriety. To detail all that occurred, during even our short visit, tending to shew the beneficial effects of missionary exertion in that distant island, would occupy too much of your time; I will only copy a few of the notes which are in our journals, (Mr. Darwin’s and my own,) taking them as they occur—without alteration—believing that, in their original language, the feelings excited at the time will be shewn better than by an abridgment. Monday, 16th Nov. 1835. At Tahiti.—The Beagle was scarcely secured at her anchorage, before a number of canoes had assembled around her. All could not get alongside—but those whose outriggers obliged them to keep at a distance, contained natives who appeared to be as happy, and as civilly-disposed, as those who patiently waited by the ship’s side until leave was given for them to come on board. The necessary work being completed, permission was given, and in a few minutes our deck was thronged by men and boys. No women appeared. Every one was more or less clothed, excepting a few little boys. D.*—I suppose the number of natives on board the Beagle could not have been less than two hundred. It was the opinion of every one, that it would have been difficult to have selected an equal number of the lower order of any other nation, who would have given so little trouble, or behaved so well. Mr. Darwin and I landed among a mob of amusing, merry souls, most of them women and children. Mr. Wilson,10 a missionary who came out in the ship Duff more than thirty years ago, was at the landing place, and welcomed us to his house. The free, cheerful manners of the natives, who gathered about the door, and unceremoniously took possession of vacant seats, either on chairs or on the floor, shewed that they were at home with their instructor, and that churlish seclusion, or affected distance, formed no part of his system. Two chiefs walked into the room; they shook hands, sat down, and conversed familiarly with Mr. and Mrs. Wilson, in quite an European manner. They were cleanly, and, for the climate, well dressed. Their appearance and manners were prepossessing, and totally different from those of savages. A proof that the missionary influence is not paramount, I may copy from Mr. Darwin’s journal,—“A very unbecoming custom is now almost general. The natives cut their hair so closely, that |226| the heads appear shaven like those of monks, who leave only a small circle of hair. The missionaries have tried to persuade the people to change this habit, but they say ‘it is the fashion:’ a definite answer at Tahiti, as well as at Paris.

*

N. B. The letter D. prefixed, denotes an extract from the Journal of Mr. Darwin.

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1836. A letter, containing remarks on the moral state of Tahiti, New Zealand, &c.

19th November.—Walking towards the house of Mr. Nott, I saw an elderly native writing, in his cottage, and apparently very intent upon his employment. I asked to see what engaged his attention. It was a Tahitian version of the book of Jeremiah, written by Mr. Nott, which he was copying in a good distinct hand. Mr. Nott, the senior missionary upon the island, has almost completed a great work,—the translation of the Old Testament.11 18th November.— D.-Suspended, as it were, on the mountain side, there were glimpses into the dark depths of vallies; and at the highest pinnacles of the central mountains, which, ascending to within sixty degrees of the zenith, hid nearly half the sky. It was a sublime spectacle to watch the shades of night gradually covering the highest summits. Before we laid ourselves down to sleep, the elder Tahitian fell on his knees, and repeated a long prayer. He seemed to pray as a christian should, with fitting reverence to his God, without ostentatious piety, or fear of ridicule. 19th.D. At daylight, after their morning prayer, my companions prepared an excellent breakfast of bananas and fish. Neither of them would taste food without saying a short grace. Those travellers, who hint that a Tahitian prays only when the eyes of the missionary are fixed on him, might have profited by similar evidence. D.—About two years ago, although the use of the Ava* was prohibited, drunkenness, from the introduction of ardent spirits, became very prevalent. The missionaries prevailed on a few good men, who saw their countrymen rapidly working their own ruin, to join with them in a Temperance Society. From good sense and shame, the Queen, and all the chiefs, were at last induced to become members. A law was then immediately passed prohibiting the importation, or sale, of any kind of spirit. With remarkable justice, a certain period was allowed for the sale of stock in hand; but on an appointed day a general search for spirits took place, from which even the closets or trunks of the missionaries were not exempted. D. —When one reflects on the effects of intemperance on the aboriginals of both Americas, one may estimate the gratitude due from the Tahitians to their missionary counsellors. 20th.—Conversing with a Mr. Middleton12 about the Low Islands, |227| (those coral islands extending eastward from near Tahiti to beyond the Gambier group,)13 among which he has spent much time, I was much struck by the personal dislike and jealousy shown by him, when alluding to the missionaries themselves; and by the strong terms in which he mentioned the good effects of their intercourse with the Low Islanders; and how much more missionaries were required. His own words, as I have them in a paper written by himself, are: “The inhabitants of those Islands are now familiarized to Europeans, and are becoming partly civilized, owing to the gospel having been preached to them by the missionaries.” In another place he says,—“On this island there are inhabitants enough to require the constant residence of two missionaries.”† His own antipathy to the individuals, has arisen, I find, from personal differences. * †

Obtained from a native root. From Tahiti, many natives have gone, as missionaries, to other Islands. Of late years, the natives have opened the way for the European teachers. By their united influence and unabated exertion, Christianity, and consequent civilization, is spreading rapidly amongst the natives of Polynesia.

1836. A letter, containing remarks on the moral state of Tahiti, New Zealand, &c.

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At the door of a house I saw the owner reading a book attentively. It was the New Testament. I shall not easily forget the expression of that man’s countenance, as he read aloud, thinking himself alone. To my mind, such a sight tells more than any descriptions. 21st.—One of the officers slept in a house inhabited by a large family of the middling class of Tahitians. He told me that before sleeping the oldest man said prayers; one of the young men read a short portion of the New Testament; and then a hymn was sung by the whole family. I am informed that this was no more than the general custom in Tahitian families. 22nd, Sunday.—A party of us went to Papiete; others to Mr. Nott’s church.14 Those who could not go far from the ship attended Mr. Wilson’s Sabbath meeting, to see the natives at divine service. At Mr. Pritchard’s church in Papiete, we found an orderly, attentive, and decently-dressed congregation. I saw nothing grotesque, nothing ludicrous, (as some late voyagers have seen); nor any thing which had a tendency to depress the spirits, or disappoint expectation. The church was quite full; many were sitting outside. I suppose six hundred people were present, besides children. The fluent delivery of Mr. Pritchard, while preaching in the Tahitian language, surprised, and very much pleased us. Two of them were making notes of the sermon upon paper. A few were inattentive, but very few, compared with the number present. |228| It was evident the children had not been treated with harshness, for they clustered about their minister so closely, that he could not move without pushing them aside. D.—Mr. Pritchard was regularly educated at the Mission College. He appears to be a sensible, agreeable gentleman, and a good man. I have already mentioned Mr. Wilson with respect. Mr. Nott, the senior missionary whom we have seen, has resided forty years on the island. His occupations are now chiefly literary. He bears a very high character. I have said this much of these three persons, because the character of those who labour in the cause to which they are devoted, has been so often attacked. D.—One of my impressions which I took from Beechey15 and Kotzebue,16 was entirely wrong. I thought that the Tahitians had become a gloomy race, and lived in fear of the missionaries. Of the latter feeling I saw no trace. As to discontent, it would be difficult to pick out of an European crowd so many happy, merry faces. D.—On the whole, it is my opinion that the state of morality and religion in Tahiti is highly creditable. Perhaps those who attack the missionaries, their system, and the effects produced, do not compare the present state of things with that of twenty years ago, nor even with that of Europe at the present day. Looking only to the high standard of gospel perfection, they seem to expect that the missionaries shall effect what the apostles themselves failed in doing. In proportion as the state of things seems to be short of their high and ideal standard, the missionaries are blamed. Credit due for what has been effected, is not allowed. It appears to be forgotten by those persons, that human sacrifices,—the bloodiest warfare,—parricide,—and infanticide,— the power of an idolatrous priesthood,—and a system of profligacy unparalleled in the annals of the world,—have been abolished,—and that dishonesty, licentiousness, and

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1836. A letter, containing remarks on the moral state of Tahiti, New Zealand, &c.

intemperance have been greatly reduced, by the introduction of Christianity. In a voyager it is base ingratitude to forget these things. At the point of shipwreck, how earnestly he will hope that the lesson of the missionary has extended to the place on which he expects to be cast away! 25th, Wednesday.—At day-light this morning I went to Mr. Wilson’s school-house, now used also as a chapel, the old church at Matavi* having been blown down by a violent gale of wind. |229| (On each Wednesday morning a short service is performed in each of the Tahitian Churches.) This morning a hymn was sung, an extempore prayer followed, and then another hymn. The congregation was numerous and very attentive. I noticed that all the principal men of the district were present. Mr. Wilson’s manner pleased me much. It was the sincere and naturally impressive manner of a kind-hearted, honest man, earnestly performing a sacred duty. The Queen, and a large party, passed some hours on board the Beagle. Their behaviour was extremely correct, and their manners were inoffensive. Judging from former accounts, and what we witnessed, I should think that they are improving yearly; and that the conduct of the missionaries, and their families, has an influence over them exceeding that of a very differently disposed people by whom, unfortunately, they are often visited. Thursday, 26th.—At daylight this morning some of our party went to the school at Papiete. As we had heard of ‘compulsion’ and ‘unwilling attendance,’ I went early without having said a word to any one which could lead them to expect a visitor. In and about the large church, I found groups of elderly, and even old, people sitting together helping each other to read. While one read, the other listened; and if able, corrected him. One man, with spectacles, not less than sixty years of age, was learning to read! Some came in, others went out, just as they chose. During about an hour after sun-rise, these elderly people were instructing one another in this manner, previous to beginning their daily employment. Meanwhile in the school-house, a number of children (about ninety) were occupied in reading aloud, writing on slates, or answering questions, in the usual manner of infant schools. Mr. Pritchard asked me to desire them to write a sentence. I said ‘the captain wishes you much happiness.’ Mr. Pritchard having interpreted, they wrote his words instantly, and some of their own accord, added, ‘and we wish happiness to the captain.’ The hand-writing of many, indeed most of the elder girls and boys, was very good. The questions they answered readily; and though apparently in good discipline, a merrier, or more cheerful looking set of children I never saw. Returning by way of the (Tahitian) church, I saw Hitote, and several other chiefs, engaged in eager discussion. Mr. Pritchard and I went in. “You are come just in time,” said they, “We are disputing about the lightning conductors on board the Beagle; and cannot determine whether they end in the ship’s hold, or whether they go through her bottom into the water.” Mr. |230| Pritchard interpreted to me, and I tried to give them an explanation. *

Mr. Pritchard lives at Papiete, near the Queen’s usual abode. Matavi is the name of the village in which Mr. Wilson lives, about eight miles from Papiete.

1836. A letter, containing remarks on the moral state of Tahiti, New Zealand, &c.

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As to the morality of these islanders, and especially that of the women, which, though reprobated by some, has been defended by no less authorities than Cook17 and Turnbull,18 I would scarcely venture to give a general opinion, after only so short an acquaintance; but I may say that I witnessed no improprieties, neither did I see anything that would not incline me to suppose that their habits of morality are better than those of many civilized nations. It appears to me that the missionaries have succeeded in carrying attention to religion, and general morality, to a pitch at which it can hardly be maintained in future years, when intercourse with other countries will undermine their influence. Human nature in Tahiti cannot be supposed superior to erring human nature in other parts of the world. With respect to those who have severely censured the interference and effects of the missionary system,—I subscribe entirely to the following remark of Mr. Darwin: D.—I do believe that, disappointed in not finding the field of licentiousness so open as formerly, and as was expected, they will not give credit to a morality which they do not wish to practise, nor to the effects of a religion which is undervalued, if not quite despised. Is it not a striking fact, and one which ought to be recorded to the lasting honor of missionaries, that, owing to their example and influence, a Nation has solemnly rejected the use of ardent spirits? New Zealand 21st December.—In a conspicuous, solitary position, an English-looking house, without a building, or indeed any object except a flag staff, near it, presented a remarkable contrast to the fortified villages of the natives, and impressed one’s mind with a conviction of the great influence already obtained over the wild cannibals of New Zealand. In that lonely house lives the British Resident,19 his sole defence our national flag; his interpreters, and only supporters, the missionaries of the Church of England. From the anchorage, in the Bay of Islands, the view is very pleasing. One of the most conspicuous objects is the new church, now building by voluntary contributions. |231| 22nd.—I walked with Mr. Baker20 (missionary) about the little village of Paihia. Mr. Henry Williams,21 who was formerly a lieutenant in the navy, was absent on an exploring and negotiating expedition to the southern parts of the island. I much regretted having missed seeing him. He is considered the leading person among the missionary body in New Zealand; and is said by every one, who speaks of him, to be most thoroughly devoted to the great cause, in which he was one of the first, and most daring. Afterwards we went to Kororadika a village at the side of the harbour opposite to Paihia. The new church, before mentioned, is a slightly built edifice of bricks, with an abundance of bad glass windows. Placing a church at the head quarters of iniquity, at such a notorious place as Kororadika, is certainly a bold trial. Notwithstanding the ill-will entertained towards the missionaries by our spirit-selling countrymen, and by the evilly-disposed of the native population, not a pane of glass has been broken, nor has the slightest impediment been offered.

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1836. A letter, containing remarks on the moral state of Tahiti, New Zealand, &c.

In a long list of subscribers to the building, I saw the names of many masters of merchant ships and whalers, placed before very considerable sums. D.—This little village (Kororadika) is the very strong hold of vice. Although many tribes, in other parts, have embraced christianity, here the greater part of the people are still heathens. By them the missionaries are held in no esteem; but their conduct is inoffensive compared with that of our own countrymen. Strange as it appears, I have heard the missionaries say, that the only protection they now need, or on which they securely rely, is that of the native chiefs; and that too against their own countrymen,—English settlers. 23rd.—With Mr. Baker I went to Tapuna, the place where the first missionaries, Mr. King and Mr. Kendal22 established themselves in 1813. Mr. King was absent. His son told me that he was travelling amongst the natives. He was on horseback, the son said, but quite alone. Mrs. King described the former state of things which she witnessed herself, in very strong terms. She could not look back to those days without a shudder. Many times they were told that ‘before morning their house would be in flames,’ and that ‘stones were heating in the ovens in which they were to be cooked.’ But Mr. King found a trusty friend in a well-known chief named Waripoaki, and to him he always sent for assistance. Returning, we landed upon an island lately purchased by two Englishmen, not long ago masters of whale ships. The verbal attacks upon the missionaries made by these men, their illiberal |232| aspersions of Mr. Busby’s* character, and their own manners, and disgusting conversation, prevented our remaining many minutes in their company. Such men as these,—strongly prejudiced, deaf to reason, and often habitually vicious,—run-away convicts, whose characters may be imagined,—and democratic, untractable natives, cause the principal difficulties against which honest, upright settlers, and the whole missionary body, have to contend. 24th.—I went with Mr. Baker to a native village at some distance, called Cawa-cawa. It was pleasant to witness the cordial greetings which passed between Mr. Baker and the natives whom we occasionally met. He had been asked by them to visit their village in order to settle some disputes which had arisen between their neighbours and themselves. He also wished to gain advocates for the abolition of the use of spirits. By temporising, talking to both parties, and inducing each to go half way, Mr. Baker succeeded in amicably settling the disputed affairs. Is it not gratifying to find that even in this savage country the missionaries are appealed to, and act as mediators and peacemakers? In our return I went a little way out of the path to look at two oxen, lately imported. Near the door-way of a house, in a retired place, a sick woman was reading a book. It was a copy of the Gospel of St. Matthew, printed at Paihia, in the New Zealand language.23 Now there could have been no affectation nor hypocrisy in the occupation of that woman; her being seen was quite accidental and unexpected.

*

The British Resident.

1836. A letter, containing remarks on the moral state of Tahiti, New Zealand, &c.

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Enquiring about her afterwards, I found that she was one of a long list of invalids, who depend upon the mission for advice and medicine. Mr. Baker told me that one of the most troublesome, though gratifying duties of the Missionaries, is that of acting, or attempting to act, as medical men. No regular practitioner having as yet established himself in the land, every complaint is entrusted to their attention and good will, but slight medical knowledge. How necessary it must be for a missionary to have some knowledge of medicine and surgery! The successful wanderings of the Jesuit Faulkner24 would be a sufficient demonstration, if numerous other instances were wanting. Owing to his skill in medicine, Faulkner was enabled to be a solitary instance of a white man living many years in safety among various tribes of wandering South American Indians. 28th.—I went to Waimate, the settlement lately formed by the Mission, with the view of introducing agriculture, and the mechanical arts, among the natives. The thoroughly English appearance |233| of three well designed, respectable houses, surrounded by gardens, out-houses, and well cultivated fields, was surprising and delightful. About twenty acres of land seemed to be worked. Corn was in full ear, and looked well. I was received by a person whose intelligent, kind, and truly respectable demeanor at once excited a kindly feeling. This was Mr. Davis,25 the superintendant of the farming establishment. Mr. William Williams and Mr. Clarke,26 were absent, having gone to the opposite side of the island to attend the funeral of a young missionary of the Wesleyan persuasion. In the gardens all English vegetables seemed to thrive. The farm yard was thoroughly English. A large barn, built entirely by natives, under Mr. Davis’s directions; a blacksmith’s shop and forge; English carts and farming implements, successively engaged attention. In the barn two natives were thrashing corn; another native was attending to the winnowing machine. A mill, and mill-dam, entirely the work of the natives, were next examined. They were good works of their kind, and would have been interesting, independent of their locality. Mr. Davis told me that when the mill was finished and first put in action, nothing could exceed the surprise and delight of the natives, especially those who had assisted in the work. They called it ‘a ship of the land!’ ‘wonderful white men,’ said they, ‘fire, water, earth, and air, are made to work for them, by their wisdom!’ I was much struck by the harmony and apparent happiness of the three families of whose society I had too slight a glimpse. Instead of hours, I should have enjoyed passing days with them. An air of honesty, and that outward tranquillity which is the result of a clear conscience and inward peace, offered a forcible contrast to the alleged gloom, and even misanthropy, of which some missionaries have been accused by those persons whose own habits, or associates, made them perhaps most undesirable acquaintances for an English family. It was very satisfactory to mark the lively interest taken by them in every detail connected with the Fuegians. Again and again they recurred to the subject. Their anxiety also about the state of other South American Savages, and about other islands in the Pacific, gave me a high opinion of their true missionary spirit. It was striking to find all the members of this isolated society so anxious to hear about and to talk of Fuegians, and other distant tribes of

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1836. A letter, containing remarks on the moral state of Tahiti, New Zealand, &c.

savages, rather than to draw attention to their own doings,—to their troubles, their success, or their wants. Speaking of the agricultural settlement at Waimate,—Mr. Darwin says, “All this is very surprising, when it is considered |234| that three years ago nothing but fern was seen on the place now occupied by houses, gardens, and corn fields.” D.— Moreover, native workmen effected this change. The lesson of the missionary has acted like an enchanter’s wand. Houses have been built, windows framed and glazed; fields ploughed, and even trees grafted by New Zealanders. At the mill, a native is seen, powdered over with flour, like his brother millers elsewhere. When I considered this whole scene, I thought it admirable; not only because England was vividly brought to mind; nor solely because of the triumphant feeling excited by seeing such effects of English energy and devotion to a good cause; but chiefly because of the moral effect it must have upon the natives. D.—The young men and boys employed about the houses seemed to be very merry and good humoured. In the evening, they were playing at cricket with the sons of the missionaries. The young women who attended in the houses had a tidy, healthy look, very different from that of the women about the villages of Kororadika and Paihia. D.—Late in the evening I went to Mr. W. William’s house, where I passed the night. I found there a large party of children (of the missionaries) assembled to pass Christmas day together. They were sitting round a table at tea; a nicer, or more merry group, I never saw. (To think that this sight was in the land of cannibalism, and all atrocity!) The cordiality and happiness so plainly visible in the faces of the young ones, seemed to be equally prevalent among the older persons of the mission. D.—When I took leave of these families, it was with thankfulness for their kind welcome, and with feelings of high respect for their evidently superior characters. I think it would be difficult to find men better adapted to discharge the duties of their important office. D.—As far as I can understand, the greater proportion of the inhabitants of the northern parts of the Island profess Christianity. It is curious, that the religion of the others has been altered, and is now partly Christian and partly heathen. Moreover, the outward conduct of the unbelievers is said to be improving, in consequence of the general spread of some of the Christian doctrines. How far those who profess Christianity are sincere, I have had no opportunity of judging. Mr. Busby, the British Resident, mentioned a pleasing fact: One of his young men, who had been accustomed to read prayers to the rest of the servants, left him. Some weeks afterwards, |235| happening to pass, late in the evening, by an out-house, he saw and heard another of his men reading the bible, with difficulty, and by the light of the fire, to the rest of his companions. Afterwards they knelt down and prayed. In their prayers they mentioned Mr. Busby, and his family, and each of the missionaries. Dec. 30th.—By all accounts the New Zealanders are improving yearly; so are the natives of other islands which have been visited by missionaries. Those islanders who have been

1836. A letter, containing remarks on the moral state of Tahiti, New Zealand, &c.

27

visited only by whalers, or purveyors for Chinese epicures, have in no way profited. On the contrary, they have learned to shew less respect to their own ordinances, and have learned no better ones. The most abandoned, profligate habits and ideas have been taught, or encouraged, by their visitors. Fire-arms, ammunition, and spirits, have been exchanged for provisions, and for women. Escaped convicts have done very great harm in the Pacific. Unrestrained by any principle, those abandoned men have been the springs of excessive injuries. The murder of the missionaries at the Friendly Islands was caused by the dark and revengeful intrigues of a convict who had escaped to those Islands from Sydney. Judging from all I have heard on the spot, and since, I should think it difficult to form any moderate estimate of the tumultuous anarchy, and destruction of human life, which has been prevented during the last twenty years by the presence and active exertions of missionaries. Without estimating the ships of other nations, under the colors of the United States, and of our own country, more than five hundred sail of vessels have been annually employed in the Pacific during late years. For refreshments and supplies, only those islands can, with safety, be now frequented, on which either European or native missionaries have established themselves. When a merchant ship approaches a remote island in the Pacific, her first object is to ascertain whether it has ever been visited by a missionary. If it has, she knows she may approach with confidence; if it has not, she keeps under sail in the offing, and if she does communicate with the shore, it is with the utmost caution, and with much reluctance. But even while profiting by the influence of the missionaries, and even assisted by them in intercourse with the natives, many persons have not hesitated to ridicule the means by which the missionary has gained that very influence by which they are profiting; and, in direct opposition to his entreaties, or well-known wishes, encourage the natives in immorality, and in the use of spirits. Moreover, they abuse, and seek for faults in a system, and in the conduct of individuals, which has a tendency to check, or |236| expose, the impropriety of their own hitherto unrestrained immorality. If the opponents of missionaries, and of the missionary system, allow no other good character to have been earned in the Pacific, by those hard working men, never can they be deprived of that of Peace-makers. Surrounded by those who are engaged in commerce, annually increasing; unavoidably involved in local dissensions; referred to on all occasions as interpreters or mediators, and, I may say, as the consular agents of white men of all nations; does it not argue very favourably for the missionaries, that, although sneered at by nominal friends, censured by enemies, and always struggling against opposition, they have as yet upheld the character of their sacred office? Speaking of them as consular agents is, because they now attend to most of the local affairs between natives and foreigners, which would employ the time of a consul, where national agents are established. At Tahiti there is, nominally, a British Consul; but

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1836. A letter, containing remarks on the moral state of Tahiti, New Zealand, &c.

he lives at the Sandwich Islands! and might as well be at Kamschatka! At New Zealand there is a British Resident;—an anomalous appointment destitute of authority, yet ostensibly important. In those places the greater part of the duties to which our government expect their agents to attend, are, in fact executed by the missionaries, not by choice, but because, as Christian men, they cannot tamely withdraw from difficulty, and deny that assistance which they are able to give, although they see those in official situations set the example of the Lévite in the Parable. After reading these statements, it will not be difficult to form an idea of the secular embarrassments which perplex the South Sea missionaries; after having overcome the primary dangers and difficulties of first establishing themselves among hostile and cannibal savages, yet, although they are now able to assist their own countrymen, who have eagerly profited by their exertions, and are now settling in every direction upon those very lands to which access was attained by their hardy, daring enthusiasm, their own strength is failing! Embarrassments of many kinds are arising. One is a mean jealousy of that very influence, which has enabled those who are jealous, to approach the place where they now revile those to whom they owe gratitude for enabling them to be there. While their assistance was wanted, no praise of the missionaries was too warm for the adventurers to bestow, who were seeking a settlement. But when once established, and a knowledge of the language attained, “Why should Mr. —— have more influence over the natives than I?” is too frequent a thought. A few respectable settlers, such as Mr. Clindon, Mr. Bicknell, Mr. Main, and Mr. Henry,27 have acted in a very different way: in the most honorable, and truly English manner. But for their support, |237| the few, almost isolated missionaries, would have to contend alone against a host of reprobates. To me it appears that the steady support, and respectable countenance of those upholders of the true character of Britons, has, in a quiet, unpretending manner, assisted in a very great degree the progress of incipient civilization and Christianity. By those who dislike the natural influence of the Missionaries, an outcry has been raised against their alleged attempts to ‘monopolize the land.’ Say those men—“Why should a missionary be allowed to purchase so much land as to prevent those who come after him from obtaining an eligible piece of ground near a frequented part?” or,—“Why should Mr. —— be allowed to prevent Waripoaki and his tribe from selling me that piece of ground, because he thinks that I shall sell spirits, or build a public-house?” “Have not,” (say they) “Have not the missionaries already monopolized the best lands, in the finest situations?” Now, lest it should be thought that undue advantage had been taken by any members, or by the whole of the missionary body, it ought to be here explained that a large extent of land was long ago purchased in New Zealand, by the ‘Church Missionary Society’; and that it is not, as supposed by some, the private property of individuals. Other lands from time to time have been purchased by individuals of the missions, for the future maintenance of their families.

1836. A letter, containing remarks on the moral state of Tahiti, New Zealand, &c.

29

And what else could those do who have divided that tie which held them to a country which could not be their children’s home? Around them are a group of little ones, who will acknowledge New Zealand to be their country and their home. Shall the missionaries be debarred from endeavoring to make that home acceptable to those children, and from providing for their future maintenance? If a missionary, and a recent settler, are each in treaty for a particular piece of ground, and the former obtains it upon easier terms than the latter, in consequence of the good-will of the natives, is it not a natural and legitimate advantage earned in the fairest and the most honourable manner? Many of the natives understand and appreciate the motives of the missionaries, and are, moreover, personally attached to their little children, whom they like to consider as belonging to their country. If anathemas, indulgences, or excommunications were resorted to by protestant missionaries, one might have a suspicion of undue influence, but as such engines of power have not emanated from a British mission, may we not take it for granted that the influence of missionaries appointed by the Church of England or London Missionary Societies, is not undue? |238| The facts, in their simplicity, are these:—As opportunities offered, the missionaries, always upon the spot, and watching their opportunity, have bought lands upon terms more advantageous than those which could be obtained by visitors or recent settlers, strangers to the natives. Owing to the same natural advantages,—those of local acquaintance, and being always near at hand,—the missionaries have selected the best lands they could afford to purchase. Ought they to have taken the worst? After all, the property (that island in New Zealand) of the Church Missionary Society, and of individuals of the missions, taken together, does not bear a larger proportion to New Zealand than the country of Rutland does to Great Britain and Ireland! Is there then no room left for settlers? With a remark or two applicable to all missionaries, this letter, already long,—though not too long for such a subject,—shall be concluded. In the Pacific, not a single avowed disagreement, or misunderstanding, has yet taken place between officers of government and missionaries, but there are plain signs of an increasing and mutual approach towards a kind of jealousy which cannot too soon be prevented. When authorized agents of government assume active functions in newly-settled, or recently civilized countries, is it not time for the political agency of the missionary to cease? His work, as connected with affairs of policy, or government, is done, and the crowning proof that so great a point in civilization has been gained, in consequence of his energetic exertions, is the appointment of such an officer. From that time ought not the missionary to separate himself from secular affairs? Should he not reflect, that however he may have been called upon to act during former emergencies, the special duties of his sacred calling ought to be separated from politics, or any kind of hostilities or dissensions.

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1836. A letter, containing remarks on the moral state of Tahiti, New Zealand, &c.

Excepting as peace-maker, his voice should not be heard, neither should his influence be exerted in other than offices of religion and education,—while the authorized officer, or agent of government, can be referred to in secular affairs. Robt. FitzRoy. On the whole, balancing all that we have heard, and all that we ourselves have seen concerning the missionaries in the Pacific, we are very much satisfied that they thoroughly deserve the warmest support not only of individuals, but of the British Government. Robt. FitzRoy. Charles Darwin. At Sea, 28th June, 1836.

1

2 3

4 5 6 7 8

9 10 11 12 13 14 15 16 17 18 19 20 21

This is CD’s first intentional publication, written between Cape Town and St Helena, as proposed by Jody Herschel. Fitz-Roy to Herschel 29 June 1836 (Royal Society, Herschel Letters, 7 (E-F). Most of his contributions are prefixed ‘D.’ CD’s contributions are not always verbatim from his original Beagle diary. See CCD1: 499. Mackintosh 1830, pp. 32, 60. Yokcushlu, known as Fuegia Basket (?1821–?1883), of the Alakaluf tribe from the western islands of Tierra del Fuego. Boat Memory (c.1810–30), Alakaluf man from Tierra del Fuego. See Narrative Appendix. El’leparu, known as York Minster, (?1804–c. 1871), Alikhoolip man named after an islet near Cape Horn Island. Orundellico, known as James ‘Jemmy’ Button, (?1816–63). Humboldt and Bonpland 1814–29, 5: 578–80. Southey 1810–19, 1: 232. Ibid., pp. 267 ff. Samuel Wallis (1728–95), who first visited Tahiti in 1767. See Wilson 1806 and Robertson 1948. George Pritchard (1796–1883), missionary at Papiete in Tahiti and British Consul in Tahiti, 1837–44. Henry Nott (1774–1844), of the London Missionary Society, arrived in Tahiti in 1797. Wilson, missionary at Matavai in Tahiti since 1797. Aimatta, known as Pomare IV (1827–77), Queen of Tahiti. Charles Wilson (1770–1857), missionary at Matavai in Tahiti since 1797. Nott 1838. John Middleton. See Narrative 2: 516. Mangareva: small group of islands located at the southeast terminus of the Tuamotu archipelago in the South Pacific. Depicted in Narrative 2: facing p. 517. Beechey 1831. Kotzebue 1821. James Cook (1728–79), naval captain, explorer, navigator and marine surveyor. Turnbull 1813. James Busby (1801–71). Charles Baker (1803–75), of the Christian Missionary Society. Henry Williams (1792–1867), of the Christian Missionary Society.

1837. [Notes on Rhea americana and Rhea darwinii] 22 23 24 25 26 27

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John King, the first missionary of the Church Missionary Society in New Zealand, arrived 1810. Thomas Kendall (1778–1832). Parts of the New Testament translated into Maori by William Williams and printed by William Colenso were available from early 1836. Falkner 1774. Richard Davis (1790–1863), missionary. CD called him ‘Davies’ in Journal of researches, pp. 507, 509–10. Charles Oliver Bond Davis (1816–87), Maori interpreter and writer. William Williams (1800–78), missionary who translated the Bible into Maori. George Clarke (1798–1875), a missionary. Henry Bicknell (1766–1820), Edward Main (b. 1773), William Henry (1770–1859), all of the London Missionary Society.

1837. [Notes on Rhea americana and Rhea darwinii]. [Read 14 March] Proceedings of the Zoological Society of London 5 (51): 35–6. F1643 Mr. Darwin then read some notes upon the Rhea Americana, and upon the newly described species,1 but principally referring to the former. This bird abounds over the plains of Northern Patagonia and the United Provinces of La Plata; and though fleet in its paces and shy in its nature, it yet falls an easy prey to the hunters, who confound it by approaching on horseback in a semicircle. When pursued it generally prefers running against the wind, expanding its wings to the full extent. It is not generally known that the Rhea is in the habit of swimming, but on two occasions Mr. Darwin witnessed their |36| crossing the Santa Cruz river, where its course was about 400 yards wide and the stream rapid. They make but slow progress, their necks are extended slightly forwards, but little of the body appears above water. At Bahia Blanca, in the months of October and September, an extraordinary number of eggs are found all over the country. The eggs either lie scattered about, or are collected together in a shallow excavation or nest; in the former case they are never hatched, and are termed by the Spaniards Huachos. The Gauchos unanimously affirm that the male bird alone hatches the eggs, and for some time afterwards accompanies the young. Mr. Darwin does not doubt the accuracy of this fact, and states that the cock bird sits so closely that he has almost ridden over one in the nest. Mr. Darwin has also been positively informed that several females lay in one nest, and although the fact at first appears strange, he considers the cause sufficiently obvious, for as the number of eggs varies from 20 to 50, and, according to Azara,2 even 70 or 80, if each hen were obliged to hatch her own before the last was laid, the first probably would have been addled; but if each laid a few eggs at successive periods in different nests, and several hens, as is stated to be the case, combine together, then the eggs in one collection would be nearly of the same age. Mr. Burchell3 mentions that in Africa two females are believed to lay in one nest. Mr. Darwin then proceeds to notice the other species of Rhea, which he first heard described by the Gauchos, at River Negro, in Northern Patagonia, as a very rare bird, under the name of Avestruz Petise. The eggs were smaller than those of the common Rhea, of more elongated form, and with a tinge of pale blue. This species is tolerably abundant about a degree and a half south of the Rio Negro, and the specimen presented to the Society was

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1837. Observations of proofs of recent elevation on the coast of Chili

shot by Mr. Martens4 at Port Desire in Patagonia, (in latitude 48). It does not expand its wings when running at full speed, and Mr. Darwin learned from a Patagonian Indian that the nest contains fifteen eggs, which are deposited by more than one female. It is stated in conclusion that the Rhea Americana inhabits the country of La Plata as far as little south of the Rio Negro, in lat. 41°, and that the Petise takes its place in Southern Patagonia.

1

2 3 4

Named by Gould Rhea darwinii, however it had already been named Rhea pennata by Orbigny [1834]–47, 2: 67 note 2 [now called Pterocnemia pennata (Orbigny, 1834)]. This report of CD’s notes followed Gould’s original description Gould 1837a. Félix d’ Azara (1746–1811), Spanish explorer and army officer who surveyed Spanish and Portuguese territories in South America. Azara 1802–5. William John Burchell (1781–1863), explorer and naturalist. Burchell 1822, 1: 280. Conrad Martens (1801–78), draughtsman on the Beagle 1833–4.

1837. [Remarks upon the habits of the genera Geospiza, Camarhynchus, Cactornis and Certhidea of Gould]. [Read 10 May] Proceedings of the Zoological Society of London 5 (53): 49. F1644 The group of groundfinches,1 characterised, at a previous meeting, by Mr. Gould,2 under the generic appellations of Geospiza, Camarhynchus, Certhidea, and Cactornis, were upon the table; and Mr. Darwin being present, remarked that these birds were exclusively confined to the Gallapagos Islands; but their general resemblance in character, and the circumstance of their indiscriminately associating in large flocks, rendered it almost impossible to study the habits of particular species. In common with nearly all the birds of these islands, they were so tame that the use of the fowling-piece in procuring specimens was quite unnecessary. They appeared to subsist on seeds, deposited on the ground in great abundance by a rich annual crop of herbage.

1

2

Now famously known as ‘Darwin’s finches’, a term coined by P. R. Lowe in 1935. See Lowe 1936. The title for this item is taken from the contents list, p. iv. Gould exhibited specimens on 10 May. There are four other papers by Gould on CD’s South American birds in part 5. John Gould (1804–81), ornithologist; taxidermist to the Zoological Society of London. He described CD’s Beagle bird specimens in Birds. The characterisations from the previous meeting are in Gould 1837b.

1837. Observations of proofs of recent elevation on the coast of Chili, made during the survey of His Majesty’s Ship Beagle commanded by Capt. FitzRoy R. N. By Charles Darwin, Esq., F.G.S. [Read 4 January] Proceedings of the Geological Society of London 2: 446–9. F1645 The subject of recent elevations on the coast of Chili being, in the opinion of many, still open to discussion, Mr. Darwin gives, in this memoir, the results of his own observations. The

1837. Observations of proofs of recent elevation on the coast of Chili

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portion of the coast, more particularly examined by the author, extends from the river Rapel, about sixty miles south of Valparaiso, to Conchali, about eighty miles north of it. Close to the mouth of the Rapel, dead barnacles occur adhering to rocks three or four feet above the highest tidal level; and in the neighbouring country recent marine shells are scattered abundantly to the height of about 100 feet. Ten miles to the north, and at an equal distance from the sea, is the village of Bucalemu, in the neighbourhood of which are very extensive beds of recent shells. At the bottom of the great valley of Maypo, and some miles from the coast, marine shells of existing species are also numerous; and at St. Antonio, |447| near the northern point of that river, are large quarries of shells. Between this point and Valparaiso in the ravine, Quebrada Onda, the remains of a species of shell common on the coast, were noticed by the author. Along the bold granitic coast south of the promontory which forms the bay of Valparaiso, are numerous level and horizontal beds of shells, constituting an almost continuous band, elevated from 60 to 230 feet above the level of the sea. The shells are brittle, but of various kinds, and are all similar and in similar proportional numbers to those on the beach. They are mingled with some earth, though packed closely together, and overlie a partially consolidated breccia of granitic fragments which rests on the solid rock. After a careful examination of these deposits, first by himself, and afterwards with Mr. Alison,1 guarded by a recent inspection of the heaps of shells accumulated by the natives in Tierra del Fuego, Mr. Darwin was convinced that the shelly beds near Valparaiso, were formed when the sea occupied a different level. The following are the principal circumstances which lead to this conviction. The great number of the shells forming extensive, horizontal beds, whereas the heaps in Tierra del Fuego collected by the inhabitants, always retain a conical figure: their position, at the extremities of headlands inaccessible from the sea, and unfit for strongholds, being without fresh water: the large proportional number of extremely small shells: and lastly, their brittle and decayed condition, the state of decomposition having an evident relation to the comparative heights at which the shells were lying. Comminuted shells were noticed by Mr. Darwin at the heights of 560 and 1300 feet, but the evidence of their having been part of a beach was not convincing. At San Lorenzo in the bay of Callao, Mr. Darwin traced a similar process of decay from perfect shells in the lowest beds to a mere layer of calcareous powder in the highest. This phenomenon, he adds, can be observed only in countries where rain never falls. On the north side of the bay of Valparaiso, near the Viña del Mar, is an abundance of elevated shells. Mr. Alison, by climbing a point of rock about fourteen feet above high water, and removing the dung of sea fowls, discovered Balani adhering to the stone. With respect to the historical evidence of the earthquake of 1822, Mr. Darwin says that he met with no intelligent person who doubted the rise of the land, or with any of the lower order who doubted that the sea had fallen. He mentions also the altered position of the wreck and of the rock in the bay; and from a part of the fort being invisible from a point on the land before the earthquake, but visible afterwards, he infers that the movement of the land was unequal.2 A further proof of change, obtained for the author by Mr. Alison, is shown by the remains of a sea-wall built in 1680, and over which, up to 1817, the sea broke during the

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1837. Observations of proofs of recent elevation on the coast of Chili

northerly gales. Mr. John Martin, a ship carpenter of Valparaiso, remembers walking in 1819 on the beach at the foot of this wall, and he has been frequently obliged to climb up to the street to avoid the sea. This wall is now separated from the bay by two rows of houses, but a portion of what |448| appeared to be its base, carefully levelled by a resident engineer, was found to be 11 feet 6 inches above high water mark. Mr. Darwin does not ascribe the whole of this change to the earthquake of 1822, and is of opinion that the alteration then produced was under three feet. The church of San Augustin is believed to have been built in 1634, and the base of its walls is 19 feet 6 inches above high tide level; but there is a tradition that the sea formerly approached very close to its foundations. Allowing, therefore, 4 feet 6 inches for its protection when built, the amount of change in 220 years is only 15 feet. The granite rocks which form the coast are also water-worn and hollowed at about the same height, namely, 14 feet above the present sea level. These data, Mr. Darwin is of opinion, prove, that though the changes in 220 years have been small, yet that they were preceded by a period of comparative rest, during which there was time for any former marks on the rocks to become obliterated. The author then described the beds of recent shells between Concon and Quintero, about 100 feet above the sea level; the deposits near Plazilla and Catapilco; and in the valley of Longotomo. On the hills to the north of the latter, about 200 feet above the sea, immense quantities of recent shells coat the surface or the sides of the ravines; and hence Mr. Darwin infers that the action of the sea determined the minor inequalities of the land. Similar deposits, more or less abounding in shells, were noticed by him near Guachen, and in the valley of Quilimap. Close to Conchali, on the south side of the bay, are two very distinct terrace-like plains, the lower being about sixty feet high. Mr. Darwin then gave a very brief notice respecting the marine origin of the terraces at Coquimbo, described by Capt. Basil Hall3 and discussed by Mr. Lyell. The proofs of the origin assigned to them rest on the occurrence of recent shells in a friable calcareous rock elevated 250 feet above the sea. This calcareous stratum passes downwards into a shelly mass chiefly composed of fragments of Balanideæ, and this again overlies a sandstone abounding with silicified bones of gigantic sharks mingled with extinct species of oysters and Pernæ4 of a great size[.] The intermediate bed contains some shells in common with the upper, in which all are recent, and with the lowest in which the greater number are extinct. The phenomena of the parallel terraces and the elevated shells occur in a strongly marked manner in the villages of Guasco and Copiapo, the latter being 350 miles to the north of Valparaiso: recent shells also occur at different elevations at an equal distance to the south of it at Concepcion and Imperial. Mr. Darwin believes that the land on the coast of Chili has risen, though insensibly, since 1822. In the Island of Chiloe he is fully convinced, from oral testimony and the state of the coast, that a change effected imperceptibly is now in progress. In support of this gradual rise, independent of earthquakes, he states, that the eastern coast of South America, bordering the Atlantic from the Rio Plata to the Strait of Magellan, presents terraces containing recent shells; yet in the provinces near the mouth of the Plata, earthquakes are never experienced; and it is impossible to suppose that the most violent of the Chilian earthquakes |449| could produce these effects, as the shocks

1837. A sketch of the deposits containing extinct Mammalia

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are scarcely transmitted to the plains at the western foot of the Cordilleras. Hence, he concludes, that the earthquakes, volcanic eruptions, and sudden elevations on the coast line of the Pacific, ought to be considered as irregularities of action in some more widely extended phenomenon.

1 2

3 4

Robert Edward Alison, English author and resident of Valparaiso and later managing director of a Chilean mining company who wrote on South American affairs. A note by the editors reads ‘In the following page a part of the fort previously invisible is stated to have become visible; but this apparent discrepancy arises from the observations alluded to by Mr. Caldcleugh having been made from the shipping, and those by Mr. Darwin from a point on the land.’ Basil Hall (1788–1844), naval captain and geographer. Hall 1824. Oysterlike clams.

1837. A sketch of the deposits containing extinct Mammalia in the neighbourhood of the Plata. By Charles Darwin, Esq., F.G.S. [Read 3 May] Proceedings of the Geological Society of London 2: 542–44. F1646 Mr. Darwin premised his account of the geological features of the district in which the remains of the Toxodon, described at the meeting on the 19th of April by Mr. Owen,1 (p. 541) were found, by remarking that as the other mammalia and the fossil shells had not yet been accurately examined, the notice was necessarily imperfect. To the westward and southward of the great estuary of La Plata, extend those level and almost boundless plains which are known by the name of the Pampas. Their geological constitution over many hundred square miles does not vary. It consists of a reddish argillaceous earth, which generally contains irregular concretions of a white aluminous limestone, or indurated marl, often passing irregularly into a compact calcareous stone, traversed by small linear cavities, similar to those which occur in many of the freshwater limestones of Europe. In the province of Entre Rios, the formation which composes the surface of the Pampas overlies and passes into a series of beds of sand, clay, and crystalline cellular limestone; containing sharks’ teeth, gigantic oysters, and other shells belonging to the genera arca, Venus and pecten. These shells, with the exception of the oyster, have a general resemblance to existing species. To the northward and eastward of the Plata, the province of Banda Oriental, though very low and level, consists of gneiss, granite and primary slate. These rocks are generally concealed by a considerable thickness of a reddish earth, which, though at first sight like ordinary detritus, belongs to the same formation with that composing the Pampas. This deposit, extending over so wide an area on both sides of the Plata, abounds with very numerous remains of various extinct mammalia; among which the Toxodon, Megatherium, Mastodon, an animal covered with an armadillo-like case, and as Mr. Darwin believes, the horse, co-existed in the same district. Proofs of the elevation of the land within a recent period, occur in several parts. Mr. Darwin stated that he had seen in the possession of Sir W. Parish,2 marine shells

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1837. A sketch of the deposits containing extinct Mammalia

which occur near Buenos Ayres in great beds, elevated several yards above the level of the river; and these same species the author had found living on the mud banks on another part of the coast. He, therefore, inferred, that at no very remote period a great bay occupied the area both of the Pampas and the lower parts of Banda Oriental; and that into this bay the several rivers, which now unite to form the Plata, poured down reddish sediment, resulting, as at the present day, from the decomposition of the granites of Brazil, and charged with carbonate and sulphate of lime, perhaps derived from the Cordillera. On the cliff-formed shores of Entre Rios, the line can be distinguished where the estuary mud first encroached on the deposits of the ocean. The author also supposed that the ancient rivers, like those of the present day, carried down the carcases of land animals, which thus became entombed in the accumulating sediment. Since that period, by the gradual rising of the land, the bottom of the great bay has been converted into plains, almost as level as the surface of the former sea; and the |544| rivers now hollowing out courses for themselves, have exposed, in many places, the skeletons of those ancient inhabitants of the neighbouring land. Mr. Darwin then briefly alluded to a small formation of mud and shingle at Bahia Blanca, some hundred miles south of the Plata, in which the remains of several extinct quadrupeds have been discovered. Amongst these he enumerated the Megatherium Cuvieri, the remains perhaps of a smaller species of Megatherium; a quadruped closely allied to the armadilloes, but nearly as large as a horse; some small rodents, and other animals. These remains are embedded with one species of terrestrial, and several of marine shells, the latter being identical with some existing in the adjoining bay. It is, therefore, certain that the greater number of the above mammalia found at Bahia Blanca lived within a very recent epoch; and from the position of the bed in which they occur, it is equally certain that the form of the land has undergone, since that period, very little change, even of level, with respect to the ocean. Several hundred miles further southward, Mr. Darwin found the remains of an animal which Mr. Owen says has an affinity with the Llama or Guanaco, but was of a gigantic size: this animal likewise existed since the Atlantic has been peopled by the shells now living.3 The author observed in conclusion, that the comparative recentness of the epoch at which the fossil mammalia lived, is shown, first by the shells associated with them; secondly, by the recent tertiary character of the strata underlying the deposit containing these remains; and thirdly, from the little altitude of such beds above the level of the sea; for in this country, according to the author’s observations, the movements seem to have been so regular, that the amount of elevation becomes a measure of time. These facts relating to the former existence of the inhabitants of a part of the globe so remote from Europe, fully confirm the remarkable law, often insisted upon by Mr. Lyell, that “the longevity of the species”4 among mammalia has been of shorter duration than among molluscs. The author finally remarked, that although several gigantic land animals, which formerly swarmed in South America, have perished, yet that they are now represented by

1837. On certain areas of elevation and subsidence in the Pacific and Indian oceans

37

animals, confined to that country; and though of diminutive size, possess the peculiar anatomical structure of their great extinct prototypes.5

1 2 3 4 5

Richard Owen (1804–92), Hunterian Professor of comparative anatomy and physiology, 1836–56. He described CD’s fossil Beagle specimens in Fossil mammalia. Owen 1837. Woodbine Parish (1796–1882), British Chargé d’Affaires at Buenos Ayres. Later named Macrauchenia in Fossil Mammalia. Lyell 1830–3, 3: 48, 55. CD quoted the same passage in Journal of researches, p. 97. Called elsewhere by CD ‘The law of the succession of types’. See Journal of researches, pp. 210–12.

1837. On certain areas of elevation and subsidence in the Pacific and Indian oceans, as deduced from the study of coral formations. By Charles Darwin, Esq., F.G.S. [Read 31 May] Proceedings of the Geological Society of London 2: 552–54. F1647 The author commenced by observing on some of the most remarkable points in the structure of Lagoon islands. He then proceeded to show that the lamelliform corals, the only efficient agents in forming a reef, do not grow at any great depths; and that beyond twelve fathoms the bottom generally consists of calcareous sand, or of masses of dead coral rock. As long as Lagoon islands were considered the only difficulty to be solved, the belief that corals constructed their habitations (or speaking more correctly, their skeletons), on the crests of submarine craters, was both plausible and very ingenious; although the immense size, sinuous outline, and great number, must have startled any one who adopted this theory. Mr. Darwin remarked that a class of reefs which he calls “encircling” are quite, if not more, extraordinary. These form a ring round mountainous islands, at the distance of two and three miles from the shore; rising on the outside from a profoundly deep ocean, and separated from the land by a channel, frequently about 200 and sometimes 300 feet deep. This structure as observed by Balbi1 resembles a lagoon, or an atoll, surrounding another island. In this case it is impossible, on account of the nature of the central mass, to consider the reef as based on an external crater, or on any accumulation of sediment; for such reefs encircle the submarine prolongation of islands, as well as the islands themselves. Of this case New Caledonia presents an extraordinary instance, the double line of reef extending 140 miles beyond the island. Again the Barrier reef, running for nearly 1000 miles parallel to the North-East coast of Australia, and including a wide and deep arm of the sea, forms a third class, and is the grandest and most extraordinary coral formation in the world. The reef itself in the three classes, encircling, barrier and lagoon, is most closely similar; the difference entirely lying in the absence or presence of neighbouring land, and the relative position which the reefs bear to it. The author particularly points out one difficulty in understanding the structure in the barrier and encircling classes, namely, that the reef extends so far from the shore, that a line drawn perpendicularly from its outer edge down to the solid |553| rock on which the reef must be based, very far exceeds that small limit

38

1837. On certain areas of elevation and subsidence in the Pacific and Indian oceans

at which corals can grow. A distinct class of reefs however exists, which the author calls “fringing reefs,” which extend only so far from the shore, that there is no difficulty in understanding their growth. The theory which Mr. Darwin then offered, so as to include every kind of structure, is simply that as the land with the attached reefs subsides very gradually from the action of subterranean causes, the coral building polypi soon again raise their solid masses to the level of the water; but not so with the land: each inch lost is irreclaimably gone:—as the whole gradually sinks, the water gains foot by foot on the shore, till the last and highest peak is finally submerged. Before explaining this view in detail, the author offered some considerations on the probability of general subsidences,—such as the small portion of land in the Pacific, where many causes tend to its production, an argument first suggested by Mr. Lyell, and the extreme difficulty (with the knowledge that corals grow at but limited depths) in explaining the existence of a vast number of reefs on one level, without we grant subsidence, so that one mountain top should be submerged after another; the zoophytes always bringing up their stony masses to the surface of the water. Subsidence being thus rendered almost necessary, it was shown by the aid of sections, that a simple fringing reef would thus necessarily be converted by the upward growth of the coral into one of the encircling order, and this finally, by the disappearance through the agency of the same movement of the central land, into a lagoon island. In the same manner a reef skirting a shore would be changed into a barrier extending parallel to, but at some distance from, the mainland. Mr. Darwin then showed, that there existed every intermediate form between a simple well characterized encircling reef, and a lagoon island; that New Caledonia supplied a link between encircling and barrier reefs; that the different reefs produced by the same order of movement were always in juxtaposition, of which the Australian barrier associated with encircled islets and true lagoons, affords a good example. He then proceeded to show that within the lagoon of Keeling Island, proofs of subsidence might be deduced from many falling trees and a ruined storehouse; these movements appearing to take place at the period of bad earthquakes, which likewise affect Sumatra, 600 miles distant. It was thence inferred as probable, that as Sumatra rises, (of which proofs are well known to exist,) the other end of the lever sinks down; Keeling Island thus acting as an index of the movement of the bottom of the Indian Ocean. Again at Vanikoro,2 where the structure indicates according to the theory recent subsidence, violent earthquakes are known lately to have occurred. The author then removed an apparent objection to the theory, namely, that subsidence would form a disc of coral but not a cup-shaped mass or lagoon, by showing that the corals which grow in tranquil water are very different from those on the outside, and less effective; and that as the basin becomes shallower they are subject to various |554| causes of injury. The lagoon nevertheless is constantly filling up to the height of lowest water spring tides, (the utmost possible limit of living coral,) and in that state it long remains, for no means exist to complete the work. Mr. Darwin then proceeded to the main object of the paper, in showing that as continental elevations act over wide areas, so might we suppose continental subsidences would do, and in conformity to these views, that the Pacific and Indian seas could be divided into symmetrical areas of the two kinds; the one sinking, as deduced from

1837. [Note on an Australian insect.]

39

the presence of encircling and barrier reefs, and lagoon islands, and the other rising, as known from uplifted shells and corals, and skirting reefs. The absence of lagoon islands in certain wide tracts, such as in both the West and East Indies, Red Sea, &c., was thus easily explained, for proofs of recent elevation are there abundant. In a like manner, in very many cases where islands are only fringed with reefs, which according to the theory had not been subsiding, actual proofs of elevation were adduced. Mr. Darwin remarked that, excepting on the theory of the configuration of reefs being determined by the order of movement, the circumstance that certain classes which are characteristic and universal in some parts of the sea, being never found in others, is quite anomalous, and has never been attempted to be explained. Mr. Darwin then pointed out the above areas both in the Pacific and Indian Oceans, and deduced the following as the principal results. 1st. That linear spaces of great extent are undergoing movements of an astonishing uniformity, and that the bands of elevation and subsidence alternate. 2. From an extended examination, that the points of eruption all fall on the areas of elevation. The author insisted on the importance of this law, as thus affording some means of speculating, wherever volcanic rocks occur, on the changes of level even during ancient geological periods. 3. That certain coral formations acting as monuments over subsided land, the geographical distribution of organic beings (as consequent on geological changes as laid down by Mr. Lyell) is elucidated, by the discovery of former centres whence the germs could be disseminated. 4. That some degree of light might thus be thrown on the question, whether certain groups of living beings peculiar to small spots are the remnants of a former large population, or a new one springing into existence.3 Lastly, when beholding more than a hemisphere, divided into symmetrical areas, which within a limited period of time have undergone certain known movements, we obtain some insight into the system by which the crust of the globe is modified during the endless cycle of changes.

1 2 3

Balbi 1811, 9: 395–405. The subject of this paper culminated in Coral reefs. Solomon Islands, east of Guadalcanal. This is CD’s first published reference to his interest in the origin of species. Compare with the conclusion of Darwin 1837, F1646. (p. 35) See van Wyhe 2007.

1837. [Note on an Australian insect.] In Waterhouse, G.R., Descriptions of some new species of exotic insects. [Read 5 December 1836.] Transactions of the Entomological Society of London 2: 194. F2015 [Alleloplasis darwinii] This extraordinary insect was discovered by C. Darwin, Esq. whilst “sweeping in coarse grass and brushwood; King George’s Sound.” I have therefore named it after this gentleman, who has done so much towards the advancement of science, and to whom Entomology owes so much, since he has brought to this country an immense collection of insects from various parts of the world, and particularly of the minute species which had been comparatively neglected.

40

1838. On the connexion of certain volcanic phænomena

1838. On the connexion of certain volcanic phænomena, and on the formation of mountain-chains and volcanos, as the effects of continental elevations. By Charles Darwin, Esq., Sec. G. S. [Read 7 March] Proceedings of the Geological Society of London 2: 654–60. F16491 The author first gave a detailed account of the volcanic phænomena, which accompanied the earthquake that destroyed Concepcion on the morning of the 20th of February, 1835; and then deduced from volcanic phænomena, certain inferences with respect to the formation of mountain-chains, and continental elevations. In describing the phænomena of the earthquake of 1835, Mr. Darwin quotes the published accounts by Captain Fitzroy* and Mr. |655| Caldcleugh;† likewise communications received by him from Mr. Douglas,2 a resident on the island of Chiloe. A few days after the earthquake, several volcanos within the Cordilleras, to the north of Concepcion, though previously quiescent, were in great activity. It is doubtful, however, if the volcano of Antujo, in nearly the latitude of Concepcion, was affected, while the island of Juan Fernandez, 360 miles to the north-east of the city, was apparently more violently shaken than the opposite shore of the main land. Near Bacalao Head, a submarine volcano burst forth in sixty-nine fathoms water, and continued in action during the day as well as part of the following night. That island was also affected in a remarkable manner, by the earthquake which overthrew Concepcion in 1751. In Concepcion, the undulations of the surface appeared, to the inhabitants, to proceed from the south-west; and this direction was likewise inferred, from the effects observed in the buildings; for those walls, which had their extremities towards the point of disturbance, remained erect, though much fractured, whilst those (and the streets cross each other at right angles) which extended parallel to the line of the vibration, were hurled to the ground. This was strikingly exemplified in the cathedral, where the great buttresses of solid brick-work were cut off, as if by a chisel, and thrown down; while the wall, for the support of which they had been built, though much shattered, remained standing. In Chiloe, south of Concepcion, the shocks were very severe, but they entirely ceased in about eight minutes. The motion, as described by Mr. Douglas, was horizontal, and similar to that of a ship going before a high, regular swell; from three to five shocks being felt in a minute; and the direction being from N.E. to S.W. Forest-trees nearly touched the soil in these directions; and a pocket compass placed level on the ground vibrated, during the violent shocks, two points to westward, but only half a point to eastward; and during the minor shocks the needle pointed north. At Calbuco, a village on the mainland opposite the northern extremity of Chiloe, as well as at Valdivia, between Chiloe and Concepcion, the earthquake was much less severely felt; and near Mellipulli, in the Cordilleras (not far from Calbuco), not at all. The volcano of Villareca, near Valdivia, which is said to be more frequently in irruption than almost any other in the chain, was not the least affected; though * †

Journal of the Royal Geographical Society, vol. vi, p. 319, 1836. [FitzRoy 1836.] Phil. Trans., 1836; Part I. p. 21. [Alexander Caldcleugh (d. 1858), Scottish businessman, plant collector and author. Caldcleugh 1836.]

1838. On the connexion of certain volcanic phænomena

41

the volcanos of central Chili are stated by Mr. Caldcleugh to have been seen, some days afterwards, in great activity. Several of the culminating points of the Cordillera in front of the island of Chiloe, exhibited increased energy during the earthquake, and immediately after it. During the shocks, Osorno, which had been in activity for at least forty-eight hours previously, threw up a thick column of dark blue smoke; and directly it had passed away, a large crater was seen forming in the S.S.E. side of the mountain; Minchinmadiva also, which had been in its usual state of moderate activity, commenced a fresh period of |656| violence. At the time of the principal shock, the Corcovado was quiet; but when the summit of the mountain was visible a week afterwards, the snow had disappeared from the north-west crater. On Yntales, to the south of the Corcovado, three black patches, resembling craters, were observed above the snow-line after the earthquake, though they had not been noticed previously to it. During the remainder of the year, the whole of the volcanic chain, from Osorno to Yntales, a range of 150 miles, exhibited, at times, unusual activity. On the night of the 11th of November, Osorno and Corcovado threw up stones to a great height; and on the same day, Talcahuano, the port of Concepcion, 400 miles distant, was shaken by a very severe earthquake; and on the 5th of December the whole summit of Osorno fell in. After these details of more particular phænomena, Mr. Darwin alluded to the great areas over which earthquakes have been simultaneously felt; but he added, it is impossible even to guess through how wide an extent, in the subterranean regions, actual changes may have taken place. In order to enable the reader, who may be more familiar with European than South American geography, to comprehend the vast surface which was affected by the earthquake of February 1835, he stated, that it had a north and south range, equal in extent to the distance between the North Sea and the Mediterranean: that we must imagine the eastern coast of England to be permanently raised; and a train of volcanos to become active in the southern extremity of Norway; also that a submarine volcano burst forth near the northern extremity of Ireland; and that the long dormant volcanos of the Cantal and Auvergne, each sent up a column of smoke. The contemplation of volcanic phænomena in South America, has induced the author to infer, that the crust of the globe in Chili rests on a lake of molten stone, undergoing some slow but great change; for if this inference be denied, he says, the only alternative is, that channels from the various points of eruption must unite in some very deeply-seated focus. This conclusion, however, he doubts, on account of the union of the different trains of volcanos on the one line of the Cordillera, and more especially as many hundred square miles of surface in Chili, have been elevated during the same earthquake. Moreover, these elevations have acted within a period geologically recent, throughout the whole, or at least the greater part, of Chili and Peru, and have upraised the land several hundred feet. He is further of opinion, that the shocks coming from a given point of the compass, and the overthrow of the walls, according to their position with respect to this point, prove that the vibrations do not travel from a profound depth, but are due to the rending of the strata not far below the surface of the earth. In a geological point of view, the author conceives, the three classes of phænomena exhibited during this earthquake of February 1835, viz. a submarine outburst—renewed

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1838. On the connexion of certain volcanic phænomena

volcanic activity, simultaneously at distant localities—and a permanent elevation of the land, to be of the greatest importance, as forming parts of one great action, and |657| being the effects of one great cause, modified only by local circumstances. Mr. Darwin further observed, that, as the volcanos near Chiloe commenced, at the moment of the shock, a period of renewed activity, which lasted throughout the following year, the motive power of these volcanos (as well as of the submarine outburst near Juan Fernandez) must be of a similar nature with that, which, at the same instant, permanently raised another part of the coast; and he therefore concluded, that no theory of the cause of volcanos, which is not applicable to continental elevations, can be considered as well-grounded. Mr. Darwin then offered some remarks on the two tables published by Humboldt,3 of the great earthquakes which affected, in 1797 and 1811, so large portions of America; and he is of opinion, that a repetition of the coincidences can alone determine how far the increased activity of the subterranean powers, at such remote points, was the effect of some general law, or of accident. He likewise disbelieves that periodical eruptions, as those of Coseguina, in 1709 and 1809, or of earthquakes, as the shocks felt at Lima on the 17th of June 1578, and the 17th of June 1678, are more than accidental agreements. He also gave a table of the volcanic phænomena in South America in 1835; and concluded, that it is probable that the subterranean forces manifest, for a period, their action, beneath a large portion of the South American continent, in the same intermittent manner as they do beneath isolated volcanos. In the latter table, Mr. Darwin pointed out the case of Osorno, Aconcagua, and Coseguina, (the first and last being 2700 miles apart,) which burst into sudden activity early on the morning of June 20th, 1835; but he hesitated to assent to there being any necessary connexion between them. He further remarked, that if such simultaneous outbursts had been observed in Hecla and Ætna, points unconnected by any uniformity of physical structure, it would be doubtful how far they would have been worthy of consideration; but in South America, where the volcanic orifices fall on one line of uniform, physical structure, and where the whole country presents proofs of the action of subterranean forces, he conceives it ceases to be improbable, to any excessive degree, that the action of the volcanos should sometimes be absolutely simultaneous. The author then briefly described the groups into which the volcanic vents of the Cordilleras have been divided. The most southern extends from Yntales to the volcanos of central Chili, a distance of nearly 800 geographical miles; the second, from Arequipa to Patas, rather more than 600 miles; the third, from Riobamba to Popayan, a distance of about 300 miles; and to the northward, there are in Guatimala, Mexico, and California, three groups of volcanos separated from each other a few hundred miles. That the vents in each of these groups are connected, the author has little doubt; but that the groups are united in one system, there are less satisfactory means of proving. Mr. Darwin next considered the nature of the earthquakes which occur at irregular intervals on the South American coast. He is |658| perfectly convinced, from the numerous points of analogy which exist between these phænomena and simple eruptions, that they belong to the same class of events; but he makes this distinction, that earthquakes, unaccompanied by eruptions at the chief point of disturbance, are followed by a vast number of

1838. On the connexion of certain volcanic phænomena

43

minor shocks. These, he believes, indicate a repeated rending of the strata beneath the surface; whereas, in an ordinary eruption, a channel is formed during the first outburst. Among other phænomena belonging to earthquakes, Mr. Darwin alluded to their affecting elongated areas. Thus the shock in Syria, in 1837, was felt on a line 500 miles in length by 90 in breadth; and those in South America are felt along 800 and 1000 miles of coast, but are on no occasion transmitted across the Cordillera to a nearly equal distance; and, as a consequence, the inland towns are much less affected than those near the coast. He does not conceive, however, that the disturbances proceed from one point, but many ranged in a band, otherwise the linear extension of earthquakes would be unintelligible. For instance, in 1835, the island of Chiloe, the neighbourhood of Concepcion and Juan Fernandez were all violently affected at the same time. The last consideration which Mr. Darwin entered upon indicating the cause of earthquakes, is, that in South America they have been generally accompanied by elevation of the land; though it is not a necessary concomitant, at least to a perceptible amount. But he especially observed, that, as at Concepcion, during the few days succeeding the great shock, several hundred earthquakes, of no inconsiderable violence, were experienced, whilst the level of the ground in that part of the coast certainly was not raised by them (but after the interval of a few weeks, it stood lower,), there is a clear indication of some cause of disturbance, independent of the uplifting of the land in mass. In summing up the evidence of phænomena accompanying earthquakes, the author is of opinion that the following conclusions may be drawn:— 1st.

That the primary shock of an earthquake is caused by a violent rending of the strata, which, on the coast of Chili and Peru, seems generally to occur at the bottom of the neighbouring sea. 2ndly. That this is followed by many minor fractures, which, though extending upwards, do not, except in submarine volcanos, actually reach the surface. 3dly. That the area thus fissured extends parallel, or approximately so, to the neighbouring coast mountains. Lastly. That the earthquake relieves the subterranean force, precisely in the same manner as an eruption through an ordinary volcano. The author afterwards discussed the nature and phænomena of mountain chains; and stated his belief, that the injection, when in a fluid state, of the great mass of crystalline matter, of which the axis is generally composed, would relieve the subterranean pressure |659| in the same manner as an ejection of lava or scoria; and that the dislocation of the strata would produce horizontal vibrations through the surrounding country. In drawing this parallel, he also stated his belief, that the earthquake of Concepcion marked one step in the elevation of a mountain chain; and he adduced, in support of this opinion, the fact observed by Capt. Fitzroy, that the island of Santa Maria, situated 35 miles to the south-west of that city, was elevated to three times the height of the upraised coast near Concepcion; or at the southern extremity of the island, eight feet; in the middle, nine feet; and at the northern extremity, upwards of ten feet; and that at Tubal, to the south-east of Santa Maria, the land

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1838. On the connexion of certain volcanic phænomena

was raised six feet;* this unequal change of level indicating, in his opinion, an axis of elevation in the bottom of the sea, off the northern end of Santa Maria. Mr. Darwin then alluded to Mr. Hopkins’s Researches in Physical Geology,4 where it is demonstrated, that if an elongated area were elevated uniformly, it would crack or yield parallel to its longer axis; and that if the force acted unequally, transverse cracks or fissures would be produced, and that the masses, thus unequally disturbed, would represent the irregular outline of a mountain-chain. He further added, that if the force should act unequally beneath the area simultaneously affected, various fissures would be formed in different parts, having different directions, and thus give rise, at the same moment, to as many local earthquakes. The author believes, that this view will more readily explain intermediate districts being little disturbed (as Valdivia in 1835, and in cases alluded to by Humboldt,) than the supposed inertness of intermediary rock in conveying the vibrations from a deeply-seated focus. If the preceding theory of the cause of earthquakes be true, Mr. Darwin said, we might expect to find, that the many parallel ridges of which the Cordillera is composed, were of successive ages. In Central Chili, the only portion examined by him, this is the case, even with regard to the two main ridges; and some of the exterior lines of mountains appear, likewise, to be of subsequent dates to the central ones. The contemplation of these phænomena led him, while in South America, to infer, that mountain-chains are only subsidiary, and attendant operations on continental elevations. The conclusion, that mountain-chains are formed by a long succession of small movements, the author conceived may be arrived at by theoretical reasoning. The first effect of disturbing agents, Mr. Hopkins has shown, is to arch the crust of the earth, and to traverse it by a system of parallel but vertical fissures; and that subsequent elevations and subsidences of the disjointed masses would produce anticlinal and synclinal lines. In the Cordillera, the strata in the central parts, are inclined at an angle commonly exceeding 45°, and are very often absolutely vertical, the axis being composed of granitic masses, which, from the number of dikes branching from them, must have been fluid when propelled against the lower beds. How then, |660| he asked, could the strata have been placed in a highly inclined and often vertical position, by the action of the fluid rock beneath, without the very bowels of the earth gushing out? If, on the other hand, it be supposed that mountain-chains were formed by a succession of shocks similar to those which elevated Concepcion, and after long intervals, time would be allowed for the injected rock to become solid, as well as the upper part of the great central mass. Thus, by a succession of movements, the strata might be placed in any position; and the crystalline nucleus gradually thickening, would prevent the surface of the surrounding country, being inundated with molten matter. In crossing the Andes, Mr. Darwin was surprised at finding, not one great anticlinal line, but eight, or more; and that the rocks composing the axes were seldom visible, except in denuded patches in the vallies. This circumstance, he conceives, must be due to the thickness of the up-heaved strata being equal, or nearly so, to the average distance of the anticlinal *

Journal of the Royal Geographical Society, vol. vi. p. 327.

1838. [Notes on Cocos-Keeling Island plants]

45

from the synclinal lines. For in that case, the masses of strata, when placed vertically, would occupy, or rest on, as great an horizontal extent, as they did before they were disturbed. In the central ridges of the Cordillera, there are masses of compact, unstratified rocks, half again as lofty as Ætna; and these, he believes, for the reasons before stated, were formed by the gradual cooling of the subjacent fluid mass; afterwards slowly elevated to the present position, by the injection of molten matter at nearly as slow a rate, as we must suppose the innumerable layers of volcanic products, of which the Sicilian mountain is formed, have been ejected. In conclusion, Mr. Darwin repeated the argument, that mountain-chains and volcanos are due to the same cause, and may be considered as mere subsidiary phænomena, attendant on continental elevations;—that continental elevations, and the action of volcanos, are phænomena now in progress, caused by some slow but great change in the interior of the earth; and, therefore, that it might be anticipated, that the formation of mountain-chains is likewise in progress; and at a rate which may be judged of, by either actions, but most clearly by the growth of volcanos.

1 2 3 4

See the revised version of this paper published in the Transactions as Darwin 1840, F1656 (p. 97). Charles D. Douglas, surveyor and resident of Chiloé. Humboldt and Bonpland 1814–29, 4: 36. William Hopkins (1793–1866), mathematician and geologist. Hopkins 1838.

1838. [Notes on Cocos-Keeling Island plants]. In Henslow, J. S., Florula Keelingensis. An account of the native plants of the Keeling Islands. By the Rev. J. S. Henslow, M.A., Professor of Botany in the University of Cambridge. Annals of natural history 1 (July): 337–47. F19591 |339| 1. Paritium tiliaceum. “Common on one of the islands. It is exceedingly useful throughout the Pacific; and in Otaheite particularly, the bark is employed in the manufacture of cordage, whilst the light wood is used by the fishermen for floats. The natives readily procure fire from the wood by friction.” |340| 3. Pemphis acidula. “No sooner has a new reef become sufficiently elevated by the accumulation of sand upon its surface, but this plant is sure to be the first which takes possession of the soil.” 5. Guilandina Bonduc. “Grows only on one islet.” |341| 6. Acacia (Farnesiana ?) “On the same islet with the last.” 9. Boerhavia diffusa. |343| Var. β. “Grows upright and untidy, and is the commonest weed, growing everywhere.” Var. γ. “Grows close to the ground, and is abundant on one spot within ten or twelve yards of the sea, where it was pointed out to me as possessing an esculent root, and considered to be quite distinct from var. β.”

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1838. Copy of a memorial presented to the Chancellor of the Exchequer

11. Guettarda speciosa. “The flowers possess a delightful perfume.” 12. Cordia orientalis.—“The settlers have named this Keeling-teak, because it furnishes them with excellent timber. They have built themselves a vessel with it. A large tree, abounding in some of the islands, very leafy, with scarlet flowers; but only a few blossoms were expanded at the time, and they easily fell off.” 13. Tournefortia argentea.—“A moderate sized tree, with small white flowers, very common.” 15. Ochrosia parviflora. “Forms straight handsome trees, with smooth bark, which are commonly dispersed two or three together. The fruit is bright green, like that of the walnut.” 18. Lepturus repens.—“Occurs in salt places, in the interior of the islands.”

1

Only CD’s notes and the species names are reproduced here. Duncan M. Porter, in Beagle plants, p. 154 wrote of these notes: ‘Another list that has not surfaced is that prepared for Henslow [by CD] of the Cocos-Keeling Islands plants. Many of those enumerated in Henslow’s (1838) [i.e. the present paper] paper on Darwin’s collections have comments on them attributed to Darwin. … This information is not in the Plant Notes or the Zoological Diary, leading me to conclude that it must have been in a separate list, probably prepared after the Beagle returned to England.’ 240 words from CD’s original list are quoted by Henslow. The islands were named after their discoverer in 1609 Captain William Keeling. John Clunies Ross (1786–1854), Scottish Merchant navy captain, settled in these islands of the Indian Ocean for the first time in 1827 and established a cocoa-nut plantation. CD visited the islands in the Beagle 1–12 April 1836. These coral atolls with lagoons were an important influence on CD’s views on the origins of coral islands.

1838. Copy of a memorial presented to the Chancellor of the Exchequer [Thomas Spring Rice], recommending the purchase of fossil remains for the British Museum. Parliamentary Papers, Accounts and Papers 1837–1838, paper number (637), vol. XXXVI.307 (27 July): 1. F1944 Copy of Memorial presented to the Chancellor of the Exchequer,1 recommending the Purchase of Fossil Remains for the British Museum. (Mr. Warburton.)2 Ordered, by The House of Commons, to be Printed, 27 July 1838. 637. |1| Fossil Remains Return to an Order of the Honourable The House of Commons, dated 6 July 1838;—for, COPY of a Memorial presented to the Chancellor of the Exchequer, recommending the Purchase, by the Trustees of the British Museum, of the two Collections of Fossil Remains belonging to Mr. Mansell3 and Mr. Hawkins.4 Whitehall Treasury Chambers, 25 July 1838. F. Baring.5

1838. Copy of a memorial presented to the Chancellor of the Exchequer

47

To the Right Honourable the Chancellor of the Exchequer The Memorial of your Petitioners humbly Showeth, That your Petitioners have heard with great concern that a recent offer for sale to the British Museum, by Mr. Mansell and Mr. Hawkins, of two valuable collections, illustrating the geology of an important portion of England, has been declined, in consequence of the deficiency of the national revenue for the present year. That many of your Petitioners who are conversant with the subject have examined these collections, and consider them not only to be of peculiar value as demonstrating the subterraneous structure of this country, but also of general interest to the scientific world, as throwing new and important lights on many branches of research that are now conducted with unexampled activity in all countries, for the purpose of illustrating the physical history of the globe, and applying such knowledge also to the useful purposes of life. That with a view to the advancement of such objects, societies and museums have been established in nearly all the large provincial towns of this kingdom, and still more extensive museums provided at the national expense by all the Governments in the civilized world. And as your Petitioners would consider it to be conducive to the honour and scientific reputation of England if these collections were placed in the British Museum, so it would be, in their opinion, both detrimental to science and injurious to the honour of the nation if they were allowed to be broken up and dispersed by public sale, or purchased by any foreign Government. That the getting together of these collections has resulted from a concurrence of such rare opportunities and extraordinary qualifications in the individuals by whom they have been made, that if the occasion which now offers of securing to the nation the fruits of such rare coincidences be not made use of it must be lost for ever. And your Petitioners will ever pray, &c. (signed) Charles Darwin, Sec. of Geol. Socy.6 [The other 17 names are omitted.]

1 2 3

4

5 6

Thomas Spring Rice (1790–1866). This memorial was reprinted in Darwin 1839, F1945. Henry Warburton (1784–1858), MP for Bridport, 1826–41, President of the Geological Society, 1843–45. Gideon Algernon Mantell (1790–1852), physician, geologist and palaeontologist who collected invertebrate and dinosaur fossils. He was paid £4000 in 1838 for his collection. Thomas Hawkins (1810–89), palaeontological collector. Hawkins was paid £1800 in 1840 for his collection. He sold an earlier collection of saurian fossils to the Museum in 1834 for £1310. Francis Thornhill Baring (1796–1866), MP for Portsmouth, 1826–65 and Joint Secretary of the Treasury, 1835–39. CD became a member of the Geological Society of London on 2 November 1836 and was Secretary from 16 February 1838 to 19 February 1841. See CCD2.

48

1838. On the formation of mould

1838. On the formation of mould. By Charles Darwin, Esq., F.G.S. [Read 1 November 1837] Proceedings of the Geological Society of London 2: 574–76. F1648 The author commenced by remarking on two of the most striking characters by which the superficial layer of earth, or, as it is commonly called, vegetable mould, is distinguished. These are its nearly homogeneous nature, although overlying different kinds of subsoil, and the uniform fineness of its particles. The latter fact may be well observed in any gravelly country, where, although in a ploughed field, a large proportion of the soil consists of small stones, yet in old pastureland not a single pebble will be found within some inches of the surface. The author’s attention was called to this subject by Mr. Wedgwood,1 of Maer Hall, in Staffordshire, who showed him several fields, some of which, a few years before, had been covered with lime, and others with burnt marl and cinders. These substances, in every case, are now buried to the depth of some inches beneath the turf. Three fields were examined with care. The first consisted of good pasture land, which had been limed, without having been ploughed, about twelve years and a half before: the turf was about half an inch thick; and two inches and a half beneath it was a layer or row of small aggregated lumps of the lime forming, at an equal depth, a well-marked white line. The soil beneath this was of a gravelly nature, and differed very considerably from the mould nearer the surface. About three years since cinders were likewise spread on this field. These are now buried at the depth of one inch, forming a line of black spots parallel to and above the white layer of lime. Some other cinders, which had been scattered in another part of the same field, were either still |575| lying on the surface, or entangled in the roots of the grass. The second field examined was remarkable only from the cinders being now buried in a layer, nearly an inch thick, three inches beneath the surface. This layer was in parts so continuous, that the superficial mould was only attached to the subsoil of red clay by the longer roots of the grass. The history of the third field is more complete. Previously to fifteen years since, it was waste land; but at that time it was drained, harrowed, ploughed, and well covered with burnt marl and cinders. It has not since been disturbed, and now supports a tolerably good pasture. The section here was, turf half an inch, mould two inches and a half, a layer one and a half inch thick, composed of fragments of burnt marl (conspicuous from their bright red colour, and some of considerable size, namely, one inch by half an inch broad, and a quarter thick), of cinders, and a few quartz pebbles mingled with earth; lastly, about four inches and a half beneath the surface was the original, black, peaty soil. Thus beneath a layer (nearly four inches thick) of fine particles of earth, mixed with some vegetable matter, those substances now occurred, which, fifteen years before, had been spread on the surface. Mr. Darwin stated that the appearance in all cases was as if the fragments had, as the farmers believe, worked themselves down. It does not, however, appear at all possible, that either the powdered lime or the fragments of burnt marl and the pebbles could sink through compact earth to some inches beneath the surface, and still remain in a continuous layer. Nor is it probable that the decay of the grass, although adding to the surface some of

1838. On the formation of mould

49

the constituent parts of the mould, should separate, in so short a time, the fine from the coarse earth, and accumulate the former on those objects, which so lately were strewed on the surface. Mr. Darwin also remarked, that near towns, in fields which did not appear to have been ploughed, he had often been surprised by finding pieces of pottery and bones some inches below the turf. On the mountains of Chile he had been perplexed by noticing elevated marine shells, covered by earth, in situations where rain could not have washed it on them. The explanation of these circumstances, which occurred to Mr. Wedgwood, although it may at first appear trivial, the author does not doubt is the correct one, namely, that the whole is due to the digestive process, by which the common earth-worm is supported. On carefully examining between the blades of grass in the fields above described, the author found, that there was scarcely a space of two inches square without a little heap of the cylindrical castings of worms. It is well known that worms swallow earthy matter, and that having separated the serviceable portion, they eject at the mouth of their burrows, the remainder in little intestine-shaped heaps. The worm is unable to swallow coarse particles, and as it would naturally avoid pure lime, the fine earth lying beneath either the cinders and burnt marl, or the powdered lime, would, by a slow process, be removed, and thrown up to the surface. This supposition is not imaginary, for in the field in which cinders had been spread out only half a year before, Mr. Darwin actually saw the castings of the worms heaped on the smaller fragments. Nor is the |576| agency so trivial as it, at first, might be thought; the great number of earth-worms (as every one must be aware, who has ever dug in a grass-field) making up for the insignificant quantity of work which each performs. On the above hypothesis, the great advantage of old pasture land, which farmers are always particularly averse from breaking up, is explained; for the worms must require a considerable length of time to prepare a thick stratum of mould, by thoroughly mingling the original constituent parts of the soil, as well as the manures added by man. In the peaty field, in fifteen years, about three inches and a half had been well digested. It is probable, however, that the process is continued, though at a slow rate, to a much greater depth; for as often as a worm is compelled by dry weather or any other cause to descend deep, it must bring to the surface, when it empties the contents of its body, a few particles of earth. The author observed, that the digestive process of animals is a geological power which acts in another region on a greater scale. In recent coral formations, the quantity of stone converted into the most impalpable mud, by the excavations of boring shells and of nereidous animals,2 is very great. Numerous large fishes (of the genus Sparus) likewise subsist by browsing on the living branches of coral. Mr. Darwin believes, that a large portion of the chalk of Europe was produced from coral, by the digestive action of marine animals, in the same manner as mould has been prepared by the earth-worm on disintegrated rock. The author concluded by remarking, that it is probable that every particle of earth in old pasture land has passed through the intestines of worms, and hence, that in some senses, the term “animal mould” would be more appropriate than “vegetable mould.” The agriculturist in ploughing the ground follows a method strictly natural; and he only imitates in a rude manner, without being able either to bury the pebbles or to sift

50

1839. Observations on the parallel roads of Glen Roy

the fine from the coarse soil, the work which nature is daily performing by the agency of the earth-worm.*

1

2

Josiah Wedgwood II (1769–1843), CD’s father-in-law and maternal uncle. The final paper was published as Darwin 1840, F1655 (p. 124). This topic later culminated in CD’s last book Earthworms (1881). Nereididae are freely crawling polychaete worms.

1839. Observations on the parallel roads of Glen Roy, and of other parts of Lochaber in Scotland, with an attempt to prove that they are of marine origin. By Charles Darwin, Esq., M.A. F.R.S. Sec. G.S. [Read 7 February] Philosophical Transactions of the Royal Society 129: 39–81. F16531 Received January 17th,—Read February 7th, 1839. After the two elaborate memoirs which were read nearly at the same time, before the Edinburgh Royal Society and the Geological Society of London, by Sir Thomas Lauder Dick2 and Dr. Macculloch,3 on the parallel roads of Glen Roy4 and the neighbouring valleys, any detailed account of the physical structure of that remarkable district would be superfluous. But from the excellence of these papers and the high authority of their authors, it is necessary carefully to consider the theories they have advanced,—a necessity I feel the more strongly, from having been convinced during the few first days of my examination of the district, that their conclusions were impregnable. Moreover the results to which I have arrived, if proved, are of so much greater geological importance than the mere explaining the origin of the roads, that I must beg to be permitted to enter into the subject in detail. Section I.—Description of the Shelves The parallel roads, shelves, or lines, as they have been indifferently called, are most plainly developed in Glen Roy. They extend in lines, absolutely horizontal, along the steep grassy sides of the mountains, which are covered with a mantle, unusually thick, of slightly argillaceous alluvium. They consist of narrow terraces, which, however, are never quite flat like artificial ones, but gently slope towards the valley, with an average breadth of about sixty feet. *

Since the paper was read Mr. Darwin has received from Staffordshire the two following statements:—1. In the spring of 1835 a boggy field was so thickly covered with sand that the surface appeared of a red colour; but the sand is now overlaid by three quarters of an inch of soil. 2. About 80 years ago [CD later corrected this estimate to 30 years. See Darwin 1844, F1665 (p. 173)] a field was manured with marl; and it has been since ploughed, but it is not known at what exact period. An imperfect layer of the marl now exists at a depth, very carefully measured from the surface, of 12 inches in some places, and 14 in others, the difference corresponding to the top and hollows of the ridges or butts. It is certain that the marl was buried before the field was ploughed, because the fragments are not scattered through the soil, but constitute a layer, which is horizontal, and therefore not parallel to the undulations of the ploughed surface. No plough, moreover, could reach the marl in its present position, as the furrows in this neighbourhood are never more than eight inches in depth. In the above paper it is shown, that three inches and a half of mould had been accumulated in fifteen years; and in this case, within eighty years (that is, on the supposition, rendered probable from the agricultural state of this part of the country, that the field had never before been marled) the earthworms have covered the marl with a bed of earth averaging thirteen inches in thickness.

1839. Observations on the parallel roads of Glen Roy

51

There are only four shelves which are plainly marked for any considerable length; the lowest one according to Macculloch is 972 feet above the sea; the next above it is 212 feet higher, and the third, eighty-two above the second, or 1266* above the sea; the fourth occurs only in Glen Gluoy; it is twelve feet higher than the third. I shall refer to them either by their absolute altitude, or as being the upper or lower one in the part under description, and not as first, second, or third; for it will be hereafter seen that others occur in every respect similar, only less plainly developed. It is admitted by every one, that no other cause, except water acting for some period on the steep side of the mountains, could have traced these lines over an extensive |40| district. The dark line in the accompanying wood-cut (No. 1.) represents the real profile of a shelf, and is copied from Macculloch. To this I have added two imaginary lines, of which the broken one gives the supposed original form of the underlying rock.

AB supposed original surface of rock; CE line of shelf; CDH line of shelf when expanded into a buttress or terrace.

The formation of the shelf, as may be here seen, is chiefly due to the accumulation of matter in the form of a mound, only very slightly projecting beyond the general slope of the mountain, and partly to the removal or corrosion of the solid rock. The latter effect, although well marked in some particular spots, cannot generally be distinguished, and the shelves no doubt are chiefly due to the accumulation, and not to the removal of matter. In this same diagram (1.) the covering of alluvium is represented as thicker some way below the shelf, than at the same distance above it. I believe this is generally the case, and hence the projection of the shelf is often very obscure; and when two or three occur, one below the other, their outline closely approaches to that represented in wood-cut (2.). Macculloch will scarcely even allow that a shelf in any case forms a projecting mound; but this certainly is incorrect, and is indeed contradicted by his own statements, and by that implied in the comparison of the shelves with the beaches of lakes, which have been suddenly drained. The shelves entirely disappear, where crossing any part of the mountains in which the bare rock

*

Some rude measurements which I made with a mountain barometer lead me to suspect that these altitudes are at least a hundred feet too great. It is not a point of any importance with respect to the theory of the origin of the shelves, but I regret that I did not verify their height with more care.

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1839. Observations on the parallel roads of Glen Roy

is exposed; for loose matter cannot accumulate there, and the rocks themselves from their laminated structure do not readily become worn into any regular form. They likewise disappear where crossing any part which is gently inclined; for their own slope then coincides with that of the alluvial covering, and cannot be distinguished from it. The dotted line in the wood-cut (No. 1.) is supposed to represent the broader terraces, or even plains, of stratified shingle, sand, and mud, with which the shelves often become united. These terraces do not differ from the shelves in any one essential point of structure, but are much broader; and as the matter of which they are composed is in much larger quantity, a rude kind of stratification may be generally observed. They occur only where the bottom of the valley in its gradual ascent rises nearly to the level of a shelf, or at points on the hill-sides, where it is probable that the streamlets formerly brought down much detritus to the ancient beaches. |41| Sir Lauder Dick has observed* that the shelf infallibly intersects the head of such terraces or buttresses: this certainly is the case (as in diagram 1.) with all the smaller ones; and, therefore, we may infer that their formation dates from the period when the shelf was a beach. But at the head of the greater valleys, where the supply of matter must have been more abundant, and where the slope of the land was highly favourable to its accumulation, the line of shelf sweeps across and blends into a plain, which has an uniform slope upwards and downwards above and below that level. Therefore, when the water stood at any one of the shelves, there were many little deltas which did not rise above its level, but some greater ones that were continuous with an upward slope of shingle, filling the bottoms of the main valleys.† The shelves are chiefly composed of the same kind of alluvium with that covering the whole surface of the mountain; and they seem to have been formed, as suggested by Macculloch, by the check given to the downward descent of ordinary detritus, and that transported by torrents, at the level of the ancient waters; I could perceive no difference in the nature of the alluvium above and below the upper shelf, as stated to be the case by Sir Lauder.‡ It contains fewer well-rounded pebbles at the greater heights than would have been expected on any theory of the origin of the shelves; but they are abundant in the lower and broader parts of the valleys. Nevertheless where there is any level spot at the height of the upper shelves, well-rounded pebbles may generally be found, as on the summit of a rounded hill, or a flat little strait separating some hillock from a line of shelf (for instance near Craigdhu, on the summit of Meal Roy, and between Upper and Lower Glen Roy). In these cases the pebbles must have been almost exclusively formed by the action of the currents and waves of the former expanse of water. They are frequently derived from rocks not found in the immediate vicinity: erratic boulders also are scattered over these mountains.

* †

‡

Transactions of the Edinburgh Royal Society, vol. ix. p. 11. These statements are founded on what I saw in Glen Collarig, where the lower shelf (the 972 feet one) blends into a slope, now rendered irregular by the action of the torrents, which rises (at the gap) to a height of more than a hundred feet above the level of the shelf. Again, near the head of Lower Glen Roy, the seam shelf blends into a similar kind of plain, which rises (at the base of a terrace, projecting from the next shelf to it,) ninety feet (barometrically measured) above the level of that shelf to which it may be said to belong. In the east arm of Glen Turet, the upper shelves in a like manner terminate in slopes, which rise above their proper levels. Geological Transactions, vol. iv. (First Series), p. 320–338, and 387.

1839. Observations on the parallel roads of Glen Roy

53

I state these facts distinctly, because Macculloch says* that the composition of the alluvium of the upper shelves is wholly different from that covering the sides of the broad valleys; whereas the difference is only one of degree, for which many causes might be assigned. I have already observed, that the quantity of solid rock worn away on the line of any shelf is not usually great. At the narrow entrance, however, of Loch Treig (of which a drawing is given by Sir Lauder Dick), on the west side, which is very steep, the gneiss is worn into smooth concave hollows, the peculiar curves of which, though |42| they cannot be described, may be readily imagined by calling to mind the form of rocks washed by a water-fall. This was the only one spot where I could observe this appearance in an unequivocal manner; but this one point of rock would to my mind carry demonstration with it, even if there were not innumerable other proofs, that the water had remained at the level of the 972 feet shelf for a very long period.† On the opposite side of the entrance, or gorge, which here slightly bends before entering Loch Treig, the shelf expands into a line of terrace. Standing on the precipitous and waterworn rocks, it required little imagination to go back to former ages, and to behold the water eddying and splashing against the steep rocks on one side of the channel, whilst on the other it was flowing quietly over a shelving spit of sand and gravel. The only other and rather different case of waterworn rock, which I noticed, was at the head of Lower Glen Roy (pointed out by Sir Lauder Dick), where the summits of some irregular hummocks of gneiss on a level with the upper shelf were obliquely truncated by a smooth surface. I have frequently observed a similar structure on the rocky shores of protected harbours. Large fragments of rock are scattered on most of the shelves, of which many are of granite, and have come from a distance, as will presently be described; the greater number, however, have merely rolled down from the heights above. Of the latter, some have fallen recently, whilst others are waterworn, as if they had lain for centuries on a sea coast; and it was in many cases easy to point out, whilst walking along the level shelf, which fragments had been washed by the ancient waves, and which had fallen since. Sir Lauder Dick has observed, and the fact is very important, that the head of Glen Gluoy is separated from the head of a branch of Glen Roy by a flat land-strait, with which the shelf in the former glen is exactly on a level; so that if Glen Gluoy were filled with water to the full level of its shelf, or a few inches above it, besides a great barrier at the lower end, a little mound, perhaps a foot or two in height, would be required to prevent the water flowing into Glen Roy. In the same manner if Glen Roy were closed at its lower end, and if water stood at the level of the upper shelf, it would trickle into the valley of the Spey. The same thing would happen with the lower shelf at the head of the valley of the Spean; and lastly, a short shelf,

* †

Edinburgh Royal Transactions, vol. ix. p. 12. After the elaborate arguments given by Macculloch, to show that no sudden rush of water, or debacle, could have formed the shelves, I should not have offered any remarks on this point, had not so distinguished a person as Sir George Mackenzie (London and Edinburgh Philosophical Magazine, December 1835,) suggested such an hypothesis, without, however, it is fair to add, having visited the district. Each of the ten thousand pebbles, which together form any one buttress or little delta, and which, it is evident, were accumulated by the action of one streamlet, at the spot where it entered the expanse of ancient water,—each of these pebbles required time for its attrition,—each now plainly speaks against such an hypothesis. [George Steuart Mackenzie (1780–1848), mineralogist and phrenologist. Mackenzie 1836.]

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1839. Observations on the parallel roads of Glen Roy

which I discovered in a gully, which enters the Caledonian Canal near Kilfinnin,* between |43| Loch Oich and Loch Lochy, is in a similar manner on a line with a peat moss, forming the watershed between it and another small valley. These four cases are so remarkable, that the coincidence of level must be intimately connected with the origin of the shelves; although such relation is not absolutely necessary, in as much as the middle shelf of Glen Roy is not on a level with any watershed. Sir Lauder endeavours to explain this fact by supposing that when the imaginary barriers of his separate lakes were perfect, the water flowed from that end of the glen, which is now highest, in other words, that the drainage of the supposed lakes was in each case in a reverse direction to that of the streams now occupying their beds. This view implies, moreover, the strange accident, that, during the breaking down of the barriers, the part that was originally lowest always remained standing, whilst a higher part gave way; and thus the removal of the barrier must be supposed to have happened from the effects of some causes no ways analogous to the wearing down of the mouths of lakes as they ordinarily exist. The structure of these land-straits must be now described. This has already been minutely done by Sir Lauder with respect to that one which connects the sources of Glen Gluoy with those of Glen Turet, one of the arms of Glen Roy. The only additional observation which I have to make, is that the strait is broad and very level, and that on one side I noticed a beach, like that on a sea shore, of well-rounded pebbles. The accounts given by Macculloch and Sir Lauder of the division of the waters of Glen Roy and the Spey differ in some essential points. The latter author states that the upper shelf of Glen Roy is on a level (excluding the peat-moss) with the flat where the waters divide. This appears to be accurately the case, as far as the mountain barometer (which stood at the same thousandth of an inch on the two stations) and my eye could be trusted. But on the north side of the watershed there are patches of little terraces about fifteen feet above this level, resembling those which in other parts are connected with shelves, and hence probably having a similar origin with them. On the hill-side higher up, other obscure patches of alluvium occur with somewhat analogous forms. The water of the Spey first flows down a gentle mossy slope eastward, and is then collected in Loch Spey. On the south side of this loch, there is an obscure line of terrace, which appears to be about sixty feet above the loch, and which doubtless led Macculloch to suppose the upper shelf of Glen Roy was that number of feet above the division of water. The terrace above Loch Spey, as far as I could judge by the eye without a levelling instrument, is horizontal, and may perhaps be traced along the south side of the watershed, even a short distance within Upper Glen Roy, where certainly there occurs a mound parallel to and above the upper shelf. I much regret I was unavoidably prevented from examining this locality with all the attention it deserved. But from the structure of the small terraces, it appeared to me certain that water must for a period have occupied a level above that of the highest shelf of *

I was informed, but whether correctly I do not know, that the hamlet (in the middle of which there is a mound with a round tower on it,) on the opposite side of the valley, and a mile or two south of Invergarry, was named Kilfinnin. I therefore shall denominate the small stream which flows towards the Caledonian Canal at that point by this name. In the same manner I shall call the larger stream which debouches by Habercalder, and its valley, by that name, not having been able to learn any more proper one.

1839. Observations on the parallel roads of Glen Roy

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Glen Roy; and likewise that fragments of a shelf, or line of terrace, which as far as the eye could judge was horizontal, extended within |44| the basin of the Spey, and therefore beyond the limits of the supposed lake of Roy. This latter fact is, at least, certain, for I have since learned, through the kindness of Sir David Brewster,5 that he has seen, as will be hereafter mentioned, shelves resembling those of Glen Roy at two points, at a distance of several miles down the valley of the Spey. The watershed at the head of the valley of Kilfinnin, has precisely the same character with the foregoing cases: here also a flat-topped buttress projects on one side above the level of the shelf, and this seems to indicate, as in the former case, the presence of water at a level rather above that of the shelf itself.* The division of the waters between most of the glens and ravines in this district, in situations where no shelves occur, does not take place on a sharp ridge, but on level, and often broad land-straits, similar to those just described. I may instance a long one (at an elevation of between 1400 and 1500 feet above the sea,) separating two branches of the water which flows by Habercalder into the Great Glen, and one branch of the Tarf Water. Again another one nearer Fort Augustus, separating the two lowest and nearest branches of the same two rivers; here also there were obscure buttresses on each side above the level of the watershed. An intelligent shepherd who accompanied me, remarked that this form of the land was common wherever the waters in this mountainous country divided; and I observed several instances of it. Finally, I may remark, without wishing to lay any great stress on the argument, that these land-straits, whether connected with the shelves, or not, are precisely what might be expected from straits, properly so called, between arms of the sea being laid dry. The discovery of any shelf, beyond the limits where they had been hitherto observed, being evidently an important point with regard to the theory of their origin, I shall fully describe the following case. At the head of a small stream which joins the Caledonian Canal, near Kilfinnin, and which is divided from the waters of the Habercalder by a flat mossy watershed already alluded to, some fragments of a shelf occur on the northern side. This shelf resembles in every respect those in Glen Roy; it seemed, as I walked along it, perfectly level, as it likewise did, when I viewed it from either end, and when I crossed the valley. I then took several measurements at the most distant points with the mountain barometer, and the mercury stood within the same hundredth of an inch. On the northern side of the valley, the shelf, which commences on a level with the mossy plain dividing the waters, extends for about a quarter of a mile almost continuously; it is then lost from the number of fragments of rock which have fallen down the hill, but reappears at the distance of more than half a mile from its commencement under the form of two or three little buttresses. These I ascertained by the barometer to be on a perfect level with the commencement of the shelf, or the watershed, a circumstance which was also apparent by the eye alone. The line further on disappears from the rockiness of the sides of the valley. |45| On the south and opposite side of the valley, a broad sloping terrace extends at a corresponding level for about three quarters of a mile, but is indistinct owing to the gentle slope of the mountain. Further on it seems modelled into more than one terrace: and these, *

The pass of Muckul, described by Sir Lauder, which separates the waters of the Spean from a branch of the Spey, I did not visit.

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1839. Observations on the parallel roads of Glen Roy

though obscure, appear to a person standing on them perfectly horizontal. Although the terraces are not plainly developed on this side, yet it is certain, that horizontal mounds, at nearly the level of the watershed, extend about two miles on the face of the mountain. With respect to the absolute elevation of this shelf, I made it about forty feet above the upper one of Glen Roy, and 1120 above Loch Lochy, or 1202 above the sea: but my barometrical observations have no pretensions to accuracy. After having observed this shelf from so many points of view, I am prepared positively to assert that it is in every respect as characteristic a shelf as any in Glen Roy; and although the fragments of it do not extend over more than, perhaps, half a mile in length, its origin must be as carefully attended to in any general theory of the formation of the shelves, as if its length had been twenty times as great. Its want of continuity and shortness possess, indeed, in themselves much interest, because we thus know that those causes which have marked with horizontal lines the sides of the mountains of Glen Roy in so wonderful a manner, have been in action here, though they have produced but little effect. Moreover, we see that if the surface had been originally rather more rocky, or had been less steeply inclined than at present, or had been subjected to a very little more alluvial action, all evidence would have been obliterated of the extension thus far of the action of these causes. I have already alluded to the important fact communicated to me by Sir David Brewster, namely, that he has seen shelves in the valley of the Spey. At Phones, which is situated about a mile from the Truim, and about five above its confluence with the Spey, one broad and well-marked shelf occurs, along which a carriage can be driven. On the banks of the Spey, about twenty-five miles below its source, two shelves occur in an elevated angle between the Burns of Belleville and the river. They are small; the upper one, however, is very broad; and their elevation is about 800 feet above the sea. Sir David Brewster says, that the shelves in both places appear horizontal, and that they resemble those of Glen Roy, though possessing far less grandeur and symmetry. The fact of their occurrence at these distant points is, as we shall hereafter see, highly important. Section II.—The Theories of Sir Lauder Dick and Dr. Macculloch considered Sir Lauder believes that a separate lake existed in each valley, where we now see a shelf, and was separately drained. In Glen Roy, where three shelves occur, all plainly developed, (with the exception of Belleville, this is the only place where more than one has been observed,) the arguments in favour of a separate lake possess the greatest force. Without entering into any description of the physical features of Glen Roy, inspection of the accompanying map, taken with some few alterations |46| from that of Sir Lauder Dick, will show the course of the shelves; although they cannot of course be followed nearly so continuously in nature as here represented. The lower one (972 feet above the sea) is common to nearly the whole line of the Spean and Glen Roy. The two upper shelves are confined to Glen Roy, with the exception of those short portions extending into Glen Collarig. It will be seen that both these lines, if continued round the hill of Bohuntine (at the eastern entrance of Glen Roy), would insulate it, whilst the lower shelf only forms it into a peninsula. From this structure it will be evident, that in order to form Glen Roy into a lake at either of the two upper levels, it

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would be necessary to erect two barriers, one across Glen Collarig, and the other principal one across the mouth of the Roy. The lines are here represented as if abruptly cut off, but this is not so; and the following remark holds good in other cases, namely, that where a shelf terminates without any visible change in the nature of the slope, such as being rocky, &c., its disappearance is so extremely gradual, that it can be traced, sometimes to a further and sometimes to a lesser distance, according to the point from which it is viewed. Of this fact the shelves on the south-east side of Glen Collarig offer an excellent example. In the map, the extremities of the lower of the two upper shelves are represented at the four places where they terminate, as extending beyond those of the upper one. I state this on the authority of Sir Lauder Dick with respect to those in Glen Roy, and it is conspicuously the case with that pair in Glen Collarig which I have described as disappearing in so insensible a manner. The lower line can there be traced, though faintly, to a point below the houses of the glen opposite a small tributary torrent, and therefore considerably beyond (or nearer the mouth) than the point where the 972 feet shelf crosses the bottom of the valley. Observing in Glen Collarig the gradual disappearance of either set of lines, and that there is not the smallest apparent cause for it in the nature of the ground, the first and obvious supposition is that a sheet of water extended from the Spean into Glen Roy and Collarig, and that the mere widening of the mouths of the latter, as they approached the less protected expanse of the Spean, gradually became unfavourable to the accumulation of detritus, and therefore to the formation of the shelves. This view is greatly strengthened by the extension of the lower line in each case beyond the upper; for of course the supposed unfavourable condition for their formation, that is, the too great breadth and exposure of the sheet of water of which they formed the beach, would affect the line when the water stood at the higher level to a greater distance from the main expanse, or further up the valley, than when it occupied a lower level. It may, however, be argued (and on the hypothesis of Glen Roy having existed as a lake it must be so argued), that as the higher line is the oldest, so its terminal portion may soonest have yielded to those causes which modify the surface of the land. This view, however, receives little support from an examination of the rest of the glen, inasmuch as the two shelves through its whole course are in a state of equal preservation. We must therefore conclude, either that we now behold the shelves |47| precisely as they were left by the sheet of water, or that if the two upper shelves did originally extend for an equal length on each side of the two glens, that the causes which tend in a small degree (for the existence of the shelves proves that no great changes have taken place) to smooth the surface, have acted over this district with the most perfect uniformity. Moreover, it may be remarked, that wherever a streamlet crosses a shelf, and it is probable from its size that it formerly delivered detritus to the ancient expanse of water, either a greater breadth of shelf or a small buttress there, attests that it was so; and in doing this, likewise attests how perfectly the surface of the land has been preserved. Now I paid particular attention to the following observation, namely, that on both sides of the hill of Bohuntine, and on the opposed mountains, where the shelves terminate, there was not the smallest change in the composition or in the outline of the smooth rounded surfaces. Yet it is in this very spot, where the lines insensibly disappear,—on these very hills, where the little

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deltas of the ancient streamlets are still preserved,—within this very district, where in the extension of the lower shelf beyond the upper one in the four cases, we have the most satisfactory proof of the action of absolutely uniform causes, either in their formation or in their obliteration; it is here, where the slope of the turf-covered hills is unbroken, where there is not a remnant of any projecting mass, that we are compelled by the theory to believe that the two enormous barriers stood, which formed Glen Roy into the imaginary Loch Roy. But as it is highly important to show that such a Loch could not have existed, we must for a time, in the face of these great difficulties, suppose the two barriers to have been erected. It may be first remarked, that from the extension of the middle shelf, the barrier in Glen Collarig could not have occupied the only one place, which the structure of the ground indicates, even in the smallest degree, as probable, namely, at the Gap, where the waters divide; but it is necessary to suppose that it crossed the glen at a point some way distant from the Gap, and where the valley has a depth, below the upper shelf, of more than 300 feet. Glen Roy being now converted into a lake, with its drainage reversed, that is, with the water flowing from it by the Spey to the east coast of Scotland, let one of the two barriers, we will say the smaller one in Glen Collarig, give way from the effects of an earthquake or other cause. The lake will now stand at the level of the middle shelf, the barrier having given way eighty-two feet vertically. Again let it burst, and this time rather more than 212 feet vertical must be swept away, so that the larger lake, supposed by Sir Lauder’s hypothesis to occupy the valley of the Spean at the level of the 972 feet shelf, might send an arm a little way up the glen (as shown by the shelf now existing there) above the point where the barrier stood. Let all this have taken place, but still a barrier nearly a mile long, and 800 feet in height, is left standing across the mouth of the Roy. Must we suppose that each time the barrier in Glen Collarig failed, the one in Glen Roy gave way the same number of feet through some strange coincidence? or are we to conclude that some awful catastrophe at subsequent |48| times, unconnected with the drainage of the lake, which must have passed through the breach already opened, removed the second barrier (either part or all of it) when above water, without having left the smallest remnant of it, or having disturbed the smooth alluvial covering of the steep slopes? The 972-feet shelf is common to the valley of the Spean and Glen Roy, and is supposed to have been formed by a lake, the barrier of which, some miles in length, extended near Highbridge across the mouth of the Spean. This shelf passes uninterruptedly, and with its usual breadth, on both sides of Glen Roy and of Glen Collarig, in the very part where the barriers of Loch Roy, if they existed, must have crossed the valley; therefore the whole, or part of the great base of those enormous barriers, must have been swept away when submerged within the bosom of the imaginary Loch Spean; and this must have been so perfectly effected, that no trace of them is left on the smooth slope of the hill, not even by a greater breadth of the shelf, any more than in the part of the second barrier, which must have been removed when above water.* And all this *

I have not thought it worth while to enter into all the possible cases of this hypothesis, but have merely taken the most obvious one, which was assumed by Sir Lauder. If any one has the boldness to come forward from the obscurity of past times, and state his belief that the broad barrier of the Spean was erected as well as removed altogether subsequently to the removal of the two barriers of Glen Roy, then the objection from the uniform breadth of the 972-feet shelf, where crossing the spot which must have been occupied by the barrier of Loch Roy, has less weight, but the other part of the argument remains valid. Again, on the hypothesis in

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is supposed to have taken place on the hills, where I have shown how wonderfully the features of the land have been preserved, and where the boulders which were washed by the waves of the ancient water can be distinguished from those which have fallen since. In conclusion, therefore, I do not hesitate to affirm, that more convincing proofs of the non-existence of the imaginary Loch Roy could scarcely have been invented, with full play given to the imagination, than those which are marked in legible characters on the face of these hills.† The same reasons which render the existence of a separate lake in Glen Roy so excessively improbable, apply with only little less force to each of the imaginary lakes in the other glens. We are, therefore, in giving up Loch Roy, involuntarily driven to the theory advanced by Macculloch, namely, that all the valleys in which shelves occur were included in one large lake; but we shall thus run headlong even into greater difficulties. First, from the structure of the mountains, four immense barriers are required to form the lake,‡ namely, one low down across the valley of the |49| Spey, two at distant points across the Great Glen of Scotland, and a fourth across the mouth of Loch Eil, the last being necessary, as Macculloch shows,§ from the structure of the Great Glen in that part. It may be safely asserted that more improbable situations could hardly be imagined in the whole of Scotland. It is perhaps useless to ask, were the barriers composed of rock or alluvium? if of the former, they were transverse to every line of hill in this part of the country; if of alluvium, we must assume an unexampled case; for where in the whole world shall we find even one barrier a mile and upward in length, and 1200 feet high, composed of loose waterworn materials? Secondly, the theory of one large lake does not explain in a satisfactory manner the remarkable coincidence between the shelves and the watersheds. Thirdly, when by the bursting of any one of the barriers, the level of the lake had fallen from one shelf to another, the hypothesis requires (as with Loch Roy) that the three other barriers, now high and dry, and distant many leagues from each other, should have been swept away by some unknown power, acting by some unknown and scarcely conceivable means, from the smooth sides of the mountains, without a remnant of them having been left; so that Macculloch even frankly confesses one part is almost as probable (I would say improbable) as another for the position of the barriers. And it should be borne in mind, that these extraordinary forces are supposed to have acted on the outskirts of that large area, throughout which we have proofs, most wonderful and unequivocal, of the entire preservation of the surface of the land, as it was left at a period long anterior to the removal (if such removal ever did take place) of the barriers of the lower lakes. I do not hesitate to assert that this one difficulty, even by itself, would be sufficient to refute the theory of one great lake: Sir Lauder’s theory has been shown to be equally

†

‡

§

the text, I have not entered into all the possible alternatives of the manner in which the bases of the Loch Roy barriers might have been removed, either when Loch Roy itself, or when Loch Spean was drained, or at some subsequent period by unknown causes connected with the drainage of the imaginary lakes. It should be remembered that it is far easier to assert than to disprove. If to explain some phenomenon it was stated that the Thames near London was formerly crossed by a barrier some hundred feet in height, of which it was not pretended a vestige now remained, it is difficult to imagine what kind of evidence would be sufficient to prove the hypothesis false, as long as any one was found willing to admit such an assumption. I may add, the same number of barriers are requisite, whether we suppose the existence of one, two, three, |49| or as many lakes as glens; and the argument against Macculloch’s hypothesis of one lake, and against that of the separate lakes by Sir Lauder, are applicable to any hypothesis requiring an intermediate number. Geological Transactions, vol. iv. p. 378.

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untenable. It is perhaps here almost superfluous to add, that the discovery of the shelf at Kilfinnin (and probably likewise of those in the valley of the Spey) increases every difficulty manifold; for the valley of Kilfinnin is almost as wide as it is long, which affects one theory, as the lowness of the opposite side of the Great Glen does equally the other. Finally, then, in giving up both, the conclusion is inevitable, that no hypothesis founded on the supposed existence of a sheet of water confined by barriers, that is, a lake, can be admitted as solving the problematical origin of the “parallel roads of Lochaber.” Section III.—Proofs of the retreat of a body of water from the central parts of Scotland, and that this water was that of the sea Having now discussed these views which cannot be admitted,—a method of reasoning always most unsatisfactory, but necessary in this instance from the high authority of those who have advanced them,—I will consider some other appearances, |50| which will perhaps throw light on the origin of the shelves. The valley of the Spean, from the point where it joins the Great Glen of Scotland to where it receives the Roy, is broad, and its bottom moderately level. The solid rock is concealed in almost every part, excepting where the river has cut itself a gorge, by irregularly horizontal strata of gravel, sand, and mud. Large portions of these beds have been removed along the centre of the valley, yet it is quite evident from the fringe or line of terraces which skirt each side, that the bottom must originally have formed a smooth concave surface inclined towards the mouth of the valley. Portions more or less perfect of this same deposit can be followed up the course of the Roy, and up the higher parts of the Spean, where the valley is not too rocky or narrow, to near Loch Laggan. This loch is but little below the 972-feet shelf; and at present I wish, for the sake of the independence of the argument derived from the facts to be stated, to consider only that part of the country which is below the level of that shelf. These irregularly stratified beds, near the mouth of the Spean, attain a thickness of several hundred feet, and they consist of sand and pebbles, many of the latter being perfectly waterworn. Higher up the valley, near the bridge of Roy, the thickness before the central portions were removed appears to have been about sixty feet, but of course the thickness varies according to the original irregularities of the rocky bottom of the valley. Now it may be asked by what agency has this sloping sheet of waterworn materials been deposited along the course of the valley? From the presence of the horizontal shelves we know that there has been no change in the relative level or inclination of the country since this district was last covered with water, and therefore we may argue with safety, that the action of the rivers, as far as it is determined by their inclination, must have been the same since that period as it now is, with the exception of that amount of change which they may have effected in their own beds. Our knowledge that there has been here no axis of elevation, with one part always rising a foot, and another a few inches less; but that the entire system of drainage has remained undisturbed and subject only to its own laws of change, is a circumstance which gives a singular degree of interest to the examination of this district. Now if we look at any portion of these rivers, for instance the Roy above its junction with the Spean, we find it has cut a narrow steep-sided gorge through the solid rock, which is in many parts between twenty and thirty feet deep, whilst on each side there are remnants,

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as above stated, of a continuous bed of gravel, at least sixty feet in thickness. These beds have certainly been deposited by rapid currents of water, but not by any overwhelming debacle, as may be inferred from the presence of cross layers, and the alternate ones of fine and coarse matter. Seeing also the evident relation of dimension and materials which exists between these deposits and the valleys in which they occur, it can scarcely be doubted that the detritus of which they are composed was transported by the existing rivers. But are we to suppose that the river, as in the case of the Roy, first deposited along its whole course these layers one over another, thus raising its bed sixty feet above the solid rock, and then |51| suddenly commenced, without the smallest change in the inclination of the country, not only to remove the matter before deposited, but when having gained its former level, to act in a directly opposite manner, and to cut a deep channel in the living rock? Assuredly such a supposition will not be received; and whatever part the river had in the accumulation of these waterworn materials, from the very moment (neglecting the annual oscillations of action from the changing seasons) it ceased to add and began to remove, its power must have undergone some most important modification. It will perhaps be thought that the mere deepening of the bed of the stream, near the mouth of the valley (the effect being slowly propagated upwards), could have caused the difference between the present and the former action of the river. But it is not difficult to replace in imagination the solid rock in the course of the Spean; and although a few small lakes will be thus formed, the average slope will not differ greatly from the present inclination, and this inclination we see is sufficient to cause the river to wear a deep gorge in the solid rock, and therefore it is evident (although I am aware that without actual measurement of the inclination this argument must rest upon eyesight, which cannot generally be trusted) that a change of this nature would be wholly insufficient to reverse the action of the river, as has here been the case. We must not, of course, at the same time replace in imagination those unconsolidated deposits, the origin of which we are considering; otherwise no doubt the inclination of the bed of the river would be greatly altered; although even in that case I by no means believe that the river would be so much retarded as to deposit matter at the heights where it is now left. Some check, therefore, to the transporting power of the stream seems to have acted at many, or at every successive level. If we reflect on what would result, as an hypothesis, from a river delivering during a long period detritus into a lake, the level of which was gradually sinking from the wearing down of its mouth, a gently sloping surface would be formed at its head. But as the barrier was cut deeper and deeper, and the lake sank, the stream in the part where it was once checked by meeting with the still water would gain velocity, and hence would cut through the beds which it had originally deposited. The fringe, of rudely stratified alluvium, the origin of which we are considering, resembles both in structure and composition such beds of detritus as would have accumulated on the shores of a lake, had one existed in these valleys. If, then, we suppose that a subsiding sheet of water did actually fill this valley, either of one or more lakes, with their barrier gradually wearing down, or of an arm of the sea, the general level of the ocean being stationary during a slow elevation of the land (as now is the case with the fiords of Scandinavia), every appearance on the sides of the valley of the Spean and Roy will be explained; and as there

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is no other way, that I can see, of accounting for them, the hypothesis is so far worthy of admission. I ought, perhaps, to have previously observed, that these deposits could not have been formed when the valley was filled with water to the level of the shelves, for the |52| detritus has the character of matter accumulated in shoal water, and the beds abut abruptly against the bases of the mountains, instead of blending with the alluvium on their surface, as would necessarily have happened had the whole been deposited at the same time at the bottom of one basin. The conclusion, that these valleys have been occupied by a sheet of subsiding water, follows more plainly from a somewhat different class of facts. I have before remarked, that where a streamlet crosses a shelf, especially if it be the lower one, an obliquely truncated buttress, the form of which was represented by dotted lines in the wood-cut No. 1, projects from the side of the hill. It is quite evident that these were accumulated when the shelf existed as a beach, and the streamlet at present only acts in removing those portions with which it comes in contact. Now in some points where the buttresses have been somewhat largely developed, smaller ones at a lower level, composed of the same irregularly stratified waterworn materials, having nearly the same outline, although unconnected with any shelf, may be observed adhering to the slope of the hill. Instances of this structure occur on the east side of Glen Roy; on the south side of the Spean, and between Loch Treig and the bridge of Roy, the accumulation of perfectly rounded shingle, like that on a sea-beach, was enormous.

The internal structure in this instance corresponded to the external form, as is shown in the accompanying diagram, where highly inclined beds of sand and coarse gravel are capped by other irregular ones of the same composition, only slightly inclined. In all these cases, where the flat-topped buttresses occur on steep slopes, it is certain (as might have been expected) that the streamlet is steadily at work in removing matter, and does not add one pebble to the mound. No one will dispute, that those buttresses, which are mere extensions of a line of shelf, were formed at the edge of an expanse of water (of which the shelf was the beach), and it is therefore by itself probable that the other buttresses, of similar external form and composition, though occurring at a different level, had a similar origin. But the argument may be put in a stronger point of view: taking the course of one of these streamlets, and

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observing the size and position relative to it of the buttresses one above the other, it becomes evident that the materials of which they are formed were accumulated through the agency of this stream, although it is at the same time inconceivable that they were left (especially in such a case as that represented in diagram 3.) on the steep slope by a power which, as it now acts, is steadily at work, tearing away matter in its whole downward course. Therefore, it is absolutely necessary to bring into play some intervening or modifying cause in the action of the streamlet; in the case of the buttresses which are connected with the shelves, no one can doubt what this intervening cause has been; shall we, then, rejecting a vera causa, seek some other one, if indeed such other can be found? Certainly |53| not; and the conclusion is inevitable, namely, that a sheet of water must have stood at as many levels as there are buttresses, and this will include by short steps the whole space between the bottom of the valley and the lower shelf. Judging also from the amount of matter accumulated, we must infer that the water remained at these levels for no inconsiderable periods, although for a lesser time at each than at the level of the 972-feet shelf. I would even further add, that in any valley (the relative level of the country, one part with another, having remained constant) a single buttress, if composed of such materials as could not have slided down the face of the hill in mass, or could not, judging by the presence of cross layers and alternations of fine and coarse beds, have been deposited by a debacle, indicates that the valley was once partly or entirely filled up to that height by such matter; and if the mass be too thick, or at too great an elevation on the sides of the valley, to allow of the supposition that it was deposited by the streams now flowing in the valley, subject to such changes in its velocity as by the corrosion of its own bed it could effect, then the formation of such buttresses can be accounted for only by the supposed permanence of a sheet of water, whether of a temporary lake or of the arm of the sea, at their levels. Now such projecting masses are extremely common in the sides of most of the tributary streams of the valleys. I conclude, therefore, from the consideration both of the beds of stratified alluvium at the bottom of the main valleys, which there is the greatest difficulty in believing could have been deposited by the rivers under the existing conditions; and of the buttresses on the sides of the hills, which similarly could not have been formed by the present streamlets, that it is satisfactorily proved that the valleys of the Spean and Roy have been occupied by a sheet of water which has slowly and very gradually retired, leaving in almost every part unequivocal evidence of the check which matter drifted by a current meets with, when it arrives at or near to the surface of still water. I have as yet confined my argument to the valley of the Spean and its tributaries, and to that portion of it which is below the lower shelf; but I may here add, that it may be inferred from the same kind of evidence already used, (I allude more particularly to some buttresses above the 972-feet shelf to the north-east of the houses of Glen Turet, and to a shelf intermediate between the two upper ones, Tombhran,) that water long remained in Glen Roy at an altitude above that which we have as yet been considering, and at other levels besides those indicated by the three shelves themselves. If, also, we look to other valleys in this part of the country, we find similar appearances. For instance, on the flanks of the valley of the Tarf Water, which flows into Loch Ness (at the elevation of about 1000 feet, near the

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bridge, where the road to Garviemore crosses the river), there are large conical piles, with their summits truncated by a rude terrace, composed of well-rounded pebbles, sand, and an argillaceous earth in irregular beds. Some of the layers of sand and fine gravel were in curves, but slightly inclined; and this structure, together with their |54| composition, made it at once evident that they must have been drifted into their present position by currents of water. Again, near Fort Augustus, the Great Glen, with the exception of the central part, where the river has worn for itself a broad course, is filled with irregular strata about thirty feet in thickness of sand, gravel, and coarse shingle. In the sand some of the layers are most regularly waved, as if by a tide ripple. These beds are about seventy feet above the sea; fringes of similar deposits skirt at intervals both sides of the Great Glen, but where they are present they do not occur, as far as I was enabled to observe, at a greater height than about 100 feet, that is, than the water-shed of this great valley,—a fact somewhat analogous to the coincidence in level between the true shelves or roads and the heads of the valleys in which they occur. At the south-west end of the Great Glen, nearly opposite to Loch Leven, there are some extensive flats, which from a distance appear to be similarly composed, and which in one part have been modeled into two nearly regular terraces, one rising above the other. A somewhat similar structure may be observed in a part between Loch Eil and Loch Lochy; and this structure can only be explained by water having successively occupied for long periods different levels. Referring now to more distant points, we find in the broad valley below Loch Tulla (a tributary of Loch Awe, and the stream flowing thence enters Loch Etive,) there are some appearances, although obscure, of the bottom of the valley having been once filled up with stratified alluvium. On the river Tay, however, near Loch Dochart, the phenomenon is clearly developed. On the south side there is a long mound or terrace, about 150 feet high, entirely composed of well-rounded pebbles mingled in layers with a yellow sandy clay. From this point to Tyndrum (at an elevation of between 400 and 500 feet above the sea) there are similar banks of waterworn materials, and in more than one part I observed a fine white sand, like that on the seashore. On each side of the valley where it divides, near Tyndrum, a broad expanse is scattered over with low ridges and flat-topped hills of equal height, from which it would appear that the whole space had once been covered up with these deposits. Towards the mouth of the Tay the terraces and platforms of Strathmore have been remarked by many observers, on the sides of the small neighbouring valley of the Dighty. Mr. Blackadder,6 in a letter to Mr. Lyell, says, “A narrow track of gravel, sometimes in the shape of platforms, at others in small hillocks, very similar in appearance to those of Strathmore, extends to the height of about 600 feet; and some isolated patches on the southern face of the Sidlaw Hills occur at a greater elevation.” From expressions used by Macculloch and other writers, I am led to believe that beds of similar matter irregularly superimposed over each other, occur on the sides of almost all the valleys of Scotland. In such cases as in that of Loch Dochart, we have no proofs, as horizontal shelves or ancient beaches have not been preserved, that the relative level of the country has remained the same, since the period when it was first traversed by running streams; and therefore it is not absolutely certain that the present rivers, with a very different inclination, might not have

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deposited the |55| rudely stratified beds in the lower part of their courses, and afterwards with an altered velocity have cut through them. But as we do know that no such change has affected a large neighbouring region, and as such movements could hardly thus have influenced the drainage of valleys directed towards different quarters, such doubts may be overruled. This being the case, the same argument as before used may be repeated, namely, that the waterworn materials appear to have been transported by the present rivers, and yet that they are so deposited as could not have happened without some intervening cause. The phenomenon demands an explanation; and the only obvious solution is that which from several and nearly independent considerations was proved to have been the case with the Spean, namely, that it had been occupied by an expanse of gradually subsiding water, either of a lake or of an arm of the sea. This conclusion, therefore, may be urged with only little less force regarding many, if not all, of the valleys in this part of Scotland. It may be asked, of what nature was this sheet of water? If we suppose a barrier erected across the mouth of each valley, and a lake to be thus formed, which sunk from the gradual deepening of its mouth, all the appearances above described would be explained. It is a startling assumption to close up the mouth of even one valley by an enormous imaginary barrier; to do this with all would be monstrous. Of such barriers in the district we are considering I need not say there does not exist any trace, nor need I repeat what I have already said against so vain a supposition as that they could have been swept away by any great debacle from the sides of those hills, of which the whole alluvial covering has been preserved since the period when the upper shelves formed beaches, without even a remnant of them being left; and I may add, that it will hereafter be shown by the clearest proofs, that the ordinary alluvial action, and likewise that of running water, even under the most favourable circumstances of a waterfall, has been far less efficient than could have been anticipated. But it may be asked, would not the hypothesis of a succession of lakes explain the appearance, the matter accumulated above each delta sloping upwards from one level to another. I can only answer this with respect to those valleys which I have myself seen: in the Spean, Roy, Tarf Water, and some others, it is easy, as before stated, to replace in imagination the solid rock; and although some small lakes* would be |56| thus formed by the replaced barriers (as probably would be the case in every valley), the fringe of stratified alluvium we are now speaking of skirts the valley at an elevation above them. To assume that these rocky barriers were formerly much higher, and were demolished by some means independent of the action of the river (for this action tends only to form a narrow wall-sided gorge, as may be seen in those barriers which certainly did exist), would be as gratuitous as *

Sir Lauder has represented three in his map (Edinburgh Royal Transactions) by the figures 5, 6, and 7. I cannot, however, by any means agree with him in the limits thus assigned to them. Is it meant to be asserted, that there is any barrier perfect, with the exception of such a gorge as the river is now cutting, at the lower end of number (7), on a level with the line at its upper extremity; or so nearly so as to allow of the upper part being considered as a supralittoral delta? Such did not by any means appear to me to be the case. Was not the barrier only supposed to have existed, as in the theory of the shelves? I must also observe that the fringe or deposit does not terminate a little way within the mouth of the Roy, as represented by the line marked (7). It appears to me unfortunate that Sir Lauder marked the limits of these deposits, which are accumulated in a gentle slope, in a similar manner as he has done the shelves, which are horizontal. Any one would suppose the lines 5, 6, and 7 were horizontal, like those marked 1, 2, 3, and 4, This difference alone indicates a corresponding one in their origin, as will hereafter be attempted to be shown.

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the imaginary erection of one great barrier across the mouth of the valley, and would explain, from the continuity of the slope, the appearances far less perfectly. Moreover, if the origin of the sloping fringes could be explained by the assumed former existence of a chain of lakes, the buttresses high up on the sides of the valleys clearly could not be so. Nor will any one pretend that any lake-theory can be applicable to the deposits on the sides of the great valleys, such as Strathmore, and the Great Glen of Scotland, which terminate in deep and open friths. Therefore it has not been the water of several lakes any more than of one lake, which slowly retiring from these valleys, determined the accumulation of the beds, where we now see them. There is, then, as we have conclusive evidence that an expanse of slowly subsiding water did occupy these spaces, but one alternative, which we are compelled to admit, and this without any consideration of the shelves themselves, excepting so far as they serve as artificial levels to show that the country has not been unequally elevated, namely, that the waters of the sea, in the form of narrow arms or lochs, such as those now deeply penetrating the western coast, once entered and gradually retired from these several valleys. Section IV.—Proofs from organic remains of a change of level between the land and the sea in Scotland. The effects of elevation traced in hypothesis Another question immediately arises; did the waters of the sea slowly subside, or the land slowly rise, the effect in each case being similar? But first it will be proper to show, from the more ordinary kind of evidence, that there has been some change of level between land and water affecting Scotland within recent times, although not to the amount inferred from the arguments above advanced. Mr. Smith7 of Jordanhill, in an excellent paper,* has lately shown from the presence of elevated organic remains, that within a period geologically extremely recent, both the east and west coast of Scotland has been raised some hundred feet; namely, at Banff and near Glasgow† about 350 feet. Considering the facts given in this paper, it can scarcely be doubted, without making the most improbable assumptions, that the Great Glen of Scotland, of which the highest point is only ninety-three feet above the sea, was within this recent period an open strait; and, I may add, it must then have strikingly resembled the Beagle Channel in Tierra del Fuego, an arm of the sea narrower, longer, and straighter, which intersects the extreme southern part of South America. In accordance |57| with this fact, I was informed by the person who now has the charge of the locks on the canal, that when they were cutting through the gravel at the head of Loch Ness many broken sea shells were found in the lower part, which appeared to him like those on the sea-coast. When exposed to the atmosphere they soon decayed. This point must be between forty and fifty feet above the level of the sea. There are remnants, as before stated, in this part of the Great Glen, as well as at the south-west extremity, of coarse sublittoral formations, which, I suppose scarcely any one would dispute, were accumulated before that small change of level took place, which is indicated by the elevated marine remains. That the movement

* †

Edinburgh New Philosophical Journal, vol. xxv, p. 376. [Smith 1838.] Edinburgh New Philosophical Journal, vol. xxv. p. 386 and 387. The elevated shells at Banff were observed by Mr. Prestwich, Proceedings of Geological Society, May, 1837. [Joseph Prestwich (1812–96), geologist and businessman. Prestwich 1837.]

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must have been exceedingly slow, may be inferred from the existence of so many beaches, each requiring time for its formation, which rise one above another on both coasts of Scotland. Mr. Malcolmson* mentions no less than eleven in Elgin, from the lower one of which he procured twelve species of existing marine Testacea. On the opposite coast also, Mr. Smith has described† several ancient beaches between the present one, and the great terrace, between thirty and forty feet high, which “forms a marked feature in the scenery of the west of Scotland.” It is also important to observe here, that the supposed greater movement deduced from the nature of the superficial deposits, is of precisely the same slow kind, and interrupted (as will presently be shown) by periods of rest, as this lesser movement, attested by the presence of sea shells and step-formed beaches. If, then, the Great Glen was for a long period occupied by an arm of the sea, which very slowly retired from it, deposits must have accumulated on its shores, and likewise for some little distance within the mouths of the valleys which entered it. If we suppose that the sea stood at the same level in the Great Glen as it lately did both on the east and west coast, then the salt water would have almost entered Glen Roy, and would have wholly covered that sloping fringe of gravel, which has been so often mentioned as skirting the course of the Spean. Whether this be granted or not, after what has been stated it can hardly be disputed, that within recent geological periods an arm of the sea entered at least the mouth of the Spean, and very slowly retreated from it. Remembering that the conclusion was forced on us by distinct lines of arguments, that a body of water must have slowly retired from these valleys, and that lakes sufficiently large to have produced the observed effects could not have existed in them, may we not, with the additional consideration that some parts of the deposits here must be of marine origin, deliberately affirm it proved, that it was the waters of the sea that, even at great heights, checked and banked up at successive levels, the detritus brought down by the ancient rivers and streamlets? I am aware that the argument would have had a greater appearance of strength had I commenced with the inference deduced from the presence of recent shells at considerable |58| elevations on both coasts of this kingdom, but I preferred the method I have followed, because I believe it is equally legitimate, and of more general application, although at first not so obvious. From these facts it is certain that there has been a change of level affecting within recent times the whole central part of Scotland, and of a kind very similar to that which has been the subject of so much attention in Sweden, where, according to Mr. Lyell, remains of existing marine animals have been raised to the height of between 500 and 600 feet above the sea. The change of level in the case of Sweden is as certainly known to be due to a slow movement of the land, and not of the water, as it is on the coast of Chile, where a small tract is violently upraised during an earthquake, the distant parts of the same coast being unmoved. It would, however, be quite superfluous here to enter into this question at length,

*

†

Proceedings of the Geological Society, 1838, p. 669. [John Grant Malcolmson (1803–44), surgeon and geologist. Malcolmson 1838.] I was informed by an intelligent quarryman that he had observed many broken sea shells in a gravel-pit, about two miles north of Grant Town, on the roadside to Forres, and therefore eighteen miles from the nearest sea-coast. Edinburgh Philosophical Journal, p. 388.

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as it has almost ceased to be debateable ground.* It may then be concluded that the supposed great change of level in Scotland, deduced from the foregoing arguments, as well as that smaller fraction of it attested by marine remains and ancient sea-beaches, is due to the rising of the land, and not to the sinking of the waters. We will now endeavour to trace in hypothesis the effects which would be produced by an arm of the sea slowly retiring from inlets during an equably progressive elevation of the land. In a deserted sound or flat-bottomed valley, surrounded by mountains, curved lines crossing the river would mark the ancient beaches. Each of these lines would be higher than its neighbour on the sea-side, owing to the rising of the land in the interval of their formation, and would be more distant from the head of the valley, chiefly on account of the matter brought down by the river, and in some parts from the natural slope of the fundamental rock. When the upper line formed a beach, it is evident that the whole of the lower part of the valley must have been under water, and that the prolongation of the beach would stretch along the flanks of the adjoining mountains some way inland from the present shore. In like manner each successive and lower beach-line would wind along the steep sides of the hills, and cross the valley further and further from its head. It should be observed, that although I have spoken of successive beach-lines, yet as the land is supposed by the hypothesis to rise at a perfectly equal rate, every part of the valley will have successively formed, during an equal period, a beach; so that each part having been similarly exposed, the slope will be uniform; nor will it be possible to distinguish any one line of beach. Again, if we suppose matter to be removed from the valley by the action of the tides, instead of being added to it by the river, yet as an equal quantity (or a quantity insensibly varying from the varying degree of exposure, as the form of the land slowly changes during its rise) would be removed at each level, the slope in this case also would be uniform. In that part of each successive beach, which winds along the steep flanks of the mountains, it is not probable that much matter would be added, but the downward descent of some portion of the detritus, which is |59| formed on all land by meteoric agency, would be checked; but as it would be equally checked at each successive level, the outline of the mountain would remain unbroken. These same lines, however, although protected in the more inland parts, might suffer degradation where exposed to the greater force of the waves near the mouth of the sound; but the parts differently affected would blend into each other, and so would it be with each successive beach-line; and the slope therefore, whether added to or corroded, or left untouched, would never show the traces of action on any one defined horizontal line. A little reflection will indeed show that when the water stood at the highest level, any part or point which happened to be most exposed would, from the natural slope of all mountains, be some way inland compared with the same relative point on the present coast; at all intermediate levels the waves would attack an intermediate part, either high up and more inland, or lower down and nearer the coast, so that the line (or rather zone) of greatest littoral action, joining the parts which were successively most affected, would, under the conditions of the hypothesis, be

*

An excellent summary of the argument is given by Mr. Lyell in his Elements of Geology, chap. v. [Lyell 1838.]

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inclined with the horizon either more or less, according to the original inclination of the land. Lastly, the river in the valley, as it gained power from the sinking of the sea, would generally remove the central portions, and leave only a fringe of the littoral and sublittoral deposits. This fringe, although formed by successive horizontal beach-lines, would slope upwards, as the whole bottom of the valley would have done if no part had been removed. I allude to this structure more particularly, because it is not at first obvious that matter accumulated on a sea-shore would in any case form a fringe of this kind. In the hypothesis I have supposed the upward movement of the earth to have been absolutely uniform during equal periods. But this probably has seldom been the course of nature. There is clear evidence that the action of volcanos is intermittent; and the force which keeps volcanos in action being absolutely the same with that which elevates continents (as I endeavoured to prove in a paper read not long since, March 7th, 1838, before the Geological Society),8 so we must suppose that the elevation of continents is likewise intermittent,—a conclusion which receives ample confirmation from the occurrence in nature of successive lines of escarpment, rising one above another, which mark those periods of rest when the sea wore deeply into the former coast. Let us then suppose that the water stood for a longer time at some one level than at any other. The first effect would be, that the beach or delta at the head of the sound, where the river is constantly bringing down detritus, would be broader there, owing to the greater accumulation of matter during this longer period, than in any other part; and therefore when the bottom of the whole valley was converted into land, the slope, which is everywhere gentle, would in that part approach nearer to horizontality; but in other respects there would be scarcely any difference. In like manner, in those portions of the mountains, on each side of the valley, where from the protected nature of the site matter did during the whole rise accumulate, though very slowly, the line would, from the greater quantity of matter added during |60| the longer period of rest, slightly project beyond the general slope of the surface; and where any rivulet came down a very little delta would be formed. Also on any projecting or exposed point, the solid rock would be more deeply cut into than in the other lines. But as the land rose, the little deltas gently sloping from the line of ancient beach, with their front part cut off by the action of the subsiding waters, would project from the hill sides in the form of obliquely truncated buttresses; to the heads of which the horizontal lines of beach will exactly coincide, as indeed they likewise will with the broader ones, where crossing the bottom of the main valleys; but the slope in the latter case will blend both above and below with the inclined surface formed by the matter rapidly accumulated at every successive level. Now it has been shown that Scotland within modern times has undergone a great elevation; it has been shown to be extremely improbable that such movements should be equally progressive: the effects of aqueous action on the surface of the land during the intermittent periods of rest in the elevatory forces have been traced; and it will have been perceived by those who have read the early part of this paper, or the memoirs of Sir Lauder Dick and Dr. Macculloch, that the results anticipated in the hypothesis are the characteristic features, even in detail, of the “parallel roads of Lochaber”: I believe, then, that the hypothetical case gives the true theory of their origin.

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Section V.—Objections to the theory from the non-extension of the shelves, and the absence of organic remains at great heights, answered Several objections to this view, which implies that the whole country has been slowly elevated, the movements having been interrupted by as many periods of rest as there are shelves, will occur to every one. Perhaps the most important of these is, that, as the upward movement probably affected a considerable area, or at least as it cannot be supposed to have been confined within a defined line, so ought the shelves to be continuous over an equal space. I believe, however, from what I have seen in South America, that it would be more proper to consider the preservation of these ancient beaches as the anomaly, and their obliteration from meteoric agency the ordinary course of nature. Some contingencies seem absolutely necessary for the formation of the shelves, such as a sufficient height in the land, a steep slope, and that the country should be formed of rocks which afforded an abundance of somewhat adhesive detritus; we may conclude, moreover, that the surface must have been covered with turf, immediately after the waters subsided; for otherwise the loose matter would infallibly have been washed from the hills, and this contingency implies a protected, and hence, perhaps, an inland situation, which, at the period, when the water stood at the upper shelves, would leave but a small area. The abundance of detritus no doubt is quite necessary; for although the solid rock is in some parts notched, I do not believe the shelf would anywhere be distinguishable if the soil and detritus were entirely removed from it. It would also appear to be necessary that the valley should either have been originally closed at its upper end, |61| or that during the period of rest some shallow part in it should have become so from the accumulation of sediment, or from any other cause, so that no stream set through it. Thus the two upper shelves of Glen Roy die away as soon as they enter the valley of the Spean, which must at the period when the waters stood at their levels, have formed an open channel connecting opposite seas. That the ancient beaches in this case extended to that point, beyond which the accumulation of matter was prevented by too much exposure, seems clearly indicated, in a manner before explained, by the extremities of the lower shelf stretching beyond those of the upper. When, however, the 972-feet shelf existed as a beach, the channel of the Spean was converted by the closing of the pass of Muckul into a sound; and the shelf, apparently in consequence, winds along the sides of the valley both of the Spean and Roy. Besides the requisites here mentioned, the shelves appear to be more plainly marked where the valley is narrow, and, perhaps, likewise where it is tortuous. Now from the little I have seen of Scotland, I very much doubt whether these several contingencies occur frequently together; they certainly did not in several valleys which I visited. It must also be borne in mind, that as Sir Lauder Dick traced the lower shelf very much further than Macculloch had done, and as I found a remnant of one in a distinct valley, and especially as Sir David Brewster has seen shelves in two places on the Spey, the probability is that others, though perhaps obscurely developed, will yet be discovered. The irregularly shaped area, in which shelves have already been found, measures in one line twenty British miles, and in another twenty-five. Notwithstanding what I have now said, the presence of the shelves in some of the glens and their absence in others, in the district of Lochaber itself, is a very extraordinary

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circumstance. Thus in Glen Roy three lines are perfectly developed, whilst in the neighbouring one of Glen Gluoy it appears that only one exists. It is useless without data to speculate on the nature and force of the tides, currents, and winds of former periods, or on the kind of vegetation with which the land was then covered; all circumstances, perhaps, sufficient to determine the formation or preservation of a mere narrow mound of soft matter on the steep side of a mountain. But the following case proves, and it deserves particular attention, that the limits of the ancient waters cannot even approximately be inferred from the present extension of the ancient beach-lines. Macculloch has drawn in his map a shelf intermediate between the two upper ones, on the face of the mountain (Tombhran) opposite to where Glen Turet joins Glen Roy: Sir Lauder Dick has not noticed this shelf.* Perceiving its |62| importance I examined it with scrupulous care. It occurs rather nearer the lower than upper shelf, and as these two are only eighty-two feet apart, and are here strongly marked, it was scarcely possible (especially as I purposely looked at it from every point of view,) to make any mistake in the absolute parallelism of this intermediate shelf. It can be traced for nearly three quarters of a mile; at the west end disappearing quite insensibly, like the lines in Glen Collarig, but at the other end rather more abruptly in a water course. I walked along its whole length, and its structure is perfectly characteristic; I refer to the materials of which it is composed, its breadth and inclination. The two regular shelves are, perhaps, more plainly marked here than in any other part of the whole glen; and it would appear probable that this is owing to that portion having been exposed to a longer space of open water, by which means the ancient waves acquired a greater than ordinary power in heaping up detritus. In the mouth, however, of Glen Collarig and of Glen Roy, an exposure to a wider channel, but at the same time to one open at both ends, and therefore probably a tide-way, has entirely prevented the accumulation of matter; and hence the beaches gradually disappear there. This view, if correct, as I fully believe it to be, shows by what a slight difference of circumstances, either a remarkable development or an entire obliteration of the ancient beaches has been determined. The intermediate shelf clearly owes its existence to the same causes which have in this part so strongly marked the upper and lower one; and though it is less strongly marked than these two in this immediate neighbourhood, yet it differs but little from them as they ordinarily occur, and is, I think, fully as plain as the lower shelf throughout Glen Spean, I assert, then, that it is an incontestable fact, that water must have remained at the level of this intermediate shelf for a long period, and only a little less long than at the other lines; yet in no other part of Glen Roy, the valley where circumstances have been so *

Until I saw this shelf I doubted its existence, because I had not been able to discover others mentioned by Macculloch: thus one is figured by him in a ravine branching from Glen Roy (improperly called by him Glen Fintec), which, though having ascended it, I was unable to see. Again Macculloch states, that two shelves occur in Glen Gluoy, whilst Sir Lauder Dick, who seems to have examined most carefully this glen, could find only one. I may here remark, that should two shelves be hereafter discovered there at the same relative height from each other with those of Glen Roy, and this is stated to be the case by Macculloch, the fact would be highly satisfactory on the theory of the shelves having been sea-beaches. From an excellent point of view, however, on the side of Ben Erin I could see no trace of a second shelf. Macculloch also |62| figures a supernumerary shelf at a point north-west of the houses of Glen Turet, at a level above that of the upper shelf of Glen Roy; a mound of alluvium, above, and nearly parallel to the shelf, certainly occurs there; but from the want of sharpness of outline, I should be unwilling to pronounce that it had formed a line of beach, although I should be far from feeling any surprise if this could be shown to have been the case.

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pre-eminently favourable for the formation and preservation of these beaches, a trace of this intermediate shelf has been observed. It has likewise been most clearly shown, that barriers could not have existed at the double mouth of Glen Roy, and we have seen that the surface of the land has been preserved in that neighbourhood in a manner quite extraordinary; yet it is known on the authority of Sir Lauder Dick, who appears to have examined the whole course of the Spean and its tributaries with great care, that not a vestige of either of these upper shelves can be discovered beyond the mouths of Glen Roy. Any argument, therefore, whatever, from the non-existence of the shelves or beaches bearing on the former limits of the ocean over this part of Scotland, during the period of rest in the subterranean movements, is valueless. |63| In the valleys of the Spean and the Roy, I attentively examined, with the expectation of finding fragments of sea shells, the matter accumulated on the shelves, and more especially the thicker beds of gravel and sand which occur at lower levels; but I could not discover a particle, and the quarrymen assured me they had never observed any. This may at first be thought a strong objection against the theory of the marine origin of these deposits. But having been led in consequence of Mr. Murchison’s9 remarkable discovery of recent sea shells in the inland counties of Shropshire and Staffordshire, to examine many gravel pits there, and having observed how frequently it happens, that not the smallest particle can be discovered in vast accumulations of the rudely stratified matter, and that when found, the fragments are generally exceedingly few in number and partially decayed, I feel convinced that their preservation may be considered as a remarkable and not as an ordinary circumstance. After a longer interval of time, or under some slightly less favourable conditions, all the gravel beds of Shropshire, which no one can doubt were accumulated beneath the sea, would be as destitute of organic remains as those of Lochaber. In some parts of South America I have found beds of gravel which did not contain a fragment of shell, and yet on the bare surface, nearly perfect ones were strewed in numbers. Mr. Smith describes* beds on the west coast of Scotland, and Mr. Lyell† others in Sweden, undoubtedly of marine origin, but wholly destitute of organic remains. On the coast of Forfarshire also Mr. Lyell, as I am informed by him, found shells in gravel beds extending to the height of between fifty and sixty feet; but at greater altitudes similar beds occur which do not contain any: he has observed the same kind of fact strikingly illustrated in Norway.‡ It is easy to imagine

* † ‡

Edinburgh New Philosophical Journal, vol. xxv. p. 380. Transactions of the Royal Society, 1836, p. 11. and 15. Mr. Lyell has had the kindness to give me the following observations on this point. “In the country surrounding the fiord of Christiania, especially between Christiania and Dramman, and between Dramman and Holmstrand in Norway, deposits of clay and sand rest in horizontal beds on the gneiss, granite, porphyry, and other rocks. Large masses of this sand and clay reach in some places to elevations of more than 600 feet above the level of the sea, and nearly fill many upland valleys; but it is only in those patches which occur at the height of about 200 feet, and usually less than fifty feet above the sea, that shells (all of recent species) have been found. This sand and clay appear to have accumulated on the older rocks during their gradual upheaval from beneath the sea, so that greater elevation becomes a test of higher antiquity, and those patches which are found at small heights near the borders of the present fiord are very modern. Even in these last the shells are often in so advanced a state of decomposition as greatly to favour the theory that a more considerable lapse of time might be sufficient to obliterate all traces of their existence. Thus for example, on the banks of a small river about two miles above Töusberg at the place where the bridge crosses it, a section of loamy clay is laid open, the lowest part of which cannot be raised more than a few feet above the salt water of the fiord of Christiania. In the upper part of the mass for a thickness of fifteen feet no fossils can be detected, but somewhat lower faint casts of the Mytilus edulis, chiefly indicated by purple stains, are observable. Still lower down more perfect specimens of the same shell, together with

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several |64| circumstances which might determine the preservation or decay of the shells; even on the assumption, which is not necessary, that they have in all such cases been imbedded. Thus in Shropshire, the gravel is covered in most parts by an earthy deposit, which contains a small proportion of lime; hence the rain water having absorbed carbonic acid gas in its descent, would find matter to dissolve before it reached the layers containing shells; whereas in Lochaber the gravel and sand, being derived entirely from granite rocks, does not, as I ascertained, usually contain any free carbonate of lime, and consequently the fragments of shells would more readily be dissolved. I do not wish to assign this circumstance* as the real cause of their disappearance, but merely to indicate it, and other similar ones, as quite sufficient to show that the marine origin of the shelves cannot be controverted from the absence of organic remains. Section VI.—Application of the theory to some less important points of structure in the district of Lochaber, and recapitulation By considering the hypothetical case above given, I think it was shown that the proposed theory explains every essential point in the phenomenon of the parallel roads. And I will now endeavour to show how far it applies to some minor points of detail. For instance, I have described a horizontal band of rock on one side of the narrow mouth of Loch Treig, with its face worn into smooth concave forms, like those over which a water-fall rushes; and on the other side, a great spit or bank of sand and gravel. Now on the belief, that a sheet of water seven or eight miles long, and two or three broad, was drained during each ebb-tide to the depth of several feet through a narrow curved channel, and then again raised by the following tide to its former level, the effects there produced are quite intelligible. It is also easy to perceive, that through the means of the tidal action, points of solid rock might have been obliquely cut off in the same manner as on existing beaches; and that flat channels, resembling in every respect those which at present frequently separate small |65| islands from larger ones, might have been worn between hummocks (such as those on one side of Meal-derry) and the lines of shelf. If, again, we consider what must take place during the gradual rise of a group of islands, we shall have the currents endeavouring to cut down and deepen some shallow parts in the channels, as they are successively brought near the surface, but tending from the opposition

*

Cardium edule, occur, but both in so soft a state as to crumble into dust when dried. With these the more solid Cyprina islandica and Saxicava rugosa are occasionally found, and although soft when first taken from the matrix are capable when dried of being preserved entire. If in the short period which has probably passed away since these shells |64| near Töusberg were imbedded, the progress of decay can have proceeded so far, we may well suppose the percolation of water during antecedent ages of indefinite extent to have destroyed all signs of fossils in the more ancient and elevated patches of loam found more than 500 feet high in the adjacent hilly country.” I may observe that it very frequently happens, that shells are found only at some depths in these superficial deposits: this is the case in several of the gravel pits in Shropshire; in cutting the canal at the head of Loch Ness, the shells were met with at the bottom, whereas, the layers nearer the surface, as I can vouch, contain none. Mr. Smith speaking (p. 380 and 391. vol. xxv. Philosophical Journal,) of the clay beds on the west coast of Scotland, says, that the marine remains with which it abounds “are almost invariably found in the lower part of the bed.” I infer that in all these cases shells originally existed in the upper part, but have since decayed: Mr. Smith, however, offers a different explanation. In the extensive and superficial beds of elevated shells on the coast of Peru, where rain does not fall, and where consequently loose matter is not washed from the surface, I have traced as I have ascended from the beach a most perfect gradation in the decay of the shells, until a mere layer of calcareous powder, without a vestige of structure, alone remained.

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of tides to choke up others with littoral deposits. During a long interval of rest in the upward movements, from the length of time allowed to the above processes, which essentially require time (though they are favoured by the rise of the land rather than by its remaining stationary), the tendency would often prove effective both in forming by accumulation of matter, isthmuses, and in keeping open channels. Hence such isthmuses and channels just kept open, would oftener be formed at the level, which the waters held during the interval of rest, than at any one other. These isthmuses and channels when left by the receding waves, might be called land-straits, for they would present smooth, flat, narrow surfaces, connecting more open spaces. During the rise of the land they would at first separate the heads of two adjoining creeks, and afterwards, the upward movements proceeding, they would form the watersheds between adjoining and opposite glens. By this means, I explain both the ordinary structure of the land in these mountains, where the waters divide, as already described; and more especially the remarkable fact of the exact coincidence of several such points with the lines of shelves,—the shelves only indicating the long interval of rest in the upward subterranean movements. It may be remembered that I described at the head of the Roy and of the glen near Kilfinnin, patches of alluvium or remnants of terraces on the sides of the land-straits, a little above the flat where the waters divide. This structure is in perfect accordance with the theory that drift matter began to accumulate in such parts at that period, when the tides in them were first checked, or otherwise affected by the rising of the land; and that the channels were finally closed at their present levels, solely from the long interval during which the sea acted at such levels. Hence, also, we might have expected, that patches of alluvium would occur (as is the case) on the sides both of the land-straits which are, and those which are not connected with shelves at corresponding levels. From the levels taken by Mr. Maclean10 with Sir Lauder Dick, it appears that the upper limit of the Glen Gluoy shelf, which coincides with the division of the waters, is twelve feet higher than that of Glen Roy. The intervening space is nearly a mile in length, moderately broad, and very flat, having only a fall of the twelve feet; and Sir Lauder states* that he saw in this part the surface of the solid rock in the bed of the little stream. These facts seem at first to indicate that two periods of rest had supervened, one when the water stood at the level of the Glen Gluoy shelf, a second when at the upper level of Glen Roy after a rise of twelve feet, and that, nevertheless, the effects of these two periods of rest were confined respectively to separate, though closely adjoining glens. This circumstance if so interpreted, although improbable in |66| the highest degree, could not be considered as subversive of the theory, after it has been ascertained that the upper shelves of Glen Roy are not prolonged into the valley of the Spean, and that the short intermediate one in Glen Roy does not extend for more than three quarters of a mile in that valley. There is, however, I suspect a more satisfactory explanation. In the First Narrow of the Strait of Magellan, the tide rises about forty feet, as Captain FitzRoy informs me, whilst eighteen miles to the west at Gregory Bay, the rise is only about twenty feet. Here then, and other instances might be adduced, in a distance of eighteen miles, the surface of the water must slope no less than twenty feet. Let *

Edinburgh Transactions, vol. ix. p. 35.

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us suppose a rocky barrier (and that of Glen Gluoy is rocky) to be elevated, by such movements as those now in progress in South America, across the strait, separating it into two portions. Might we not expect that the high water mark would rise several feet higher, in that portion of the former channel which was still open to the sea subject to the great tidal movement, than it would in the other connected only by tortuous passages with a different sea, where the rise of the tide was small? In such a labyrinth of channels as this part of Scotland must have presented when the sea stood at the level of the upper shelves, it is even probable that there would be inequalities in the rise of the tide in different parts; I conclude therefore that when the rocky barrier was upraised between Glen Gluoy and Glen Roy, a greater tide-wave, proceeding direct from the line of the Caledonian Canal, then a great strait, swept up this deep creek; whereas a smaller one reached by a circuitous course the Bay of Glen Roy, which, moreover, was connected by some other straits with the eastern sea. Whoever walks over these mountains, and believes that each part has been successively occupied by the subsiding waters of the sea, will understand many trifling appearances, which otherwise, I believe, are unintelligible. Thus in Upper Glen Roy he will see in the level expanse, an old bay, filled up and leveled with tidal mud. Again at the Gap of Glen Collarig, with its flat bottom and cut off sides like a gateway, he will recognise a channel, at last choked up with matter drifted by the tides, and now left in the state in which it was when the waters retired from it. The traces of supernumerary shelves will offer no perplexity to him, and will equally receive with the others a simple explanation. By the theory of the sea having acted at successive levels over the whole surface of the land, the great beds of shingle* and sand, |67| such as those near the mouth of the Spean, have a cause assigned to them adequate to the effect. Lastly, the manner in which the deposits near the mouths of the larger valleys have been modeled into successive terraces, which in some parts at least appear not to have been formed by the river, receives elucidation. I may add, that in South America I have observed numerous instances of terraces in every respect similar to these, with sea shells abundantly scattered on their surface; and therefore where there could exist no obscurity regarding their origin. In concluding this part of my paper I will recapitulate the course of the argument pursued. 1st. It is admitted by every one that the horizontal shelves are ancient beaches. 2nd. I showed that no lake theory could be admitted on account of the overwhelming difficulties in *

I have before alluded to the fewness of the well-rounded pebbles near the upper shelves, excepting at the heads of the valleys, or on flat places. This is a difficulty; though it is one common to many regions, where we know that much denudation has taken place at some period or at another. Pebbles of most rocks may in the course of time decay, but those of quartz I should think (although Scoresby says this rock yields to the frosts of Spitzbergen) [William Scoresby (1789–1857), clergyman and scientific voyager. Scoresby 1820.] would be imperishable: if so, how comes it that quartz pebbles are not scattered over the surface of every mountain in which that rock is present, and in which the form of the land, its denuded state, or the presence of truncated dikes show that it must once, although perhaps countless ages since, have been beaten by the waves of the sea? Such pebbles, however, are not found on every mountain thus circumstanced: the explanation, I presume, rests in this; that every cause of disturbance, wind, rain, earthquakes and the fall of fragments all tend to move the pebbles in one direction alone, namely downwards. I am inclined to believe this view is |67| correct, and that in the course of time, such pebbles are all rolled down, from having found on an isolated mountain of quartz in South America (the Sierra Ventana) a superficial patch of conglomerate, like part of an old beach, which seemed solely to owe its preservation to the pebbles having been cemented to the parent rock by oxide of iron, in the same manner as not unfrequently may be observed on some existing sea beaches. In the case of the shelves of Lochaber, it is probable, that only a few pebbles were originally formed, owing to the small power of the waves on the steep and protected shores of these ancient sounds.

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imagining the construction and removal at successive periods of several barriers of immense size, whether placed at the mouths of the separate glens, or at more distant points. 3rd. The alternative that the beaches, if not formed by lakes, must of necessity have been so by channels of the sea, was not advanced, only because it was thought more satisfactory to prove from independent phenomena, that a sheet of water gradually subsiding from the height of the upper shelves to the present level of the sea, occupied for long periods not only the glens of Lochaber, but the greater number, if not all the valleys of this part of Scotland; and that this water must have been the water of the sea. 4th. It was stated (the strongest argument being the ascertained fact of the land rising at the same time in one part and sinking in another,) that in all cases the land is the chief fluctuating element; and, therefore, that the above change of level in Scotland, independently attested by marine remains at considerable heights on both the eastern and western coasts, implies the elevation of the land, and not the subsidence of the surrounding waters. 5th. It was shown that in all such prolonged upward movements it might be predicted, that there would be intervals of rest in the action of the subterranean impulses. 6th. By an hypothetical case, the land was subjected to the above conditions, and its surface was found to be modeled in a manner wholly similar, even in detail, to the structure of the valleys of Lochaber as they now exist. 7th. The true theory being considered thus established, objections to it from the non-extension of the shelves, and from the absence of organic remains at great altitudes, were answered and shown not to be valid. 8th. Many points of detail in the structure of the glens of Lochaber, were shown to be easily explicable on the supposition, that the valleys had been occupied by arms of a sea subject to tides, and which had gradually subsided during the rising of the land. Having attentively considered these several and |68| independent steps of the argument, the theory of the marine origin of the “parallel roads of Lochaber” appears to me demonstrated. I may here remark, that Macculloch seems to have been aware of the great difficulties attending his theory: but having proved that the roads could not be works of art, or the effects of any great debacle, he argued, to use his expression from the dilemma of the case, that they must have been formed on the shores of a lake. The idea of a continent slowly emerging from beneath the sea, appears, and it is a very curious point in the history of geology, never to have occurred to him as a possibility, although he was so bold and ingenious a speculator. His paper was read in the beginning of 1817, and when we reflect that during the few latter years, proofs of such movements have accumulated from all quarters of the world, we must recognise how much of this all important change (the foundation-stone, I may add, of this paper) is due to the Principles of Geology by Mr. Lyell.11 Section VII.—On the erratic boulders of Lochaber I will now pass on to some other considerations which partly derive their interest as dependent on the truth of the foregoing theory. I have said, that the parent rock of many of the fragments lying on the shelves is not found in the immediate neighbourhood. These erratic boulders are generally of granite, and are from one to five and six feet in diameter; they are not confined to the shelves, but are scattered on the sides of the mountains. On the summit of the insulated hill of Meal-derry, above the level of the 972-feet shelf, there was

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one of large size, together with some well-rounded pebbles of rocks, which, I believe, do not occur there. In the gap of Glen Collarig the boulders on and near the upper shelves are frequent, as they likewise are in the pass between Upper and Lower Glen Roy; they occur also abundantly at the bottom of the latter valley, and on the side of Tombhran. From having found them in almost every part which I examined, I have little doubt that they are distributed in numbers over all the valleys and mountains, at least, to an elevation as great as that of the upper shelves: I make this latter restriction, because having ascended the mountains only in a few places above that level, I cannot speak positively with respect to the greater heights. On the mountains, however, between Glen Roy and Glen Gluoy on a hillock north-north-west (magnetic) of the summit of Ben Erin, I found several masses of granite, one of which was four feet by three in width and two in thickness (together with a couple of pebbles from rocks not in situ) resting on the surface of the gneiss. This hillock seemed to be entirely composed of the latter rock, and it was separated from all other hills by a valley. On the flanks of Ben Erin at about the same level, there were several boulders of granite, one of which was six feet across. Of those on the hillock (probably there were many others which I did not see in merely crossing the mountain,) the highest one was found by comparison with the Glen Gluoy shelf (by means of the barometer), to be 2200 feet above the level of the sea. I will describe in detail the spot where I found one other boulder, |69| in as much as the whole of the district being composed of gneiss, it might be suspected that patches of granite occurred high up on the slopes of the mountains, and that the fragments had simply rolled down into their present positions. This, however, could not have happened in the case last described, nor in the following one: about twenty feet below the summit of a very sharp peak (1600 to 1700 above the sea) the whole of which consisted of tortuous layers of gneiss, there was a block of syenite with pink felspar, two feet eight inches across. The peak is wholly separated (as shown in the wood-cut, fig. 4.) from a lofty mountain also of gneiss, by a broad and quite flat valley, the highest part of which is 215 below the spot where the boulder lay. I may observe that I did not anywhere see another boulder of the syenite, nor a single one of granite on this side of the mountains, which is separated by a lofty ridge from the valleys of Glen Roy and Glen Gluoy, where the blocks of granite are so numerous. Between two branches, however, of the Tarf Water (which enters Loch Ness near Fort Augustus) on the summit of a hillock of gneiss, about 1200 feet above the sea, I noticed one of granite.

78 A. B. C. D.

1839. Observations on the parallel roads of Glen Roy Lofty mountain of gneiss. A peat moss 215 feet below the boulder, dividing the waters flowing on each side round the hill C. Boulder of syenite resting on gneiss 1600 or 1700 above the sea. Habercalder in the great glen of Scotland.

The granite of all the boulders which I observed in Glen Roy, and likewise of those on Ben Erin, has a uniform character; it is subject to much disintegration, and therefore I do not doubt that the boulders were originally much larger. In Macculloch’s Geological Map of Scotland, the nearest granite in situ to the boulders on Ben Erin is seen to be at the source of the Roy, near Loch Spey, a distance in a north-east line, passing over mountain and valley, of between five and six miles. The granite there has the same lithological character with that of the boulders, and I do not doubt that it is the parent rock, at least, of those strewed along the course of the Roy. With respect to the boulders on Ben Erin, they are completely cut off from every granitic district by valleys, the highest point of which is 920 feet below that boulder, the altitude of which I measured; that is, it would be impossible to walk from granite in situ to these boulders without ascending at least that number of feet. |70| I will only further add, that if a sheet of water were raised to the level of the Ben Erin boulders, there would be a line of open communication* between them and the granite of Loch Spey; although I must confess I much doubt whether in that case any of the rock in situ at Loch Spey would remain uncovered; and if so the origin of the boulders must be more remote. The other tracts, where granite is represented in Macculloch’s map, are more distant, and are separated by deeper and broader valleys from the points in question. From my limited examination of the district of Lochaber I am unwilling to generalize respecting the position of the boulders, but I think that they certainly occur most frequently on the summits of little peaks, such as on Meal-derry, or on that one of which a wood-cut has been given; and perhaps likewise in the narrowest parts of the valleys; for instance at the junction between Upper and Lower Glen Roy. I observed also a greater number on the shelves than I should have anticipated, from some of those, which had originally stood higher, having rolled down. But, I repeat, I will not positively say that such is the case; although with respect to the boulders on the peaks, as I observed five well-marked cases, even during my short examination of the country, I have little or no doubt that the observation is correct. On any conceivable theory of the transportation of erratic blocks, whether by some overwhelming debacle, or by floating ice, or any other means, it will at once be evident that they must have been scattered over the country, either before the shelves were formed, or at the time of their formation, but not on account of the delicacy of the lines at any after period. According to the generally received opinion of geologists, the so-called “erratic block period” is recent, and therefore we obtain a rude method of estimating the age of the

*

This is a similar fact to what has been observed on the Jura. Sir James Hall (Edinburgh Royal Transactions, vol. vii. p. 143.) says “it is principally where the snowy summits are visible from the face of the Jura by means of some depression in the intervening hills, that we find these travelled masses.” [James Hall (1761–1832), geologist, chemist and advocate of the geological theories of James Hutton. Hall 1815.]

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shelves, and consequently of the elevation of the whole central part of Scotland, at least to a height of 1278 feet (or that of the upper shelf) above the sea. It may perhaps be worth while briefly to compare together, under the conditions here afforded, the two theories of the transportation of erratic boulders, which are alone worthy of consideration, namely, that of great debacles and of floating ice. I will not lay any stress on the difficulty of imagining, in accordance with the first theory, a rush of water so impetuous as to transport vast masses of rock across profound valleys and up the steep sides of high mountains, for this difficulty has no special reference to the case of Lochaber; but those who believe in the past occurrence of so terrific an agitation of the waters of a deep sea, must in some manner account for the frequency of boulders in the most exposed places on the summits of hillocks, and likewise for so many having been left in narrow straits, where one would have anticipated the most impetuous rush of water. On the face of Tombhran I observed many boulders scattered on the shelves, which have been formed there not |71| only by the accumulation of loose matter, but also by the deep excision of the solid underlying rock. Again, there were other boulders on the shelves on the rocky peninsula near the junction of Upper and Lower Glen Roy, where much of the gneiss has been worn away. Here it was not possible, from the non-existence of higher land, that the boulders could have rolled into their present places from above, after the formation of the shelves; nor was this at all probable in several parts of Tombhran. On the supposition of the boulders having been originally scattered over the country, and the shelves formed at a subsequent period, we have the difficulty, though perhaps not an insuperable one, as we do not know their original size, of believing that blocks of granite have been preserved for a long period on those very places, where a zone of gneiss had been cut into and worn away. Some of the boulders on Tombhran were lying on the surface of the lower edge of the shelves, in parts where, as above said, I fully believe the inclination of the ground was so trifling that it was impossible they could have rolled down from above; but I regret much that I omitted, from not having perceived its importance, to ascertain this point with certainty. If the fact be so, and I scarcely doubt it, it would prove that some action, so quiet as not to have disturbed the small quantity of earth and little stones, of which the shelves are formed, transported these boulders across deep arms of the sea, and left them on the surface of the ancient beaches. The theory, that all erratic blocks, circumstanced like these of Lochaber, have been transported by floating ice, wholly removes these difficulties; for the icebergs,12 in the first place, would generally land the fragments, with which they were charged, on the lower part of the beaches or shelves; and secondly, those which had arrived not long before a fresh elevation would have been exposed only to a small amount of tidal degradation. Thirdly, the icebergs would frequently be stranded on shoals and islets, over and round which the tides swept; and likewise they would be frequently driven on shore in the narrow parts of the channels, where the waters were pent up. So that in after times, when the land was drained, it is easy to perceive that the boulders would lie scattered in such places, as they now actually occupy in the district of Lochaber. Lastly, this theory requires that every district where boulders are found should have been covered by the sea; here we have independent proofs that such was the case, at least to an elevation of 1278 feet.

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In my Journal during the voyage of the Beagle, I have endeavoured to show that the erratic blocks of central Europe were probably transported at that period,* when |72| its climate was more equable (chiefly consequent on the larger area of water), which favours a low limit of the snow line, and therefore the probability of glaciers, the parents of icebergs, descending in favourable places into the sea. It is therefore to this period, if this view be correct, that we must refer the “parallel roads of Lochaber,” and consequently the elevation of the land, not only of the 1278-feet portion (which it is certain has been elevated at an epoch not distant), but likewise of the whole altitude, whatever it may be, at which boulders occur. If there be others, as is most probable, at a greater height than that one on Ben Erin, which I observed in merely crossing the mountains at a point 2200 feet above the sea, then by so much the greater has the elevation of the land been within this same period. Mr. Blackadder (in a letter to Mr. Lyell) states he has seen on the west coast of Scotland, in the island of Mull, large fragments of quartz rock at the height of 2000 feet, of the same description as that found on some of the adjoining islands and mainland. In Sweden M. Sefström13 says that boulders occur at an elevation of 1500 feet; in Massachussets, in North America, they are found, according to Professor Hitchcock,14 at 3000; and on the Jura it is well known they occur, from low down, to an altitude of 4000 feet. It is interesting to discover, that in our own country the upward movements, within the same period, have been more than half as great as those which have affected the latter colossal chain. But regarding the exact period, allowance must be made, since on the one hand the glaciers of the Alps, situated ten degrees nearer the equator than those on the mountains of Lochaber, must have much earlier retreated upwards, and failed in descending to the level of the sea, during the change from the former to the present climate; whilst, on the other hand, to counteract the equatorial influence, they were appendages on a greater mass of snow accumulated on far loftier chains. Section VIII.—On the small amount of alluvial action since the formation of the shelves I now pass on to another consideration. Macculloch was much struck with the fact, that in many cases where a shelf crossed a rivulet, I mean one of those silver-like threads of water *

I refer, of course, only to the more temperate and central parts of Europe, but it appears that boulders are sometimes transported in these regions, even at the present time. Sir James Hall, in his Memoir on the “Revolutions which have affected the surface of the earth” (Edinburgh Transactions of the Royal Society, vol. vii. p. 157.), states that in the Solway Firth [Moray Firth] (and therefore in salt water) “a large block of stone, four or five feet in diameter, lying within high-water mark, and well known as having served as the boundary of two estates, was during a stormy night in winter transported ninety yards, and the persons on the spot were convinced that this migration was performed by means of a large cake of ice; formed round the stone, and attached to it, and that the whole had been lifted and carried forward by the rising tide. The course of this stone was |72| marked upon the sand below by a deep and broad furrow, which remained visible for a long time afterwards, as I have been informed by several members of the Society, who saw it after an interval of more than a year.” I presume from the position of the stone as a land-mark, and from the distance it was transported by the rising tide, that the furrow left by its passage must have been either oblique or parallel to the shore. What would have been the effect if this large and heavy block had been pushed over a surface of solid rock instead of sand? This question will recall to the mind of those who have read the late papers of Messrs. Charpentier, Venetz, and Agassiz, the case of the longitudinally and obliquely scratched rocks of the Alps. [Jean de Charpentier (1786–1855), German-Swiss geologist who studied Swiss glaciers. Ignaz Venetz (1788–1859), Swiss engineer, naturalist, and glaciologist. He was one of the first to propose glaciers as a major force in shaping the earth. Jean Louis Rodolphe Agassiz (1807–73), Swiss-born American zoologist, glaciologist, and geologist. He would later become a great opponent of CD’s evolutionary views.] In the Addenda to my Journal during the voyage of the Beagle, I have endeavoured to show that the passage of ice, with imbedded fragments of rock, acting at successive levels on the surface of shoals during the gradual rising of the land, offers the most probable explanation of the scratches and grooves, which have justly excited so much attention in Scotland and other places.

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which descend the flanks of steep mountains in nearly straight |73| lines, it frequently entered a little way on each side of the gully. From this fact it is evident that the gully must have been partly formed before or at the time when the shelves were sea-beaches. I particularly observed several instances of this structure. One which struck me most was in Glen Roy, opposite a gap in the mountain which leads to Glen Fintec; here two small threads of water were united at the point where the line of shelf crossed them, and at their junction the rock was much exposed, so that any one would have supposed that the furrow in which they flowed had been entirely hollowed out by their action. But the shelf curved in a little way on each side; and, what was more curious, the apex of turf above the point of junction of the two streamlets had evidently originally formed part of the shelf. By this it was shown that the entire hollow, with the exception of the actual beds of the streams, must have existed as an indentation or little cove on the line of ancient sea-beach. It appeared to me that the extent to which the shelves entered these furrows did not bear any close relation to the power of the streamlets now flowing in them: thus on Tombhran (in front of the houses of Roy) a great gorge which is impassable, and where the rock is bare and shattered, has been deeply cut into by the winter torrents, and yet the shelves enter only a very little way on each side; whereas in other cases we find a hollow or creek of some size, but with an insignificant stream flowing in it, for instance, that opposite the gap of Glen Fintec, which has not even removed the remnants of the shelf from the head of the gully, in which it has flowed ever since the retreat of the sea. Without entering here into a full consideration how these gullies were originally formed, and whether the indentations made in the beach at one level might not be produced downwards to another, I will only remark, that the sea in most situations certainly does alter the form of its coast, and yet that an accurate map of any shore gives a line indented in such manner, that a series of them, if placed one above and a little behind another, would produce the same kind of furrowed surface which characterizes the mountains of Lochaber, as well as most others. I will further observe, that when travelling along the shores of northern Chile and Peru, where the alluvial action is reduced to an exceedingly small measure, and where it is not probable that within a recent period there has been any great change of climate, I was repeatedly much surprised at observing how absolutely similar all the minor inequalities of the surface (yet covered with beds of sea shells of existing species) were to those of countries, where almost every detail in outline is usually attributed to meteoric agency; I could perceive only one difference, namely, that the larger valleys had unusually flat bottoms. Although fully convinced of the truth of this fact, I confess I was astonished at discovering in the mountains of Scotland, which have been exposed during a vast period to the destroying action of a wet and boisterous climate, clear proofs that almost every furrow and inequality has been left nearly in the state in which we now see it,* by the retiring waves *

It is scarcely possible to convey by language any accurate idea of the kind of inequalities which, from the |74| shelves passing over them and into the intervening hollows, we know were so left by the sea. I hope any one who feels interested on this subject, will carefully examine the plates accompanying Sir Lauder Dick’s paper (Edinburgh Transactions, vol. ix.), and especially Plate IV. The shelves on the left side (looking up the glen) bend into all the principal gullies; and on the right side, directly in front of the foreground, by looking close at the plate they will be seen to curve a little way into each of the perpendicular furrows (some thinning out and others commencing), the bottoms of which have evidently been much deepened by the descending streamlets.

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of the sea. From the preservation of |74| some of these beaches, one can point to the very spot, and declare so much was removed when the sea stood there, and so much since by the running streams of fresh water. It may be asked, has the present alluvial action done nothing here? Something it assuredly has done, but I repeat, comparatively nothing to that which was effected before the sea retreated. In Chile I concluded that the action of the more rapid rivers and torrents was chiefly confined to removing the littoral and sublittoral deposits left by the arms of the sea; and secondarily in cutting, as soon as the upper beds were removed, a wall-sided gorge through the solid rock. It appeared, that as long as the river had its passage through the water-worn materials, from the great facility with which it changed its course, its bed was broad, but as soon as it reached the solid strata it became exceedingly narrow. These conclusions are in strict conformity with what I observed in the glens of Lochaber. Of the small amount of corrosion effected since the sea stood at a level of the upper shelves, there are some curious instances. Sir Lauder Dick, in describing in detail the head of Glen Gluoy,* concludes that the river has worn there, during the immense period which must have elapsed since the water (of the sea) retired from the 1278-feet shelf, a remarkable chasm, between fifty and sixty feet in depth, but only a few feet wide. The stream in the northern arm of Glen Turet has cut for itself a passage in the solid rock in only a part of the valley, between the middle and the 972-feet shelf. In Upper Glen Roy the southern stream falls into the plain by a cascade, to the upper edge of which on each side the 1226 shelf approaches close. I did not ascend the spot, but as far as I could judge, the water has not cut back more than at most a few yards, into the rock over which it falls. Other similar instances might be adduced. Although none of these streams form great bodies of water, yet when flooded by the winter rains they cannot be inconsiderable; and their action has been prolonged for so vast a period, that the geographical features, together probably with the climate of the country, |75| have been greatly changed. The rocky crests of the mountains no doubt have suffered from the weather; but the perfection of the shelves over spaces many hundred yards in length, and in the case of Glen Roy (where the three shelves occur) of some hundred feet in vertical height, clearly proves that as the sea left the greater part of the surface, so does it now remain. Amongst mountains the bursting of temporary lakes may sweep away or accumulate vast quantities of rubbish in the valleys; earthquakes may hurl down piles of fragments; and torrents during the lapse of ages, or under favourable conditions (such as the descent of many pebbles), may excavate a gorge of almost any depth, but which, as far as it is possible to judge, will always be narrow and steep-sided. All this must often have happened, and will so again; but the glens of Lochaber plainly show that the effects of ordinary alluvial action is exceedingly small, far smaller than any one would have anticipated. And as their outline

*

The idea given by these plates of the state of surface in these mountains, and of the manner in which the shelves bend round the headlands and enter the gullies, appears to me exceedingly faithful; although the glen itself, as represented, is too narrow and profound, and the sides much too steep. To view this Plate is a lesson full of instruction to the geologist, for he will scarcely fail to be astonished when he sees that the drawing is characteristic of any ordinary valley in a mountainous country, and at the same time to find himself compelled to admit, that even the little furrows, which it might be thought had been formed but yesterday, must have owed their origin, at least in great part, to the successive coves or indentations, continued one below another on ancient seabeaches. Edinburgh Transactions, vol. ix. p. 26.

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does not differ in any marked degree from that of all other valleys, this conclusion may be extended to other cases. In Glen Roy, where the three shelves can be seen near each other, little or no difference can be perceived in their state of preservation; indeed the upper one, I think, is more perfect than the one below it. From this fact an argument has been advanced by Dr. Macculloch, that no long interval of time could have elapsed between their formation. But this view is quite inadmissible; either the worn and deeply notched rock of the shelves on Tombhran, or the buttresses on the middle shelf (as at the head of Lower Glen Roy), which are composed of large masses of well-rounded shingle, is sufficient, without considering the intermediate shelf and other appearances, to prove that the water must have remained at levels intermediate between the highest and the 972-feet shelf for very long periods. Hence the alternative is obvious, and is in direct accordance with what has already been advanced, namely, that the ordinary alluvial action is so exceedingly small, that whether the surface has been exposed during one, two or more whole epochs, no sensible difference can be perceived in the state of its conservation. Of the many remarkable features in the geology of this district, few, perhaps, are more remarkable than this perfect preservation of its surface. We have a mound composed of soft materials so small, that it oftentimes cannot be distinguished, by a person standing on it, from the adjoining slope, but which it is not probable, from the structure of the mountains, was ever much larger; and yet this very mound, when viewed from a distance, will be seen to extend for many hundred yards, even miles, continuous and perfect, with the exception, perhaps, of a few small breaks, where some streamlet descends. On these same mounds we can sometimes distinguish those fragments which have been washed by the little waves of the ancient waters, from others which have since fallen; and at Loch Treig, at the height of 972 feet above the sea, the tide-scooped rocks appear as if scarcely a century had elapsed since they were washed by the ripple of the eddying currents. The preservation of the druidical mounds in Britain has often been adduced as a circumstance worthy of attention; |76| but here during a period which cannot be reckoned by thousands of years, but only by those great revolutions of nature which are the effects of slow and scarcely sensible changes, works smaller than those ancient ones dedicated to superstition, retain each outline nearly as perfect as when first formed by the hand of nature. These facts are interesting under another point of view, for they prove to us that we may trust the plain inference of our experiences. Although we see* the stone of many ancient buildings decaying and crumbling away, yet we know that others, as the obelisks of Egypt, have lasted more than three thousand years, with the hieroglyphics nearly perfect on them: now we cannot see any reason why their general outline, even in points of detail, should not last a hundred times three thousand years. Again, although we might expect the crest of a mountain range to be shattered, and the bed of a torrent to be worn down more or less deeply, yet if we look at a convex slope of soil clothed with turf, and drained on each side by rivulets, we can see no reason, as long as the vegetation is persistent, why such a slope (with the *

Consult Professor Phillips’s interesting paper on this subject. Geological Proceedings, vol. i. p. 323. April, 1831. [Phillips 1831.]

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exception of any spot where a waterspout might burst, or a stroke of lightning fall) should not last for as many thousand centuries as the obelisks of Egypt shall remain entire. Of the justice of these inferences, conclusive evidence is afforded by the state in which we now see the mountains of Lochaber,—a state of which we approximately know the high antiquity. Section IX.—On the horizontality of the shelves, and on the equable action of the elevatory forces Sir Lauder Dick, with Mr. Maclean’s assistance, seems to have determined within very small limits the absolute horizontality of the several shelves. A delicate eighteen-inch levelling instrument, made by Jones,15 was employed. Sir Lauder says,* “Directing the object-glass of the instrument to the nearer, and immediately opposite corresponding line of shelf, it applied all along most accurately to the horizontal hair; but when pointed to those further off (some of which were perhaps five or six miles distant), they appeared to sink sensibly below the hair, and this in proportion to their distance from the point where we stood; but they were nowhere observed to do so in a greater ratio than the allowance for the curvature of the earth at such rectilineal distances demanded. And, what was in our opinion most conclusive, when the telescope was pointed to, and made to traverse along any particular portion, which, from being directly opposite to the eye, might have been presumed to be nearly equidistant in all its parts, it was found to preserve an uniform relation to the horizontal hair.” The same results were obtained in other instances; but yet the angle of depression of the distant shelves does not appear to have been actually measured, and its correspondence with the curve of the earth calculated. But it is quite certain that if any |77| difference from that curve exists, it must be very small.† Here then is a case which supports apparently with more weight than perhaps any one hitherto advanced, the doctrine that the land is the stationary element in these changes of level, and the ocean the fluctuating one; for it may well be asked, can we suppose that a whole country shall have been lifted up without the smallest ascertained flexure of the ancient coast lines? Without reverting to the argument of the movements now in progress, some upwards and some downwards, or to the difficulty of imagining a receptacle for a stratum of water, nearly 1300 feet thick, concentric with the globe, I will consider the phenomenon in another point of view. It appears from the facts given by Mr. Lyell in his Principles of Geology,‡ and in the Philosophical Transactions,§ that a large territory in Sweden is now rising at the rate of three feet in a century; and that the area affected reaches from Gottenburgh to Torneo, and thence to North Cape (a distance of 1000 geographical miles), although the rate of elevation increases as we proceed northward. We may therefore safely conclude, that large spaces in Scandinavia have been elevated so

* †

‡ §

Edinburgh Transactions, vol. ix. p. 8. I may here remark, that the equal elevation of the west coast of Scotland, and indeed of the whole British Islands and other parts of Europe, may be inferred from the facts collected by Mr. Smith in his paper in the Edinburgh New Philosophical Journal. This author says (vol. xxv. p. 388.), “The great terrace (known to be of marine origin from the presence of organic remains), the base of which seems very generally to be between thirty and forty feet above the sea, forms a marked feature in the scenery of the west of Scotland.” Book II. chap. xvii. On the gradual rise of the land in Sweden. Transactions of the Royal Society, Part I. 1835, p. 33. [Lyell 1835b.]

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equably, that at points several miles, if not leagues apart, the difference of elevation at the close of the past century, did not amount to one foot. In South America the whole coast of Chile has been elevated within the recent period; and during the great convulsions which affect that country, large spaces have been uplifted nearly to the same amount, although some parts a few feet more than others. On the eastern side of the same continent, the land has also risen within the same period, and as earthquakes are unknown there, the change probably has been, as in Sweden, so slow as to be insensible at any one time. On that side the traveller may ride for many hundred miles over plains, scarcely broken by a single undulation, and where the strata and surface are almost absolutely level: no one would there for one moment imagine that the elevatory forces had acted unequally, but rather he is astonished that the bottom of any sea or estuary should have been so uniform, as must have been that of which the plains of La Plata not long since formed the bed. If then great plains and mountainous countries can be raised within such small limits of absolute horizontality, as undoubtedly has happened in the above cases, shall we, who are wholly ignorant of the mechanism of these movements, be justified in rejecting the plainest analogies, in supposing difficulties little short of physical impossibilities, and in believing that the reverse of what is ascertained in other cases has taken place in Lochaber, and all simply because the change of level has been |78| more equable, than we in our ignorance could have anticipated? Every one, I think, who will attentively consider the above facts, will answer with me in the negative, marvellous though the fact be, that the beaches of Lochaber, raised on high so many hundred feet, should still follow the curvature of their ancient waters. On the contrary, a most important geological fact is established; namely that an area (twenty miles in length and eighteen broad, and perhaps more, if the shelves on the banks of the Spey be included in it) has been raised 1278 feet above the level of the sea, so equably, that no deviation from the true curvature of the earth can be discovered by the ordinary means of leveling.* Section X.—Speculations on the action of the elevatory forces, and conclusion If we choose to enter on speculative grounds and to reflect on the secondary means which have caused these equable movements, two solutions occur. But first I must remark that the crust of the earth seems to yield easily to the forces which have acted on it from below; when we observe a brick-wall dashed to pieces by a cannon ball, or a pane of glass by a small stone, we say that both are fragile and yield easily; so when we examine the earth and find it fissured and refissured, one fragment let down and another raised high up (as we know to be the case where extensive sections have been obtained, as in our coal-pits or metalliferous districts), we must certainly admit, that the force which has broken up the crust in vertical planes relatively nearer to each other, compared with its thickness, than in the fissured pane of glass, easily overcame the resistance offered to it, however absolutely great that may have been. This same conclusion is forced on us, when we reflect that the very cause of the trembling of the ground in earthquakes seems due to the rending of the strata; and that *

Considering the great importance of this conclusion, and the many points of interest connected with the subject of the ‘parallel roads’ it is greatly to be desired that the admirable opportunity for a close examination, afforded by the intended Ordnance Survey, will be taken advantage of by the gentlemen, so well qualified for the task, who conduct it.

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earthquakes in many countries are of such frequent occurrence, that probably this hour will scarcely elapse without the crust somewhere yielding. If indeed the crust did not yield readily, partial elevations could not be so gradual as they are known to be, but they would assume the character of explosions. That there has been some real connexion in certain cases* between that state of the weather which is accompanied by a low barometer and the occurrence of earthquakes, can, I think, hardly be doubted; if we admit Mr. P. Scrope’s16 explanation of this, that the diminution of atmospheric pressure (equal in some cases to an inch and half of mercury, spread over a very large area) determines the particular time at which the earthquake occurs, the force and tension being before almost balanced, we may be said to possess a rude measure of the force requisite in that area to overcome the coherence of the parts, as existing in the intervals of the recurrent earthquakes. If then the motive |79| force acts so gradually that the earth’s crust can acquire that degree of tension, which causes large portions of it to yield readily to a very slight additional impulse; and if, as we know undoubtedly to be the case, the crust has yielded in innumerable vertical planes, intersecting each other like a net-work, and running parallel to each other at very short distances, we are compelled to admit that the equable elevation of so large an extent of country as Lochaber, must have resulted from the equable action of the elevatory forces, and not from the cohesion of its parts. Bearing this in mind, the most obvious solution, but I very much doubt whether the correct one, is, that no force excepting the uniform expansion of solid matter from heat, could raise so equably the surface of a great fragile mass, as the district of Lochaber must be considered. I doubt this solution, first, because a very great expansion is necessary, especially if we include in these movements the elevation of the erratic blocks, now lying more than 2200 feet above the sea. Secondly, because the movements appear to have been of the same kind as those in the not distant country of Sweden; and there it has been shown by Mr. Lyell, that near Stockholm an alternate movement of more than sixty feet has taken place within the human period; and one is strongly tempted to believe that there is some relative connexion between the areas in Northern Europe which are rising and those which are quietly subsiding. These facts to be explicable on the theory of expansion, require, as it appears to me, far too capricious an action, in so slowly and far-pervading an influence as heat, to be admitted; whilst on the supposition of mechanical displacement such difficulties are not presented. Thirdly, because (and it is my chief reason for rejecting the agency of expansion by itself) the movements appear to have been of the same order with those now in progress in South America; and in that country the elevation of certain wide areas, as I endeavoured to show in a paper lately (March 7, 1838) read before the Geological Society,17 cannot be attributed to any other cause than an actual movement in the subterranean expanse of molten rock: to speak only for example sake, such as would result from a change in position of those inequalities in the ellipticity of the earth’s surface, which seem indicated by the measurements of arcs of meridians. It may also be inferred, from the facts given in that paper, that the fluidity of the nucleus must be tolerably perfect. In the volcano, even the lava which is propelled to the summit of a mountain, far beyond the subterranean isothermal line of melted *

In my Journal during the voyage of the Beagle, I have mentioned (p. 431 and 432.) some instances of this.

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rock, and poured out on the surface, is oftentimes so fluid, that it runs into thin sheets like molten metal. Also at the junction of the plutonic with the metamorphic formations, we see tortuous thread-like veins branching from the former into the latter, which could only have been injected when quite liquid. Here the rock has been melted at a great depth under an enormous pressure, and yet the fluidity must have been very perfect: such plutonic rocks moreover form the beds on which all others rest. Considering these latter facts, together with the inferences deduced from the phenomena observed in South America, it may be granted as not improbable in any high degree, that this part of Scotland when it was upraised rested |80| on matter possessed of considerable fluidity, which underwent a slow change of form. If this be granted, there is no great difficulty in conceiving that the surface of the interior molten matter might retain that degree of curvature proper to it, as the resultant of the unknown force with that of gravity and the centrifugal impulse. Moreover, as we must conclude from what we now see going on in South America and in Scandinavia, that the area affected was large, the difference between the amount of curvature of the fluid nucleus after the rise in that part of one or two thousand feet, would be exceedingly small, and its outline scarcely distinguishable from that of the ocean, and certainly not from that of a sea affected by various tides in confined channels, which in the case of Glen Roy affords the only standard of comparison. We may almost venture to say, that as the packed ice on the Polar Sea, with its hummocks and wide floes, rises over the tidal wave, so did the earth’s crust with its mountains and plains rise on the convex surfaces of molten rock, under the influence of the great secular changes then in progress. After these considerations I am far from thinking it an overwhelming difficulty, that the curvature of the shelves of Glen Roy over a space of four, or five, or perhaps even twenty miles should appear to be the same with that of the surface of the ocean, within that limit of accuracy which the nature of the case renders possible. On the contrary, I deduce from their curvature, first, that the district of Lochaber formed only a small part of the area affected; secondly, a confirmation of the view, which I deduced from the phenomena observed in South America, that the motive power in such cases is a slight additional convexity slowly added to the fluid nucleus; and thirdly, this additional fact, that we thus obtain some measure of the degree of homogeneous fluidity of the subterranean matter beneath a large area, namely, that its particles, when acted on by a disturbing force, arrange themselves in obedience to the law of gravity. And although we arrive at this conclusion with some surprise, when relating to the abysses of the nether regions, we see it habitually verified in volcanic countries, where a torrent of lava, checked by some obstacle, has expanded into a level sheet. Mr. Lyell, in his Principles of Geology,* quotes a passage from Sir John Herschel’s18 Astronomy,† to show that whatever may have been the original figure of the earth, the wearing down of the solid matter and its redeposition at the bottom of the sea, must tend continually to change the actual figure of the earth, as Playfair‡ expresses it, into the statical one: he then adds, “that the same remark applies to every stream of lava flowing on the surface, and if the * ‡

† Principles of Geology, Book II. chap, xviii. p. 311. 5th edit. Cabinet Cyclopedia. Astronomy, p. 120. Illustrations of Huttonian Theory. [John Playfair (1748–1819), mathematician and geologist who popularized the geological theories of James Hutton in Playfair 1802.]

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volcanic action should extend to great depths, so as to melt one after another different parts of the earth, the whole interior might at length be remodeled under the influence of similar changes, due to causes which may all be operating at this moment.” Now if it be granted that the curvature |81| of the shelves of Lochaber is due to the elevation of the district by means of a subterraneous expanse of fluid matter; the atoms of which obeyed the law of gravity, it cannot be doubted they would likewise obey that of the centrifugal force. Therefore, if the figure of the earth did not already very nearly approach to that of a spheroid of equilibrium, regions near the equator and others near the poles, during the changes of level now actually in progress, would be acted on by forces greatly different; and consequently as the crust does now yield (and has yielded in an infinite number of planes,) the statical form would be immediately acquired. This view is here given, because a directly opposite, and as I cannot but think incorrect one, has been advanced by Playfair.* In concluding this paper, I will briefly indicate the chief points which receive illustration from the examination of the district of Lochaber by Sir Thomas Lauder Dick, Dr. Macculloch, and myself. 1st. Nearly the whole of the waterworn materials in the valleys of this part of Scotland were left, as they now occur, by the slowly retiring waters of the sea; and the chief action of the rivers since that period has been to remove such deposits; and when this was effected, to excavate a wall-sided gorge in the solid rock. 2nd. During the vast period which must have elapsed since the sea stood at the level of the upper shelves, the alluvial action has been exceedingly small: steep slopes of turf over large spaces and the bare surface of rocks have been preserved even perfectly; and we see every main, as well as most of the lesser inequalities of the land, in the state in which they were then left. 3rd. The elevation of this part of Scotland from the level of the present beach to the height of at least 1278 feet has been extremely gradual, and was interrupted by long intervals of rest: it has taken place since the so-called “erratic block period.” 4th. It is probable that the erratic blocks were transported during the quiet formation of the shelves. One was observed to occur at an altitude of 2200 feet above the level of the sea. 5th. The extraordinary fact that a large country has been elevated to a great height so equably, that the ancient beach-lines retain the same, or nearly the same curvature, which they had when bounding the convex surface of the ancient waters. Lastly. The inferences from this head, supported by other cases, namely, that a large area must have been upraised, and that this was effected by a slight change in the convex form of the fluid matter on which the crust rests; and, therefore, that the fluidity is sufficiently perfect to allow of the atoms moving in obedience to the law of gravity, and consequently of the effects of that law modified by the centrifugal impulse. Hence, that even the disturbing forces do not tend to give to the earth a figure widely different from that of a spheroid in equilibrium. Postscript I am much indebted to my friend Mr. Albert Way19 for his kindness in lending me the drawing, from which the accompanying lithographic sketch has been taken. It very faithfully represents the general appearance of Glen Roy. *

Illustrations of the Huttonian Theory, p. 488.

[1839]. Questions about the breeding of animals

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In this paper CD argued that the parallel horizontal ledges or ‘roads’ were marine beaches raised above present day sea level by crustal uplift. He later regarded it as a great blunder on his part when it was shown that they were the shorelines of glacial lakes. See Rudwick 1974 and Herbert 2005. Thomas Lauder Dick (1784–1848), Scottish novelist and amateur geologist. Dick 1823. John MacCulloch (1773–1835), physician, chemist and geologist. He was elected to the Geological Society in 1808, and was President in 1816–17. MacCulloch 1817. The valley of the Roy River, a tributary of the Spean, near Fort William, Scotland. See Rudwick 1974. David Brewster (1781–1868), Scottish physicist who specialized in optics. Alexander Blackadder, a civil engineer from Stirling, Scotland. James Smith (1782–1867), geologist and biblical historian. Smith 1838. Darwin 1838, F1649 (p. 40). Roderick Impey Murchison (1792–1871), army officer and one of the foremost geologists of the era, president of the Geological Society of London, 1831–33 and 1841–43, president of the BAAS, 1846, president of the Royal Geographical Society of London, 1843–58 and Director-general of the Geological Survey of Great Britain, 1855. Mr. Maclean was a civil engineer who accompanied Lauder Dick. Lyell 1830–3. On Darwin and his interests in icebergs see Mills 1983. Nils Gabriel Sefström (1787–1845), Swedish chemist and mining geologist. Edward Hitchcock (1793–1864), American geologist and clergyman. W. and S. Jones, scientific instrument makers, London. George Julius Poulett-Scrope (1797–1876), geologist and political economist. Darwin 1838, F1649. (p. 40) John Frederick William Herschel (1792–1871), astronomer, mathematician, chemist and philosopher of science. Herschel 1833. Albert Way (1805–74), antiquary and traveller, a friend of CD’s from their student days in Cambridge. Way sketched the well-known student portraits of CD astride beetles.

[1839]. Questions about the breeding of animals. [London: Stewart & Murray]. F2621 1. If the cross offspring of any two races of birds or animals, be interbred, will the progeny keep as constant, as that of any established breed; or will it tend to return in appearance to either parent? Thus if a cross from the Chinese and common pig be interbred, will the offspring have a uniform character during successive generations, that is, as uniform a character, as the purebred English or Chinese ordinarily retains? Thus, again, if two mongrels, (for instance of shepherd dog and pointer) which are like each other, be crossed, will the progeny, during the succeeding generations retain the same degree of constancy and similarity, which might have been expected from pure-bred animals? Is it known by experience, that when an attempt has been made to improve any breed by a cross with another, that the offspring are apt to be uncertain in character, and that unusual care is required in matching the descendants of the half-bred among themselves, in order to keep the character of the first cross?—Always please to give as many examples as possible, to illustrate these and the following questions. 2. If by care, the character of half-bred animals (mongrels or hybrids) be preserved |2| through some two, three, or more generations, is it then generally found, that the

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[1839]. Questions about the breeding of animals

character becomes more permanent, and less care is required in matching the offspring? If this be so, how many generations do you suppose is requisite to form a mixed race, into what is ordinarily termed a permanent variety or well-bred race? Supposing some new character to appear in a male and female animal, not present in the breed before, will it become more permanent, and less likely to disappear, after it shall have been made to pass through some successive generations, by picking out and crossing those of the offspring, which happened to possess the character in question? In crossing between an old-established breed, or local variety, which from time immemorial has been characterized by certain peculiarities, or the animal in its aboriginal state, with some new breed, does the progeny in the first generation take more after one than the other? or if not so, is the character of one more indelibly impressed on the successive generations, than that of the other? Or, which is the same question, is the breed of the parents of more consequence, when a breeding animal is wanted, than when merely a fine animal is wanted in the first generation? The effect should be observed both in a female of the old race crossed by the new, and a female of the new crossed by a male of the old; for otherwise the greater or less preponderance of the peculiarities in the progeny might be attributed to the power of the sex, thus characterized in transmitting them; and not to the length of |3| time the breed had been so characterized. Thus to take an extreme example, we may presume that an Australian Dingo is an older breed than a pug-dog: if both were crossed with Spaniel bitches, would the litter in the one case more resemble the Australian, than in the other case the pug: and however this may be, would the pug, or Australian character be most persistent under similar circumstances in successive generations? How would this be in the various breeds of cattle? Thus if a Bull (or cow) of a breed which had long been known to have been white with short horns, were crossed with a black cow with long horns, (or Bull, if the first were a cow) which had accidentally sprung from some breed, not thus characterized, would there be any marked leaning in the character of the calves to either side; or would successive generations have a stronger tendency to revert to one than the other side? Please to mention in detail any instances you may be acquainted with. What would the result be, in the foregoing respects, in crossing a wild animal with a highly domesticated one of another species, supposing the half cross to be fertile? Thus if a fox and hound were crossed with pointer-bitches, what would the effect be both in the first litter and in the successive ones of the half-bred animals? To form a judgment on this latter point, the subsequent crosses in each case should be relatively the same; thus the half-bred fox and half-bred hound should be recrossed with the pointer, or with some other, but the same breed. Where very different breeds of the |4| same species are crossed, does the progeny generally take after the father or mother? When two breeds of dogs are crossed, the puppies of the same litter occasionally differ very much from each other, some resembling the bitch and some the dog. In the mule between the ass and horse, this great variation does not appear commonly to occur. Do you know any cases, where two varieties have been often crossed, and mongrels have

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been uniformly produced similar to each other within small limits, and intermediate between their parents? And on the other hand, do you know of hybrids, between such animals as are generally considered distinct species, varying in this manner? 8. When breeds extremely different (as the grey-hound and bull-dog, the pouter and fantail-pigeon,) are crossed, are their offspring equally prolific, as those from between nearer varieties (such as from the grey-hound and shepherd-dog). Is the half-bred Chinese pig as prolific as the full-bred animal? Does a slight cross increase the prolifickness of animals? 9. Do you know of instances of any character in the external appearance, constitution, temper, or instinct, appearing in half-bred animals, whether mongrels or hybrids, which would not be expected, from what is observable in the parents? 10. In those rare cases, where hybrids inter se have been productive; have the parent hybrids resembled each other; or have they been somewhat dissimilar, partaking unequally of the appearance of their |5| pure-bred parents. Also, what has been the character of the progeny of such hybrids? 11. When wild animals in captivity, cross with domesticated ones, is it most frequently effected by means of the male or female of the wild one? 12. Amongst animals (especially if in a free, or nearly free condition,) do the males show any preference, to the young, healthy, or handsome females? or is their desire quite blind? 13. Where a female has borne young to two different breeds or kinds of animals, do you know of any instances, of the last born partaking of any part of the character of the first born, and to what extent? 14. When a female of one breed has been crossed by a male of another breed several times, do the last-born offspring resemble the breed of the father, more than the firstborn, and therefore are they more valuable in those cases, where the peculiarity of the father is desired? 15. Do you know instances of any peculiarities in structure, present for the first time in an animal of any breed, being inherited by the grand-children, and not by the children? It cannot be said to be inherited without it appear in more than one of the grand-children, or without it be of an extremely singular nature; for otherwise it ought to be considered as the effect of the same circumstances, which caused it to appear in the first case. |6| 16. What are the effects of breeding in-and-in, very closely, on the males of either quadrupeds or birds? Does it weaken their passion, or virility? Does it injure the secondary male characters,—the masculine form and defensive weapons in quadrupeds, or the plumage of birds? In the female does it lessen her fertility? does it weaken her passion? By carefully picking out the individuals most different from each other, without regard to their beauty or utility, in every generation from the first, and crossing them, could the ill effects of inter-breeding be prevented or lessened? 17. Where any animal whatever (even man) has been trained to some particular way of life, which has given peculiarity of form to its body by stunting some parts and developing others, can you give any instances of the offspring inheriting it? Do you know any such case in the instincts or dispositions of animals? If an animal’s temper is

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spoilt by constant ill usage, or its courage cowed, do you believe the effect is transmitted to its offspring? Have any cases fallen under your observation, of quadrupeds (as cats or pigs, &c.) or birds (fowls, pigeons, &c.) born in this country, from a foreign stock, which inherited habits or disposition, somewhat different from those of the same variety in this country? If removed early from their parents, there are many habits, which we should be almost compelled to believe were inherited, and not learnt from them; and if transmitted to any half-breed we should feel sure of this. Can you give any detailed account of the effects on the mind, instincts or disposition |7| of the progeny, either in the first or in the succeeding generations from crossing different breeds, (for instance carrier and tumbler pigeons, grey-hounds and spaniels) or different species, (as fox and dog.) Do they show an aptness to acquire the habits of both parents? Or do they partake strongly of the habits of one side, (if so, which side?) with some peculiarity showing their hybrid origin? Or do they entirely follow one side? Can you give the history of the production in any country of any new but now permanent variety, in quadrupeds or birds, which was not simply intermediate between two established kinds? Do you know any cases of different breeds of the same species, (as of dogs &c.) being differently affected by contagious or epidemic diseases, and which difference cannot be attributed merely to a greater vigour in the one breed than in the other? In countries inhabited by two races of men, facts of this kind have been observed. All information is valuable, regarding any crosses whatever, between different wild animals, either free or in confinement, or between them and the domesticated kinds; equally so between any different breeds of the same species, especially the less known kinds, as Indian with common cattle, different races of Camels, &c. Please to state all or any particulars, for what object the cross was made and whether it is habitually made; whether the female had offspring before; whether she produced as many of the half-breed at one birth, (if more than one be produced) as she probably would have done of the pure |8| breed; whether the progeny were fertile inter se, or with their parents whether they resembled one stock more than the other and in what respects, and which; and whether the favoured side was the male or female. State, if known, whether the progeny differ when stock (A) is the father and (B) the mother, and from what it does where (A) is the father and (B) mother. If the half-bred are fertile, inter se or with the parent stock, describe the offspring whether like their parents and all like each other, or whether they revert to either original stock, or whether they assume any new character? C. Darwin. Upper Gower Street, London.

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This is the first of CD’s printed questionnaires. It was distributed between April–May 1839. He received his first dated response on 6 May 1839. The answers obtained were intended for his big book on species; they were eventually incorporated in Variation (1868). See Freeman and Gautrey 1969 and CCD2.

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1839. Note on a rock seen on an iceberg in 61° south latitude. By Charles Darwin, Esq. Journal of the Royal Geographical Society of London 9 (March): 528–9. F1652 Having been informed by Mr. Enderby,1 that a block of rock, embedded in ice, had been seen during the voyage of the schooner Eliza Scott in the Antarctic Seas, I procured through his means an interview with Mr. Macnab, one of the mates of the vessel, and I learnt from him the following facts:—On the 13th of March, when in lat. 61° S., and long. 103° 40 0 E., a black spot was seen on a distant iceberg, which, when the vessel had run within a quarter mile of it, was clearly perceived to be an irregularly-shaped but angular fragment of dark-coloured rock. It was embedded in a perpendicular face of ice, at least 20 feet above the level of the sea. That part which was visible, Mr. Macnab estimated at about 12 feet in height, and from 5 to 6 in width; the remainder (and from the dark colour of the surrounding ice, probably the greater part) of the stone was concealed. He made a rough sketch of it at the time, as represented at p. 524.2 The iceberg which carried this fragment was between 250 and 300 feet high. Mr. Macnab informs me, that on one other occasion (about a |529| week afterwards) he saw on the summit of a low, flat iceberg, a black mass, which he thinks, but will not positively assert, was a fragment of rock. He has repeatedly seen, at considerable heights on the bergs, both reddish-brown and blackish-brown ice. Mr. Macnab attributes this discolouration to the continued washing of the sea; and it seems probable that decayed ice, owing to its porous texture, would filter every impurity from the waves which broke over it. Every fact on the transportation of fragments of rock by ice is of importance, as throwing light on the problem of ‘erratic boulders,’ which has so long perplexed geologists; and the case first described possesses in some respects peculiar interest. The part of the ocean, where the iceberg was seen, is 450 miles distant from Sabrina land3 (if such land exists), and 1400 miles from any certainly known land. The tract of sea, however, due S., has not been explored; but assuming that land, if it existed there, would have been seen at some leagues distance from a vessel, and considering the southerly course which the schooner Eliza Scott pursued immediately prior to meeting with the iceberg, and that of Cook in the year 1773, it is exceedingly improbable that any land will hereafter be discovered within 100 miles of this spot. The fragment of rock must, therefore, have travelled at least thus far from its parent source; and, from being deeply embedded, it probably sailed many miles farther on before it was dropped from the iceberg in the depths of the sea, or was stranded on some distant shore. In my Journal, during the voyage of H. M. S. Beagle, I have stated (p. 282), on the authority of Captain Biscoe,4 that, during his several cruises in the Antarctic Seas, he never once saw a piece of rock in the ice. An iceberg, however, with a considerable block lying on it, was met with to the E. of South Shetland, by Mr. Sorrell5 (the former boatswain of the Beagle), when in a sealing vessel. The case, therefore, here recorded is the second; but it is in many respects much the most remarkable one. Almost every voyager in the Southern Ocean has described the

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1839. Note on a rock seen on an iceberg in 61° south latitude

extraordinary number of icebergs, their vast dimensions, and the low latitudes to which they are drifted: Horsburgh* has reported the case of several, which were seen by a ship in her passage from India, in lat. 35° 550 S. If then but one iceberg in a thousand, or in ten thousand, transports its fragment, the bottom of the Antarctic Sea, and the shores of its islands,† must already be scattered with masses of foreign rock,—the counterpart of the “erratic boulders” of the northern hemisphere.

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* †

Charles Enderby (1797–1876), a founding fellow of the Royal Geographical Society and head of the Enderby whaling and exploration shipping firm in London. In February 1839 an Enderby ship, the Tula, under John Biscoe discovered part of Antarctica, naming it Enderby Land. The sketch from p. 526 (not 524 as indicated by CD who may have cited a proof) of Enderby 1839:

The portion of the coast of Wilkes Land, Antarctica, lying between Cape Waldron and Cape Southard. John Balleny is credited with sighting land in March 1839. John Biscoe (1794–1843), Antarctic explorer. Thomas Sorrell, the only hand to serve on all three voyages of the Beagle. Philosophical Transactions, 1830, p. 117. [James Horsburgh (1762–1836), hydrographer to the East India Company, 1810–36. Horsburgh 1830.] M. Cordier, in his instructions (L’Institut, 1837, p. 283) for the voyage of the Astrolabe and Zélée, says, that the shores of South Shetland were found, by the naturalist of an American expedition in 1830, covered with great erratic boulders of granite, which were supposed to have been brought there by ice. It is highly desirable that this fact should be inquired into, if any opportunity should hereafter occur. [Pierre-Louis-Antoine Cordier (1777–1861), French geologist and mineralogist Cordier 1837.]

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1840. On the connexion of certain volcanic phenomena in South America; and on the formation of mountain chains and volcanos, as the effect of the same powers by which continents are elevated. By Charles Darwin, Esq., Sec., G.S., F.R.S. [Read 7 March] Transactions of the Geological Society of London (Ser. 2) 5 (3): 601–31, pl. 49. F16561 Contents Introduction, p. 601. Observations on the earthquake in Chile of Feb. 20th, 1835, p. 601. On the identity of the force which elevates Continents, with that which causes volcanic outbursts, p. 606. On periods of increased volcanic action affecting large areas, p. 610. Nature of the earthquakes on the coasts of South America, p. 615. On different kinds of earthquakes; and conclusions regarding those which accompany elevatory movements, p. 622. Theoretical considerations on the slow elevation of mountain chains, p. 625. Concluding remarks, p. 629.

Introduction The object of the present memoir is to describe the principal phenomena generally accompanying the earthquakes on the west coast of South America; and more especially those which attended the shock that overthrew the city of Concepcion on the morning of the 20th of February, 1835. These phenomena evince, in a remarkable manner, the intimate connexion between the volcanic and elevatory forces; and it will be attempted to deduce from this connexion, certain inferences regarding the slow formation of mountain chains. Observations on the Earthquake in Chile of Feb. 20th, 1835 This earthquake has been the subject of several published memoirs: the sixth volume of the Geographical Journal* contains an admirable account of it by Capt. Fitz Roy, R.N., in which many interesting facts are detailed, and the elevation of a large extent of coast is incontestably proved. The Philosophical |602| Transactions for 1836, also, contains a memoir on this subject by Mr. Caldcleugh.2 I must, therefore, refer to these authors, whose statements, as far as I had an opportunity of observing, I can fully corroborate, for a particular description of the earthquake itself, and of the changes of level which accompanied it in the neighbourhood of Concepcion. I will add only a few details, and will then proceed to describe the manner in which the southern volcanos of Chile were affected during the shock. The island of Juan Fernandez, situated 360 geographical miles N.E. of Concepcion, seems to have been more violently shaken than the opposite shore of the mainland, and at the same time a submarine volcano, which continued in action during the day and part of the following night, burst forth near Bacalao Head, where the depth was afterwards ascertained to be sixty-nine fathoms. This fact possesses a peculiar interest, inasmuch as during the earthquake of 1751, which utterly overthrew Concepcion, this island was likewise affected *

“Sketch of the Surveying Voyage of His Majesty’s ships Adventure and Beagle.” Vol. vi. Part II. p. 311. [FitzRoy 1836.]

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in a remarkable manner, considering its great distance from the chief seat of disturbance. If any exact record had been kept of that event, many other points of resemblance would probably have been discovered. There is a tradition, that the land was then permanently elevated, and the area affected appears to have been very much the same with that disturbed in Feb. 1835. Molina* also states, that the undulation travelled from the southward; and in this second catastrophe the inhabitants agreed in thinking that it came from S.W., or even more southerly. After an interval of only eighty-four years, it is not at all improbable that the subterranean forces should be directed towards the same identical points. Being anxious to trace the effects of the earthquake to the south, I wrote, shortly after visiting Concepcion, to Mr. Douglas, a very intelligent man, with whom I had become acquainted in the island of Chiloe; and the answer, which I have received since my return to England, is full of curious information.3 He describes the earthquake, which appears to have been felt over the whole area at almost the same minute, (as far as the clocks of the country can be relied on,) as being very violent. He says, that twenty minutes before the great shock a trifling one was felt, a circumstance which I did not hear of in any other part. He was at the time on the island of Caucahue, (one of the many islets on the inland shore of Chiloe) and at the time wrote down the following remarks in his pocket-book: “Felt an earthquake at half-past eleven o’clock, motion horizontal and slow, similar to that of a ship at sea going before a high regular swell, with three to five shocks in a minute, somewhat stronger than the continued motion; direction from N.E. to S.W. Forest trees nearly touched the ground in these directions, but none fell in our vicinity;—pocket compass placed level on the ground, N. point set to lubbers’ point; remarked that it vibrated during the violent |603| shocks two points to westward and only half a point to eastward; stood at N. when the motion was less violent. Four minutes afterwards, a shock more violent than any of the preceding ones, affecting the compass as before: another violent shock, and then the movements became gradually less distinct, and eight minutes after the first commencement, they entirely ceased.” I have quoted Mr. Douglas’s statement with regard to the compass, although it is not clear how any movement could have forced it to oscillate towards one side more than to another. I presume, however, if the needle with its card had not been acted on by the magnetic force, it would have been thrown in the trough (if such an expression may be used,) of the undulation, that is, in a N.W. and S.E. line, and, therefore, that the recurrence of this tendency, acting against the polar attraction, caused the unequal oscillations, as described. In my Journal of Researches,† I have endeavoured to show, that the vorticose movement, which in several earthquakes appears to have affected the stones in buildings, possibly may be explained on the same principle, namely, that the stones are so shaken that they arrange themselves according to their forms, in the line of vibration, as the compass would have done, had it not been acted on by the magnetic force. That the movement of the surface was

* †

Compendio de la Historia del Reyno de Chile, vol. i. p. 33. [Juan Ignacio Molina (1740–1829), Chilean Jesuit priest and naturalist. Molina 1794.] Journal of Researches during the Voyage of the Beagle, p. 376.

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undulatory, is shown by the fact, that at Concepcion the walls which had their extremities directed towards the chief point of disturbance generally remained erect, although much fractured; whilst those extending at right angles to these first lines, were hurled to the ground; for in the latter case we must suppose, that the whole wall was thrown at the same moment out of its perpendicular by coinciding with an undulation. The fact mentioned by Mr. Douglas of the trees almost touching the ground from the effects of the movement, though very extraordinary, has been noticed by eye-witnesses of earthquakes in other parts of the world.* The circumstance (even supposing it somewhat exaggerated) is the more remarkable, since at Valdivia, which is situated on the coast between this island and the centre of the disturbance at Concepcion, the shock produced no such effects. I was seated in a thick wood there, during the earthquake, and the trees were only slightly shaken.4 The range of the Cordillera opposite Chiloe, a narrow island ninety miles in length, is not nearly so lofty as in Central Chile, and a few only of the culminant peaks, which are all active volcanos, exceed 7000 feet in height. Mr. Douglas has given me a detailed account of the effect produced on them by the shock. |604| The volcano of Osorno had been in a state of moderate activity for at least forty-eight hours previously; Minchinmadom in much the same gentle action as for the last thirty years; and the Corcovado had been quiet during the whole previous twelve months. “At the moment of the shock, Osorno threw up a thick column of dark blue smoke, and directly that passed, a large crater was seen forming on the S.S.E. side of the mountain; it boiled up lava, and threw up burning stones to some height, but the smoke soon hid the mountain. When seen again a few days afterwards, it showed very little smoke by day, but by night, the new crater, as well as the old one on its truncated summit, shone with a steady light. This volcano appears to have remained in activity throughout the year. The action of Minchinmadom was similar to that of Osorno: two curling pillars of white smoke had been observed all the morning; but during the shock, numerous small chimneys seemed to be smoking within the great crater, and lava was thrown out of a small one just above the lower verge of the snow. Eight days afterwards this little crater was extinct; but at night five small red flames were seen in a line, equidistant from each other, like those in the streets of a village. By the 1st of March its activity was much diminished; but on the 26th there was a smart earthquake, and at night the five fires were again seen. A fortnight afterwards the tops of fifteen conical hills could be seen within the wall of the great crater, and at night nine steady fires, of which seven were in a line, and two straggling.” At the time of the great shock, the Corcovado showed no signs of activity, nor was it heard in action after the Cordillera were hidden in the clouds. Mr. Douglas, however, states, that when that volcano was visible a week afterwards, the snow was seen to have been melted around the N.W. crater. On Yantales, a lofty mountain south of the Corcovado, three

*

This is mentioned by Dolomeu as a well-known fact during the Calabrian earthquake of 1783. [Dieudonné Sylvain Guy Tancrède (Déodat) de Gratet de Dolomieu (1750–1801), French mineralogist and geologist. Dolomieu 1783.] Lyell’s Principles of Geology (5th edition), vol. ii. p. 217. [Lyell 1837.]

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black patches having the appearance of craters were observed above the snow-line; and Mr. Douglas did not recollect having seen them before the earthquake. Bearing in mind, that on many occasions, the melting of the snow on a volcano has been the first indication of a fresh period of activity, and that, as I shall presently show, the eruptions of the Corcovado and Orsono are sometimes co-instantaneous, I think there can be little doubt that these appearances prove the effects of the great convulsion of the 20th of February to have been felt by these, the most southern volcanos in America. Mr. Douglas states, that on the night of November 11th (ten months after the overthrow of Concepcion), Osorno and Corcovado both burst out in violent action, throwing up stones to a great height, and making much noise. He subsequently heard, that on the same day, Talcahuano, the port of Concepcion, little less than 400 miles distant, was shaken by a severe earthquake. This latter statement has since been confirmed to me by a gentleman, who was at the time resident in Chile. Here, then, we have a repetition of the same connected action, which was displayed in so remarkable a manner on the 20th of February. Mr. Douglas in conclusion adds, that on December the 5th his “attention was arrested by the grandest volcanic spectacle he had ever beheld; the S.S.E. side of Osorno had fallen in, thus uniting the two craters, which appeared like one great river of fire. Enormous quantities of ashes and smoke were erupted during the succeeding fortnight.” It is therefore evident, that the volcanic chain from Osorno to Yantales (a length of nearly 150 miles) was affected not only at the moment of the great shock of February 20, 1835, but remained in very unusual activity during many subsequent months. Again, on November 7, 1837, two years and three quarters after the overthrow of Concepcion, both Valdivia and San Carlos, the capital of Chiloe, were violently convulsed, even more so, according to M. Gay,* than in 1835, or on any former recorded period; this shock was sufficiently |605| strong (bastante recio)† at Talcahuano; and it appears from the evidence of Captain Coste,5 published in the Comptes Rendus,‡ that the island of Lemus in the Chonos Archipelago, 200 miles south of San Carlos, was, by this same earthquake, upraised more than eight feet: describing the present state of the island, M. Coste says, “des roches jadis toujours couvertes par la mer, restant aujourd’hui constamment découvertes.” We see, therefore, that, in 1835,—the earthquake of Chiloe,—the activity of the train of neighbouring volcanos,—the elevation of the land around Concepcion,—and the submarine eruption at Juan Fernandez, took place simultaneously, and were parts of one and the same great phenomenon. Again in 1837 a large part of the same area was violently affected, whilst a district, 200 miles southward of San Carlos in Chiloe, instead, as in 1835, of 300 northward of it, was permanently upraised. We must therefore believe, that these two elevations of the land, although not simultaneous, were effects of the same motive power intimately connected together. Although the earthquake of February 1835 was so severe in Chiloe, yet at Calbuco, a village situated on the mainland opposite the northern extremity of the island, it was felt with * ‡

† Comptes Rendus, 1838. Séance Juin 11. [Gay 1838.] Voyages of the Adventure and Beagle, vol. ii. p. 418. Comptes Rendus, October, 1838, p. 706. [Vincendon-Dumoulin 1838.]

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much diminished violence, and on the neighbouring Cordillera (near Mellipulli) not at all. Some men who had been employed in the mountains splitting fir-planks, when they returned in the evening to Calbuco and were told of the shock, said, that “about the time mentioned, they recollected that they had not been able to strike fair with the axe, and that they had spoilt a board or two, by cutting too deep.” This probably is not so fanciful as it at first appears; at least it shows that, if there were any motion, it was of an exceedingly gentile kind. It is a most interesting circumstance thus to find, that the great columns of smoke shot forth from the tall chimneys of the Andes, relieved the trembling ground, which at that moment was convulsed over the whole surrounding country. Mr. Caldcleugh,* has stated in his Memoir, that several volcanos in the Cordillera northward of Concepcion were in a state of great activity after the earthquake. It is therefore remarkable that Villarica (near Valdivia), a volcano which is more frequently in eruption than almost any other in the range, although situated in an intermediate position, between those of central Chile and those in front of Chiloe, was not in the least affected. The day was very clear, and although not at the moment of the shock, yet within two hours after it, I attentively watched its truncated summit, but did not perceive the least signs of action. This circumstance probably has an intimate relation with the less force of the earthquake in the same intermediate district. In 1837, however, it suffered similarly with Chiloe. Although Villarica was passed over in 1835, yet in the account of the earthquake of 1822 at Valparaiso, it is said, “at the moment the shock was felt, two volcanos in the neighbourhood of Valdivia (where the earthquake was pretty sharp) burst out suddenly with great noise, illuminated the heavens and the surrounding country for a few seconds, and as suddenly |606| subsided into their quiescent state.”† The vents in Central Chile, nearer the chief focus of disturbance, were not at the time of that earthquake affected; but according to the information received by Dr. Gillies‡ in 1836,6 from a miner who had resided many years in sight of the volcano of Maypu, its eruptions were very frequent during the four years immediately subsequent to it. Many other instances are on record of earthquakes having passed over certain districts, in the same manner as we see the eruptive force acted with respect to Villarica. Humboldt§ remarks, that the inhabitants of the Andes, speaking of an intermediary ground, which is not affected by the general motion, say with simplicity, “that it forms a bridge” (que hace puente); and he adds, “as if they meant to indicate by this expression, that the undulations were propagated at an immense depth under an inert rock.”**

* † ‡ § **

Phil. Transact. for 1836. [Caldcleugh 1836.] I likewise was informed by an intelligent person, that he had seen, from the plain near Talca, a volcano in the Cordillera in great activity on the night subsequent to the earthquake. Journal of Science, Vol. xvii. [Anon. 1823.] The Edinburgh Journal of Natural and Geographical Science, August 1830, p. 317. [John Gillies (1792–1834), naval surgeon and naturalist. Gillies 1830.] Humboldt’s Personal Narrative, Vol. iv. p. 21. English Translation. [Humboldt and Bonpland 1814–29.] Another instance of earthquakes, violently affecting distant regions and passing over the intermediate country, is mentioned in the “True relation of the Earthquake of Lima, 1746.” [Lozano 1748.] It is there said (p. 192) that the shock was most violent at Lima and Callao, becoming gradually less along the coast, but that at Guancavelica excessive shocks were felt and noises heard. The editor believes, there is no other place called Guancavelica except the famous quicksilver mines of that name, situated 155 miles to the S.E. of Lima. MacClelland (Report on the Coal Mines of India, p. 43,) mentions some cases of intermediate places being little shaken during great earthquakes. [McClelland 1838.]

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On the identity of the force which elevates Continents with that which causes volcanic outbursts It has frequently happened, that during the same convulsion large areas of the globe have been agitated, and strange noises propagated to countries many hundred miles apart;* but in these cases, it is not possible to form any conjecture over how wide an extent, any actual change has taken place in the subterranean regions. It is different, when we hear from Humboldt, that at the moment when the volcano of Pasto ceased to eject a column of smoke, the city of Riobamba, sixty leagues to the southward, was overwhelmed by an earthquake; for the effect here produced certainly cannot be explained by the mere transmission of a vibration.† During the Concepcion earthquake, |607| at one extremity of the area affected, the snow was melted on Yantales and the neighbouring vents renewed their activity; whilst at Juan Fernandez, at the distance of no less than 720 geographical miles from Yantales, an eruption took place beneath the sea; and soon afterwards the volcanos in the Cordillera, 400 miles to the eastward of that island, burst forth in action,—a large extent also of country, intermediate between these extreme points, being permanently upraised. To form a just idea of the scale of this phenomenon, we must suppose, during the same hour, Europe to be shaken from the North Sea to the Mediterranean,—a large tract of the eastern coast of England to be permanently elevated,—a train of volcanos on the northern coast of Holland to burst forth in action,—an eruption to take place at the bottom of the sea, near the northern extremity of Ireland,—and the ancient vents of Auvergne, Cantal, Mont d’Or, and others, so long extinct, each to send up to the sky a dark column of smoke. Moreover, as, in Chile, a large part of the same area was two years afterwards most violently shaken, at the same time that Lemus was upraised, so must we imagine that, subsequently also, in Europe, whilst France, from the English Channel to the central provinces, where the volcanos had been excited into long and fierce action, was desolated by an earthquake, an island in the Mediterranean was permanently elevated;—then should we have the subterranean movements which shook South America on the 20th of February, 1835, and on the 7th of November, 1837, acted in countries with which we are familiar. When first considering these phenomena, which prove that an actual movement in the subterranean volcanic matter occurred almost at the same instant of time at very distant

*

†

As examples of the first case, may be adduced the trembling of the ground on the coast of Chile along a space of more than one thousand miles; and during the Lisbon earthquake in 1755, countries about 3000 miles apart were affected (see Michell on Earthquakes: Phil. Trans. 1760.). [Michell 1760.] With respect to the second case, Humboldt states, that during the eruption at St. Vincent’s, subterranean noises were heard on the banks of the Apure, a distance of two hundred and ten leagues. (Person. Narr. Vol. iv. p. 27.) During the eruption of Coseguina in 1835, it is said, that noises were heard at Jamaica, 660 miles distant. As other instances of the same kind, I may mention the outburst in 1822, of the volcanos near Valdivia at the same moment that Valparaiso, nearly 400 miles distant, was levelled to the ground. Again, in 1746, when Lima was overthrown, three volcanos near Patas and one near Lucanas, the two places being 480 miles apart from each other, burst forth during the same night. (Ulloa’s Voyage, Vol. ii. p. 84.) [Antonio de Ulloa (1716–95), Spanish naval captain and administrator in the Americas. Juan and Ulloa 1806.] I allude to these cases more particularly, because that distinguished philosopher, M. Boussingault (Bulletin de la Soc. Géolog. Vol. vi. p. 54.), having been much struck with the fact, that the earthquakes which have been most destructive to human life have been unaccompanied by volcanic outbursts, has, I think, generalized the remark too far. [Jean Baptiste Joseph Dieudonne Boussingault (1802–87), French agricultural chemist. Boussingault 1834–35, cited in Lyell 1835, 2: 96.] The earthquake of Concepcion in 1835 undoubtedly was one of extreme violence, although, from happening in the day, and from commencing gradually, it caused but few deaths (probably in the whole province not more than 70); nevertheless we have seen, that it was accompanied by co-instantaneous eruptions from several and very distant points.

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places, the idea of water splashing up through holes in the ice of a frozen pool, when a person stamps on the surface, came irresistibly before my mind. The inference from it was obvious, namely, that the land in Chile floated on a lake of molten stone, of which the area, as known from the various points in eruption on the day of the earthquake, would be nearly double that of the Black Sea. If this inference be denied, the only alternative is, that channels from the various points of eruption unite in some deep-seated focus, like the arteries of the body in the heart, whence |608| an impulse can be transmitted to distant parts of the surface, with nearly equal force. But according to this view, if two separate trains of volcanos in the Andes have any connexion whatever, which seems highly probable from the symmetry of the Cordillera, (and possibly an intimate one, as will presently be discussed,) then the common focus, from which the two main branches are sent off, must be seated at an enormous depth. But all the calculations regarding the depth at which molten rocks must necessarily be met with, if they can be at all trusted,* tend to prove, that the earth’s crust is not much more, and perhaps less, than twenty miles in thickness; and if this be so, the crust may, indeed, be well compared with a thin sheet of ice over a frozen pool. These considerations are, perhaps, of little weight, but we must bear in mind, that the elevation of many hundred square miles of territory near Concepcion is part of the same phenomenon, with that splashing up, if I may so call it, of volcanic matter through the orifices in the Cordillera at the moment of the shock; and as this elevation is only one of a long series, by which the whole coast of Chile and Peru, even for more than a thousand miles, has been upraised several hundred feet within the recent period, (as I endeavoured to show in a paper formerly read to the Society,† and I hope hereafter to prove more fully,) the body of matter added below must have been enormous. When we reflect on this, it is obvious, that the term channel cannot be applied to a means of communication extending beneath a large portion of a continent, and from the interior of the globe to the superficial crust.‡ The facts appear to me clearly to indicate some slow, but in its effects great, change in the form of the surface of the fluid on which the land rests. |609| In a geological point of view, it is of the highest importance thus to find three great phenomena,—a submarine outburst, a period of renewed activity through many habitual vents, and a permanent elevation of the land,—forming parts of one action, and being the effects of one great cause, modified only by local circumstances. When we consider, that the southern volcanos were in eruption some days before the earthquake, and that one of them, *

† ‡

M. Parrot, however, (Mémoires de l’Acad. Imp. des Sciences de St. Pétersbourg, Tom. i. 1831. Science. Math. Phys. et Naturelles) altogether denies that the data are sufficient to form any judgment on this subject. [Georg Friedrich von Parrot (1767–1852), Estonian physicist. Parrot 1831.] Proceedings Geol. Soc., Vol. ii. p. 446, Jan. 1837. [Darwin 1837, F1645 (p. 32).] Professor Bischoff (Edinburgh New Philosophical Journal, Vol. xxvi. p. 59, 1838.) has even argued that “the immense masses of lava ejected from a single volcano, and the enormous extent in which volcanic actions are felt at the same time, scarcely leave room to doubt that every active volcano is in immediate communication with the whole melted matter in the interior.” [Karl Gustav Bischof (1792–1870), German chemist and professor of geology at the University of Bonn. Bischof 1839.] How incomparably stronger this argument is, if applied to the plutonic as well as volcanic rocks, composing the great masses of the Cordillera! but now that we know, that continental elevations are caused by the very same impulses with those which eject lava and scoriæ through the mouths of volcanos, the argument from the bulk of matter observable in ejected or interjected masses of rock, may be passed over, since the matter added below, when a whole kingdom is permanently elevated, must far exceed that composing either a volcanic hill or the axis of a mountain-chain; and therefore we are so much the more strongly urged to look for its source in “the whole melted matter of the interior,” and not in any local receptacle.

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Minchinmadom, has seldom been dormant for the last thirty years, and that they all remained active for many months afterwards, we must conclude that the impulse given to them at that moment, was of the same nature with the force which has kept up their activity during the many ages necessary to accumulate the volcanic matter into great snow-clad cones, and which force still continues to add to their height. If the earthquake or trembling of the ground (which, however, we have seen was less near these volcanos than elsewhere) had acted in no other way, than in merely breaking the crust over the lava within the craters, a few jets of smoke might have been emitted, but it could not have given rise to a prolonged and vigorous period of activity. But the power which manifested itself in this renewed action, and to which same power, acting at former periods, the entire formation of these several volcanos has evidently been due, was likewise the cause of the permanent elevation of the land;—a power, I may remark, which acts in paroxysmal upheavals like that of Concepcion, and in great volcanic eruptions, in precisely the same manner, for both these phenomena occur only after long intervals of rest, during which the volcano merely casts out, perhaps, a few showers of scoriæ, and the land rises with so slow a movement that it is called insensible;—therefore no theory of the cause of volcanos which is not applicable to continental elevations can be considered as well-grounded. Those who believe that volcanos are caused by the percolation of water to the metallic bases of the earth, or simply to intensely heated rock, must be prepared either to give up this view, or to extend it* to the elevation of such vast continents as that of South America. |610| On periods of increased Volcanic Action affecting large Areas Humboldt, when describing certain volcanic phenomena in that part of South America which borders the West-Indian sea, seems to consider, that periods of increased activity affect large portions of the surface of the earth. He has drawn up the two following tables,† to which I have added a third, containing the remarkable events that happened during the years 1834 and 1835: 1st. Table of Volcanic Phenomena. 1796. November. 1797. February 4th. — September 27th. — December 14th.

*

†

The volcano of Pasto began to emit smoke. Destruction of Riobamba. Eruption in the West-Indian Islands. Volcano of Guadaloupe. Destruction of Cumana.

The arguments in favour of the theory, that steam, produced by the percolation of water to the interior of the cooling planet, is the motive power in volcanic action, has been lately strongly put by Prof. Bischoff in his paper in the Edinburgh Journal (Vol. xxvi. p. 25.). That it must be a modifying cause of great importance seems highly probable; but that it is the primary one of continental elevations, I cannot admit. The phenomenon, as it appears to me, is on far too grand a scale to harmonize with such an explanation. Can the rising of the whole west coast of South America, and of the whole width, at least of the southern portion of it, be explained by the lateral force exerted during the general shrinking of the earth’s crust, modified only by the formation of steam under high pressure, in those parts where water has percolated to the heated interior? Such an explanation surely is inadmissible. Personal Narrative, Vol. iv. p. 36. I have altered some of the dates in these tables, as they did not agree with the text or with the well-known period of the events.

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2nd Table. 1811. May.

Beginning of the earthquakes in the Island of St. Vincent, which lasted till May 12th. — December 16th. Beginning of the commotions in the Valley of the Mississippi and the Ohio, which lasted till 1813. — December. Earthquake of Caraccas. 1812. March 26th. Destruction of Caraccas, earthquakes, which continued till 1813. — April 30th. Eruption of the volcano in St. Vincent’s, and on the same day, subterranean noises at Caraccas and on the bank of the Apure.

3rd Table. 1834. January 20th. — May 22nd. — September 7th. 1835. January 20th. Before day-light in the morning.

— February 12th. — February 20th. 11½ A.M.

— November 11th. — December 5th.

Sabiondoy, lat. 1° 150 N. (near Pasto), dreadful earthquake; eighty persons perished; town of Santiago swallowed up. Santa Martha, lat. 11° 300 N.; two-thirds of the town thrown down; in course of a few days, sixty bad shocks. Jamaica,—violent earthquake, town not much damaged. Osorno, lat. 40° 310 S. in eruption. Aconcagua, lat. 32° 300 S. in eruption Coseguina, lat. 13° N. in terrific eruption, continuing in activity during the two ensuing months. Earthquake at sea, very strong off the coast of Guyana. Juan Fernandez, lat. 33° 300 S., submarine eruption. Concepcion, (lat. 36° 400 S.), and all the neighbouring towns destroyed by an earthquake; the coast permanently elevated. Volcanos along the whole length of the Cordillera of Chile in eruption. N.B. These volcanos remained in activity for some months subsequently, and many earthquakes were felt. Concepcion, severe earthquake; Osorno and Corcovado in violent action. Osorno fell in with a grand explosion. |611|

With respect to these tables, it must be observed, that we can never feel sure that the connexion of volcanic phenomena at very distant points is real, until some strongly marked event takes place during the same moment at those points, the intermediate country being likewise affected to a certain degree. In the first two tables, the connexion of the West-Indian vents and the coast of Venezuela may be admitted as almost certain,* nor is the distance very great, being at most only 400 miles. But when, on the one hand, we include Quito, distant from the above area more than 1200 miles, and, on the other, the Valley of the Mississippi, the case is very much more doubtful. The coincidence certainly is very remarkable, both in regard to the commencement and the cessation of

*

Humboldt’s Personal Narrative, vol. ii. p. 226., and vol. iv. p. 36.

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the long series of earthquakes which affected South Carolina, the basin of the Mississippi, the Leeward Islands, and Venezuela: yet New Madrid is more than 2000 miles from the latter. A repetition alone of such coincidences can determine how far the increased activity of the subterranean powers, at points so remote, is the effect of some general law, or of accident. We now come to the third table, with which we are more particularly concerned. I have already described in detail the remarkable volcanic phenomena which happened, in connexion with each other, on the morning of February 20th, 1835, and likewise during the subsequent year. On January 20th, one month previously, three eruptions, as stated in the table, occurred almost at the same hour in very distant points of the Cordillera. Near midnight on the 19th, the summit of Orsono shone like a great star in the horizon; and this appearance soon increased into a magnificent glare of light, in the midst of which, by the aid of a telescope, great dark bodies were seen to shoot upward and to fall down in endless succession. When I was at Valparaiso some time afterwards, Mr. Byerbache,7 a resident merchant, informed me, that sailing out of the harbour one night very late, he was awakened by the captain to see the volcano of Aconcagua in activity. As this is a most rare event I recorded the date. Some time afterwards papers arrived from Central America giving an account of one of the most fearful eruptions of modern times.* “On the 19th of January, after twenty-six years’ repose, a slight noise, attended with smoke, proceeded from the mountain of Coseguina. On the following morning (the 20th) about half-past six o’clock, a cloud of very unusual size and shape was observed by the inhabitants to rise in the direction of this volcano.” Enormous quantities of ashes and pumice were then ejected, and the air was darkened, and the ground convulsed, during the three succeeding days. Nearly two months afterwards the volcano was in action. Mr. Caldcleugh observes, that perhaps the only parallel case on record is the well-known explosion of Sumbawa in 1815. When I compared the dates of these three events, I was astonished to find that they agreed within less than six hours of each other. Aconcagua is only 480 miles north of Osorno, but Coseguina is about 2700 north of |612| Aconcagua. It may be asked, were these three eruptions, which burst through the same chain of mountains, in any respect connected, or was the coincidence accidental? We cannot be too cautious in guarding against the assumption that phenomena are connected, because they happen at periods bearing some determined relation to each other. If we wished to show that the subterranean forces acted after periods of a century, as has sometimes been believed, we might adduce the case of Lima, violently shaken by an earthquake on the 17th of June, 1578, and again on the very same day in 1678; or the eruptions of Coseguina in the years 1709 and 1809, which are the only two on record previous to that of 1835. Again, we might urge, on such grounds, that the Guatimala

*

Caldcleugh on the volcanic eruption of Coseguina. Philosophical Transactions, 1836, p. 27.

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convulsions follow, at the interval of one year, those near Pasto; for a district in the neighbourhood of the latter place was overthrown by a violent shock precisely one year before the explosion of Coseguina; both having occurred on the 20th of January. Cosme Bueno8 imagined that this relation actually did exist between the subterranean movements in Guatimala and Peru, and this case makes one more to the list which I have subjoined* as extracted from Humboldt. With respect to the simultaneous eruptions of Aconcagua and Osorno, there is little difficulty in admitting that they may have been connected, because in this same region, and only a month subsequently, volcanos further apart were affected by the same impulse. There is nevertheless this remarkable difference in the two cases;— the last, or that of February the 20th, was a period of commotion throughout the kingdom of Chile, while the simultaneous eruption of Aconcagua and Osorno appears to have been unaccompanied by any general movement in the subterranean regions. This eruption, probably, was the first indication of those great volcanic disturbances which ensued exactly one month afterwards; for it seems to be a very general occurrence in earthquakes, that weak spasms precede the worst convulsions. Thus, in 1822, on the 4th of November, Copiapó (lat. 27° 100 ) was visited by a severe shock, which damaged many houses; and was followed the next day by a much more violent earthquake, which nearly destroyed the town, and did considerable |613| injury to that of Coquimbo, in lat. 29° 500 .† On the 19th of the same month Valparaiso was almost destroyed. Other instances‡ might be brought forward to show that most earthquakes, though appearing sudden, are in truth parts of a prolonged action, as evinced both by the events which precede and those which follow it. Although, possibly, we may allow that the eruptions of Aconcagua and Osorno, occurring in the middle of the same night, were connected together, and formed a part of the great subsequent disturbances,—yet what must we conclude respecting their coincidence with Coseguina, so immensely remote? The case is rendered far more extraordinary by two of the three volcanos being generally quiescent. Coseguina, according to Mr. Caldcleugh, burst

*

† ‡

Mexico.

Peru.

Difference of time.

(Lat. 13° 320 North. 30th of November, 1577. 4th of March, 1679. 12th of February, 1689. 27th of September, 1717.

(Lat. 12° 20 South.) 17th of June, 1578. 17th of June, 1678. 10th of October, 1688. 8th of February, 1716.

Six and a half months subsequent. Eight months in advance. Four months in advance. Seven and a half months in advance.

Humboldt’s Personal Narrative, Vol. ii. p. 227. These facts perhaps tend to show that periods of increased volcanic energy are common to remote parts of the continent; but as the order of priority is not constant, I cannot believe any other law is indicated. Journal of Science, Vol. xvii. Several distinct cases are known in which springs and wells have been affected, their water rendered turbid, and altered in quantity, previously to bad earthquakes. This was observed at Lisbon in 1755; and in New England during two or three days before a shock, “the waters of some wells were rendered muddy and stank intolerably.” (Michell, Philosophical Transactions, 1760, p. 44.) Humboldt and others have noticed, that the wells in the neighbourhood of Vesuvius are affected previously to its bad eruptions. These facts appear explicable, on the idea of a slight stretching or movement taking place in the crust, before its tension is overcome, a fissure formed, and, as a consequence, an earthquake or eruption caused. Courrejolles, also, has remarked in his memoir on earthquakes (Journal de Phys., Tom. lxiv. p. 106.), that great earthquakes are almost always preceded by lesser ones. [Courrejolles 1802.]

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forth after twenty-six years of repose; and Aconcagua so seldom manifests any signs of activity, that it had even been doubted whether any part of this gigantic mass, with an altitude of more than 23,000 feet, is of volcanic origin. To illustrate the case: if we suppose Stromboli and Vesuvius to be in violent eruption on the same hour of the night, little would be thought of the coincidence; but it would be otherwise if this should happen with Vesuvius and Etna; and our surprise would be greatly increased if we afterwards heard that Hekla, after twenty-six years’ repose, had burst forth at the same time with tremendous explosions. Nevertheless, if such a coincidence had occurred in Europe, a country possessing no unity of character, and the two points not being more than 2000 miles apart, it is very doubtful how far the phenomenon would have been worthy of consideration. But the case is different in America, where the volcanic orifices all fall on one great wall or fissure, (for the Andes may be indifferently so called,) and where the immensity of the level area on the eastern side, proves with what wonderful equability the subterranean forces have acted on this portion of the globe. Moreover, when a line of coast more than two thousand geographical miles in length has been elevated (as I hope hereafter to prove) within a period so recent, that, as compared to the countless past ages of which we possess records in the works of nature, it may be |614| reckoned as unity; on such a coast it ceases to be improbable, in any excessive degree, that the many impulses which together have produced the one grand effect, should sometimes have been absolutely simultaneous. It has long been remarked, that the vents throughout the Cordillera may be grouped into several systems. Thus we have already shown, that the extreme southern volcanos are connected with those of Central Chile; and I was informed by an intelligent resident that he had seen Aconcagua and two volcanos northward of it, in great activity together:—we thus have a portion of the Andes 780 geographical miles in length (about the distance from the south of England to Vesuvius) forming one connected system. Ulloa* states, that when Lima was overthrown in 1746, three volcanos near Patas and one near Lucanas burst forth; these places being 480 miles apart from each other. Moreover, Arequipa, to the south, has twice (1582 and 1687) been affected by severe earthquakes simultaneously with Lima. The distance between Arequipa (where there is an active volcano) and Patas is rather more than 600 miles; and this perhaps may form a second system. Humboldt† says, “It appears probable that the higher part of the kingdom of Quito, and the neighbouring Cordillera, far from being a group of distinct volcanos, constitute a single swollen mass, an enormous volcanic wall stretching from north to south, and the crest of which exhibits a surface of more than six hundred square leagues. Cotapaxi, Tunguragua, Antisana, and Pichincha, are placed in this same vault, on this raised ground.” He afterwards shows, from the phenomenon already alluded to, of the cessation of the column of smoke at the moment when Riobamba was overthrown, the connexion of these volcanos with those of Pasto and Popayan. This joint system is rather less than 300 miles in length. Again, to the

*

Ulloa’s Voyage, English Translation, Vol. ii, p. 84.

†

Personal Narrative, Vol. iv. p. 29.

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north at Guatimala, Mexico, and California, we have three groups of volcanos, each system being a few hundred miles apart. The connexion between the vents in each separate system has been, in some places, plainly shown, and is extremely probable in all; but what relation the different systems bear to each other is more doubtful. I am not aware of any fact on record, similar to the contemporaneous eruption of Osorno and Aconcagua with Coseguina. It must not, however, be overlooked, that such events may have happened every year since the Spanish conquest, without the coincidence having once been detected. Excepting from the occurrence of two accidents, I should never have known of this case. On that same night every vent in the Cordillera might have shown transient signs of activity, and six months afterwards it would have been as impossible to have discovered |615| that such had happened, as to have ascertained whether the next day were bright or clouded. There are some active and some nearly extinct craters, in the interval between the Chilian and Peruvian systems, (which is the longest of any, being 900 miles,) but they are situated in countries very thinly peopled, and in some parts entirely desert; and who is there in such cases to record phenomena, which, even if beheld, are thought of little consequence? Returning to the third table, I feel no doubt that the volcanic phenomena which occurred in S. America sometime previously as well as subsequently to the months of January and February 1835, were far more numerous than the average proportion during an equal length of time. This remark applies to the two tables copied from Humboldt. In looking at the dates of these events, it must be remembered that each date represents only the moment when the crust of the earth has given way beneath the force, which in some cases has already shown its action, and invariably continues to do so during a period, often of considerable length. Under this point of view, the earthquakes of Caraccas and New Madrid, of Coseguina and Concepcion, may be considered as actually contemporaneous. From these various circumstances, I am strongly inclined to believe, that the subterranean forces manifest their action beneath a large portion of the South American continent, in the same intermittent manner as, in accordance with all observation, they do beneath isolated volcanos,—that is, remaining for a period dormant, and then bursting forth throughout considerable districts with renewed vigour. Nature of the Earthquakes on the Coasts of South America I will now more particularly consider the nature of the earthquakes which occur at irregular intervals on the coast of South America. It cannot be otherwise than difficult to trace their precise origin, but the following considerations, as it appears to me, lead to one conclusion alone—namely, that they are caused by the interjection of liquefied rock between masses of strata. Ulloa, in his travels,* says, “Experience has sufficiently shown, especially in this country (South America), by the many volcanos in the Cordillera which pass through it, that the bursting of a new burning mountain causes a violent earthquake, so as totally to destroy all the towns within its reach, as happened at the opening of the volcano in the desert of Carguagoazo. This tremulous motion, which we may properly call an earthquake, does not *

Ulloa’s Voyage, Vol. ii. p. 85.

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so usually happen in case of a second eruption, when an aperture has been before made, or, at least, the motion it causes in the earth is comparatively but small.”* |616| Although the bursting forth of a new vent may invariably be accompanied by an earthquake, the converse is not true; for if it were, at Valparaiso, Concepcion, Lima, Caraccas, and other places, in the immediate neighbourhood of the part most violently shaken, an eruption must always have taken place, which, even if we suppose it to have occurred beneath the sea, is improbable in the highest degree. But we may suppose that these earthquakes are owing to some phenomenon analogous to volcanic eruptions. This opinion is much strengthened by the fact, that great earthquakes, like great eruptions, generally recur only after long intervals of repose, and they thus lead us to believe, that the subterranean force is relieved by either in the same manner. This, indeed, is the direct opinion of the inhabitants of the whole west coast of South America, who are firmly convinced of an intimate relation between the suppressed activity of the volcanos in the Andes and the tremblings of the ground. We have, also, seen that, when the island of Chiloe was strongly shaken, some men at work on the flanks of the Cordillera, between the volcanos of Osorno and Minchinmadom, (which both sent up dark columns of smoke, like signals to mark the new period of violence,) were quite unaware of the great convulsion, which then caused the shores of the Pacific to vibrate throughout a space of more than a thousand miles. There is, however, one difference, although more apparent than real, between earthquakes like that of Concepcion, and those alluded to by Ulloa. In the former, it has almost invariably happened, at least in those on the South American coast, that a vast number of shocks have followed the first great convulsion,† and these, as well as the accompanying subterranean noises, have proceeded from the same quarter with the first shock, are therefore undoubtedly due to the very same cause, only acting with somewhat less intensity. Thus, even in the first twenty-four hours after the earthquake of |617| 1746 at Lima, no less than 200 horrible (I use the language of its historian) shocks were counted. Now in the other case, Ulloa says, that when the orifice of eruption is once formed, the earth becomes nearly tranquil; yet we well know, that the volcano itself almost invariably continues in great activity for many weeks afterwards. Had Ulloa, however, stood near the crater itself, he would undoubtedly have felt those small tremors, which accompany each fresh explosion, as described by others who have been so circumstanced. The tremors, therefore, seem analogous to the secondary shocks; and, this being so, the phenomena in the two cases are in every respect closely similar. In a primary volcanic outburst, we know the cause to be the explosion of liquid and *

†

Michell, in his remarkable paper on Earthquakes in the Philosophical Transactions for 1760, (p. 580,) has quoted this same passage in confirmation of his view, that “the eruptions of volcanos which happen at the same time with earthquakes may, with more probability, be ascribed to those earthquakes, than the earthquakes to the eruptions, whenever at least the earthquakes are of considerable extent.” The term earthquake is here used to express the cause of the trembling of the ground. Sir James Hall, in his celebrated memoir on “Heat modified by compression,” (Edin. Phil. Trans., Vol. vi. p. 166,) [Hall 1815.] distinctly states “that the earthquakes which desolate countries not externally volcanic, indicate the protrusion from below of matter in liquid fusion, penetrating the mass of rocks;” but he does not extend this view, which is the same which I hold, to any comprehensive generalization, or restrict it to any particular class of earthquakes. Courrejolles, in his Memoir on Earthquakes, (Journal de Physique, Tom. liv. p. 106,) says, “Les grands tremblemens de terre sont presque toujours précédés et suivis quelque temps avant et après par de petites secousses.” Michell (Philosophical Transactions, 1760, p. 10) has given some instances of successive minor shocks, which appeared to travel from the same point, whence the previous more violent ones had come.

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aeriform matter, first through solid strata, and afterwards through a nearly open passage; hence we are led to conclude, that the cause of the simple earthquake, with its secondary shocks, are explosions of a similar nature, which, however, do not open a passage, but rend successively portions of the superincumbent masses. At Concepcion, where the streets run in two series, at right angles to each other, the walls were affected, as already observed, according to their direction. This was strikingly exemplified in the cathedral, where the great buttresses, built of solid brickwork, were cut off as if by a chisel, and hurled to the ground; whilst the wall, to support which they had been vainly built, though much shattered, stood erect,—for the latter had its extremity directed towards the point whence the vibration travelled, but the buttresses were in lines parallel to the undulation. Nearly similar circumstances were observed* in 1822 at Valparaiso. At the great earthquake of Caraccas the direction of the vibration was E.N.E. and W.S.W., and some definite direction appears to have been observed in almost every violent earthquake. Now, it may be asked, could a vibration, which had travelled upwards through the earth from a profound depth, be felt on the surface, as if it had come from a given point of the compass, and could it likewise determine the overthrow of walls according to their direction with respect to any such point? It appears to me clearly not; but that a vibration to produce such effects must be transmitted from the rending of strata, at a point not very deep below the surface of the earth. Earthquakes generally affect elongated areas. In the shock of 1837, in Syria, the vibration was felt “on a line 500 miles in length by 90 in breadth.”† Humboldt‡ remarks, that earthquakes follow the coast of New Andalusia in the |618| same manner as they do that of Peru and Chile. Thus, at Valparaiso in 1822, the movement was felt along 800 miles of the shore of the Pacific; and at Concepcion, in 1835, for the greater length of more than 1000 miles; but on no occasion has the shock been transmitted across the Cordillera to a nearly equal distance. In 1835 the rocking of the ground was so gentle at Mendoza, that an old man, one of the inhabitants, (and every one in these countries is possessed with an almost instinctive power of perceiving the slightest tremor,) told me, that for some time he mistook the movement of the ground for a giddiness in his head, and that he called out to his friends that he was going to die. At Concepcion, Valparaiso, Lima, and Acapulco,§ the residents believe that the disturbance generally proceeds from the bottom of the neighbouring sea; and thus they explain the unquestionable fact,** that the inland towns are generally much less injured than those near the coast. It does not appear, that the disturbance proceeds from any one point, but from many ranged in a band; otherwise the fact of the linear and unequal extension of earthquakes would be unintelligible. Thus, in 1835, the island of Chiloe, the neighbourhood of Concepcion, and Juan Fernandez, were all violently affected at the same * † ‡ §

**

See Miers’s Travels in Chile, Vol. i. p. 392. [Miers 1826.] Proceedings of Geological Society, p. 540. April 5th, 1837. [Moore 1837.] Personal Narrative, Vol. ii., p. 224. At Acapulco, Humboldt says, the shocks came from three different quarters, the west, north-west, and south. (Polit. Essay on the Kingdom of New Spain; English Translation, Vol. iv. p. 58.) [Humboldt 1811.] Almost every author, from the time of Molina, makes this observation. See Molina’s Compendio de la Hist. del Reyno de Chile, Vol. i. p. 32. [Molina 1794–5.]

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time, and more so than the intermediate districts. In mountainous countries, such as New Andalusia, Peru, and Chile, when earthquakes follow coast lines, they may be said to extend parallel to the littoral chain of mountains. The last consideration I shall enter on, as indicating the cause of earthquakes, is, that in South America they have sometimes (if not, as I believe, generally)* been accompanied by elevations of the land; but this, judging from the Lima shock of 1746, does not appear to be a necessary concomitant, at least to a perceptible amount. It might at first be thought that, at Concepcion, the uplifting of the ground, which accompanied the first and great shock, would by itself have accounted for the whole phenomenon of the earthquake. The great shock, however, during the few succeeding days, was followed by some hundred minor ones (though of no inconsiderable violence), which seemed to come from the same quarter from which the first had proceeded; |619| whilst, on the other hand, the level of the ground certainly was not raised by them; but on the contrary, after an interval of some weeks, it stood rather lower than it did immediately after the great convulsion,—a consequence, perhaps, of the settling down of the shaken ground. In the same manner, in 1822, at Valparaiso, the permanent change of level in the rocks on the coast was observed the morning next after the great shock; though the earth continued to tremble at intervals for many days. In these instances of change of level we have, then, a clear indication of some cause of disturbance, superadded to that which produced the vibrations, and which, it is highly probable, would accompany the simple elevation of the coast in mass. From these considerations, we may, I think, fairly conclude, with regard to the earthquakes on the west coast of South America, 1st. That the primary shock is caused by a violent rending of the strata, which seems generally to occur at the bottom of the neighbouring sea. 2nd. That this is followed by many minor fractures, which, though extending upwards nearly to the surface, do not (excepting in the comparatively rare case of a submarine eruption) actually reach it. 3rd. That the area thus fissured extends parallel, or approximately so, to the neighbouring coast mountains. 4th. That when the earthquake is accompanied by an elevation of the land in mass, there is some additional cause of disturbance. And lastly, That an earthquake, or rather the action indicated by it, relieves the subterranean force, in the same manner as an eruption through an ordinary volcano. Now, what constitutes the axis, where visible, of most great mountain-chains? Is it not a wedge-formed linear mass of rock, which scarcely any geologist disputes was once fluid, and has since cooled under pressure? Must not the interjection of such matter between masses of strata have relieved the subterranean pressure in the same manner, as an ejection of lava and scoriæ through a volcanic orifice? The dislocation having been effected in that *

My belief is grounded on the fact that, on the same coasts, and within the same period, in which a vast number of earthquakes are recorded, there exist proofs of an elevation of the land; although the rise is not known to have been connected with any particular earthquake.

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portion of the upper crust of the earth, now forming a mountain, must not superficial vibrations, proceeding from a focus not deeply seated, have been propagated over the surrounding country? And, whatever direction these dislocations took, would not an area, elongated in the same line, have been affected by the vibration? In drawing this parallel, I state my belief, that those earthquakes, with their secondary shocks, which are attended by such phenomena as accompanied the earthquake of Concepcion in 1835, are caused by the rending of great masses of strata, and their interjection by fluid rock;—a process which must have formed one step in a line of elevation. |620| The inhabitants of Concepcion believed, that the vibrations proceeded from the southwest, in which quarter subterranean noises were likewise frequently heard. It is, therefore, a most interesting circumstance, that the island of Santa Maria, situated 35 miles distant in this direction, was found by Captain Fitz-Roy to have been elevated to nearly three times the height that the coast near Concepcion was upraised. At Tubul, S. by E. of Santa Maria, the land was raised 6 feet; at the southern extremity of the latter island, 8 feet; in its middle, 9 feet; and at its northern extremity, upwards of 10 feet.* These measurements, which were made with extreme care by Captain Fitz-Roy, seem to point out an axis of elevation in the sea off the northern end of Santa Maria. There is one remark, which I must introduce here. The motion of the earth, on February 20th, 1835, at Valdivia, appeared to me like that of a crust, spread over an undulating fluid; and in my Journal, I have compared the motion to the bending of thin ice, beneath a moving weight.9 Afterwards, when I became convinced that the crust there does rest upon a sea of molten rock, my first impression regarding the movement was strongly confirmed. Michell long since observed, (Phil. Trans., 1760, p. 8) that “the motion of the earth in earthquakes is partly tremulous and partly propagated by waves, which succeed one another, sometimes at larger and sometimes at smaller distances; and this latter motion is generally propagated much further than the former.” This distinction, I believe, is strictly true. Professor Phillips† argues that rocks, although elastic in their parts, are “very imperfectly so in their mass, owing to the numerous divisions which intersect them. Composed of such materials,” he says, the “crust of the earth does not, and in fact hardly can, vibrate, in the ordinary sense of this term; the motion observed is more similar to the undulation of a flexible lamina over an agitated liquid.” The result arrived at by this reasoning thus coincides with mine, drawn from the impression on my senses; and it, at first, appears to explain, in a very satisfactory manner, the propagation to greater distances of the long and gentle undulations than of the vibrations, by the transmission of the former in the subterranean fluid, and of the latter in the crust of the earth. With respect, however, to the supposed want of elasticity in the crust of the earth, taken in mass, I cannot agree with Professor Phillips. Michell, (Phil. Trans., 1760, p. 35,) when he adduces the fact of the great vibration, or rather oscillation, during gales of wind, of steeples, and even towers,‡ which may be said to be composed of a vast number of * † ‡

Geographical Journal, Vol. vi. p. 327. Lardner’s Encyclopædia, Geol., Vol. ii. p. 209. [John Phillips (1800–74), professor of geology at King’s College, London, 1834–40. Phillips 1837.] Lardner’s Encyclopædia, Geol., Vol. ii. p. 209.

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strata of different densities, and which are frequently traversed by fissures or faults, leaves |621| scarcely any doubt on the mind that a similar and much greater vibration might be transmitted from the depths of the earth, where the parts must be pressed together with incomparably greater force than in any building. Plausible as is the foregoing explanation of the two kinds of movements, I do not believe it to be the correct one; for if an undulation be ever produced in the subterranean fluid expanse, we can hardly conceive a more powerful cause of it, than the upward rush of a great body of molten rock and aëriform matter from the lowest abyss of a volcano: but we know that eruptions on an enormous scale have happened through old vents, even in areas subject to far-extended and undulating earthquakes, without such movements having been produced. From this consideration, and from the fact that the force of earthquakes appears to have a definite relation to the thickness of crust ruptured, as we may conclude from the great difference in the effects caused by an eruption through an old, and one through a new orifice, I do not conceive we are justified in admitting the hypothesis of an undulating fluid. The two kinds of movements may, possibly, be explained, by considering that when the crust yields to the tension, caused by its gradual elevation, there is a jar at the moment of rupture, and a greater movement may be produced by the tilting up of the edges of the strata and by the passage of the fluid rock between them. In breaking a long bar of steel, would not a jar be caused by the fracture, as well as a vibration of the two ends when separate? Mr. Hopkins,* in his Researches on Physical Geology, has demonstrated, that when an elongated area is elevated by a force acting equally beneath all parts, if the strata yield, fissures must be formed parallel to its longer axis, and other minor ones transverse to it. Knowing then with certainty, that the coast of Chile, near Concepcion, was elevated on the 20th of February, and likewise that the area affected by the earthquake was elongated;— bearing also in mind, that several of these elevations have occurred, as attested both historically and by the extensive beds of recent species of shells, at the altitude of some hundred feet, we are absolutely compelled to believe, that the area (without we assume that the strata possessed extraordinary powers of extension) was at that time fissured in lines, the principal of which were parallel to its longer axis. If, however, the elevatory force acted unequally in different parts, as was the case in Chile, we can understand, from the admirable generalization of the same author, that separate fissures might be formed, which would produce at the same instant, in distant places, separate shocks, perhaps of different intensities. Hence we need not suppose, that the shocks felt more strongly at Juan Fernandez, Concepcion, and Chiloe, than at intermediate points, proceeded |622| from any one focus, but that they were generated in each separate district,—the vibrations probably having, in each case, different directions.† This explanation is, I think, far more satisfactory than that

* †

Transactions of the Cambridge Philosophical Society, Vol. vi. Part I. At Concepcion the line of vibration appears to have been N.W. and S.E., coming from S.W. At Mocha, (an island between Concepcion and Valdivia), from the manner in which water oscillated in the bottom of a boat drawn up on shore, the vibration must have been N. and S. coming from either E. or W. For the facts alluded to, see Capt. FitzRoy’s account of the Voyages of the Adventure and Beagle, volume ii. p. 414.

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offered by Humboldt, of the supposed inertness of an intermediary mass of rock, in transmitting to the surface vibrations from a deeply-seated focus. On different kinds of Earthquakes; and conclusions regarding those which accompany Elevatory Movements I confine the foregoing observations to the earthquakes on the coast of South America, or to similar ones, which seem generally to have been accompanied by elevation of the land. But, as we know that subsidence has gone on in other quarters of the world, fissures must there have been formed, and therefore earthquakes. I think, it would be highly advantageous to geology, if the author who has followed out the effects of an elevatory force, would consider those produced by the failure of support in the arched surface of the globe. The earthquakes of Calabria, and perhaps of Syria, and of some other countries, have a very different character from those on the American coast. When Molina, the historian of Chile was in Italy, he was much struck with this difference; he says,* in Chile even the smaller shocks extend over the whole kingdom, and are propagated horizontally, whilst those which he felt at Bologna, were of small extension, but instantaneous, and commonly explosive. I will add, that in the accounts collected by Mr. Lyell† of the earthquakes of Calabria, Lisbon, and some other places, portions of the surface are described as having been absolutely engulphed, and seen no more: but this does not appear to have happened in any of the earthquakes on the west coast of South America. If the fluid matter, on which I suppose the crust to rest, should gradually sink instead of rising, there would be a tendency to leave hollows, and therefore a suction exerted downwards; or hollows would be actually left, into which the unsupported masses might be precipitated with the violence of an explosion. Such earthquakes, we may conclude, from what has been shown in the foregoing part of this paper, would seldom be accompanied by eruptions, and never, probably, by periods of renewed volcanic |623| energy. According to M. Boussingault,‡ those earthquakes in South America which have been most destructive to human life, that is, which have been most sudden and violent, have not coincided with volcanic eruptions. He adduces several instances, including the shocks felt at Caraccas in 1812; but, according to Humboldt,§ the connexion between the subterranean disturbances at that place and the West Indian vents can hardly be doubted. M. Boussingault’s remark, indeed, although perhaps generally true, should be taken with some reserve; for had the earthquake of Concepcion happened at night, thousands of persons must inevitably have perished. In a line of fracture, produced by subsidence, the distortion and overthrow of the strata would probably be even greater than in one of elevation, from the circumstance, that as soon as the weight of the mass overcame its cohesion, and it began to sink, there would be no counterbalancing power, like gravity during elevation, to check the movement, excepting, indeed, the lateral pressure of the masses together, and this would only add to the * ‡

† Compendio de la Historia del Reyno de Chile, Vol. i. p. 36. Principles of Geology, 5th edit. Vol. ii. Book ii. Chap. xiv. § Bulletin de la Soc. Geol., Vol. vi. p. 54. Personal Narrative, Vol. ii. p. 226, and Vol. iv. p. 6, English Translation.

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disturbance. There would be, in this case, no axis of injected plutonic rock, or at least not one protuberant above the general surface; and thus we may explain the extreme disturbance in the strata of countries which are only hilly, like parts of Great Britain; and the occurrence there of such axes of elevation, as they are generally called, but which probably, in most cases, would be more appropriately termed axes of subsidence. If the theory which I have given of the cause of the earthquakes on the west coast of South America be true, we might naturally expect on the same principle to find proofs of successive formation in the many parallel ridges, of which the Cordillera is composed. In the parts of Central Chile which I examined, this is true, even with regard to the two main lines; of which one is partly formed of inclined beds of conglomerate, consisting of pebbles derived from the rocks of the other. I have also evidence, but of a less satisfactory kind, that some of the exterior lines of mountains are altogether of subsequent date to the more central ridges. Moreover, in all parts of the Cordillera, there are proofs of an equable elevation in mass to a very great altitude. I was so much struck with this latter fact, connected with what I imagined must have taken place during the Concepcion earthquake, that I came to nearly the same conclusion, which Mr. Hopkins has demonstrated by his mathematical researches, namely, that mountain-chains are only subsidiary and attendant phenomena on continental elevations. If this be so, and few, after having read Mr. Hopkins’s memoir, will dispute it; then, as it is certain continental elevations have certainly taken place on a great scale within the |624| recent period, so, as certainly, must masses on the lines of fracture have been unequally lifted up and let down,—that is, some steps in the formation of a mountain-chain have been produced. I may here ask, when Mr. Hopkins* says, he “can in no way conceive the successive formation of parallel fissures, without hypotheses respecting the mode of action of the elevatory force, which are infinitely too arbitrary to be admitted for an instant,” has he considered the effects of long intervals of rest, during which the injected rock might become solid? Would not the crust in such case yield more readily on either flank, as I believe it must have done in the Cordillera, than on the line of an axis composed of solidified rocks, such as granite or porphyry? An extremely slow elevation of the land, with long intervals of rest, being the only kind of movement of which we have any knowledge, the slow cooling of that portion of the liquefied rock which is propelled into the upper parts of the crust, cannot be considered an arbitrary assumption. From the facts stated in this paper, we may safely conclude, that volcanic action, even on a very grand scale, as in the Andes, is only one effect of the power which elevates continents, at the slow rate at which the South American coast is now rising. In looking back to the past history of the world, we may learn from Mr. Lyell,† that there have been volcanic eruptions during every epoch, from that of the Cambrian formations to the present day. The ancient * †

Abstract of a Memoir on Physical Geology, by W. Hopkins, Esq., M.A., p. 31. [Hopkins 1836.] Elements of Geology. In the 24th chapter, Mr. Lyell has collected instances of volcanic eruptions in each of the great epochs of the geological history of Europe. The argument, which follows in the text, is the same with that advanced by this author in the Principles of Geology, (Book I. Chap. v.) but Mr. Lyell more particularly applies it to the earthquakes and convulsions, “caused by subterranean movements, which seem to be merely another portion of the volcanic phenomena.”

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eruptions seem to have been accompanied by all the circumstances which attend modern ones; nor is there any evidence, as remarked by the same author, that the quantity of matter ejected, in the greater number of ancient cases, was excessive. Therefore, we must conclude that continental elevations, one of the effects of the same motive power which keeps the volcano in action, has ordinarily gone on, since those ancient days, at the same slow rate as at present, and, consequently, as above inferred, the step-like formation of mountain-chains. It may, therefore, be questioned, whether we are justified in admitting the hypothesis of a paroxysmal elevation of any mountain-chain, without distinct proofs in each particular case, that a series of impulses, like those, which now acting frequently on the same lines, rend the earth’s crust, |625| and elevate unequally portions of it, could not have effected the observed effects. It is, however, a subordinate question, whether there exist proofs of paroxysmal violence in some mountain-chains; the important fact which appears to me proved, is, that there is a power now in action, and which has been in action with the same average intensity (volcanic eruptions being the index) since the remotest periods, not only sufficient to produce, but which almost inevitably must have produced, unequal elevation on the lines of fracture. Theoretical Considerations on the slow Elevation of Mountain-Chains The conclusion that mountain-chains are formed by a long succession of small movements, may, as it appears to me, be rendered also probable by simple theoretical reasoning. Mr. Hopkins has demonstrated, that the first effect of equably elevating a longitudinal portion of the crust of the earth, is to form fissures, parallel to the longer axis (with others transverse to them, which may here be neglected) of the kinds represented in the accompanying diagram (No. 1.), copied from that published in the Cambridge Philosophical Transactions.

But he further shows, that the square masses, now disjointed, will,—from the extreme improbability of the force uplifting them, when separate, equably, or from their settling down afterwards,—assume such position as that given in Diagram No. 2. In the Cordillera, which may be taken as a good example of the structure of a great mountain-chain, the strata in the central parts are inclined more commonly at an angle above 45°, than beneath it; and very often they are absolutely vertical.

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The axis of the lines of dislocation is formed of syenitic and porphyritic masses, which, from the |626| number of dikes branching from them, must have been fluid when propelled against the lower strata.* If then we suppose Diagram 2 to represent the section of the Cordillera before its final elevation, I may ask, how is it possible, that some of the masses of strata should be placed vertical, and others absolutely overturned, by the action of the fluid rock, without the very bowels of the earth gushing out? Should we not have one enormous deluge of volcanic matter, instead of wedge-formed, injected masses of solid crystalline rock? On the other hand, if we suppose the loftiest chain of mountains to be formed by a succession of shocks similar to those of Concepcion,—a few stronger and many slighter ones, separated from each other by long intervals of time,—then we may believe, that the formation of a fissure through the whole thickness of the crust would be the effect of many efforts on the same line, and that during the intervals, the rock first injected would become cooled. When, therefore, the tension (which, according to Mr. Hopkins, acts on the lower surface first)† caused the upper part to crack, the fissures, if on the same line, would meet the consolidated extremity of a dike, instead of the fluid mass below. In those cases, however, where the fissure happened to traverse at once the entire crust, a volcano would be formed, such as that near Juan Fernandez during the Concepcion earthquake. On the same principle, after the masses of strata had been very gradually lifted into the position represented in Diagram 2, the rock beneath the anticlinal axes, from having been propelled beyond its former subterranean isothermal line, would be cooled, and, if sufficient time were allowed, it would be consolidated. In this manner the strata, each new fracture being firmly cemented by the cooling of the injected rock, might be overturned into any possible position, and yet, from a gradually thickening crust being formed over the fluid mass, on which the whole is believed to rest, the earth would be protected from a deluge of lava. If this reasoning be sound, we may deduce this remarkable conclusion, that in a mountain-chain, having an axis of plutonic rock, which was propelled upwards in a fluid state, where the strata betray the

*

†

According to M. Boussingault (Bulletin de la Soc. Geol., Tom. vi. p. 55), this is not the case in the Cordillera of the Equatorial regions. He states that trachyte there forms the base of the mountains, and that it has been protruded in a consolidated form. But can the deep-seated axis of a gigantic mountain-chain be composed of trachyte,—a rock essentially volcanic? If we could penetrate to greater depths, it cannot be doubted we should find the trachyte graduating into some plutonic rock; and one may be allowed to suspect that its junction with the superincumbent strata would present very different appearances from that of the trachyte;—the trachyte, indeed, we may well imagine to be the crust of such plutonic rocks cooled under little pressure, and forced upwards on the surface of the molten mass, in a solid form. Cambridge Philosophical Transactions, Vol. vi. pp. 43–45.

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effects of |627| the most violent action, although it be on a gigantic scale, there we have the best evidence of an almost infinite series of small movements.* I will enter on only one other consideration connected with this subject. From having in my mind the proportional thickness of the strata, usually given in sections in geological works, I felt much surprise, when I crossed the Cordillera, and found highly-tilted anticlinal lines succeeding one another at short distances, that the rock composing the axis was not to be met with, except in patches in the valleys. If we suppose parts of the strata in Diagram 2 to be placed vertically, the rock of the axis would necessarily be exposed in wide spaces; but here, I believe, is the source of error,—geologists have not always sufficiently considered the thickness of the mass upturned, in relation to the distance of the parallel anticlinal lines one from another. In the Cordillera, in a width of about sixty miles, there are eight or more anticlinal lines; and thus the centres of the troughs and of the ridges are about four miles apart. Now, if we suppose the upturned crust to be only four miles thick, (which is somewhat more than can actually be seen,) the strata, when placed vertically, will occupy as great an horizontal extension as they did before they were disturbed. In Diagram 3, which I beg it may be understood is given merely to illustrate this one point, I have taken portions of strata of the same exact length as those in Diagram 2; but I have increased their thickness, so that it equals the distance of the anticlinal lines from each other;—we shall now see that not only the whole axis is covered, but that the masses cannot be forced into their former horizontal limits.

I have not, however, allowed for the immense abrasion which, under such circumstances, the lower |628| angles would suffer, nor for the denudation and rounding of the upper ones. This supposed crushing together of such gigantic fragments will, perhaps, explain the utter confusion, which must be familiar to every geologist who has examined any great

*

Humboldt has insisted on the fact, that in double chains of mountains, such as form large portions of the Andes, the lofty parts of one line correspond with the lower parts of the other. Such symmetry of structure is hardly conceivable on the idea of mountains having been formed by paroxysmal violence; but if we consider the whole range as the effect of a widely-extended elevation, prolonged during many ages, it is easy to understand, that if one line be weak, and consequently be subjected, for a long time, to disturbance from the subterranean force, it is probable that during so much the less time will the parallel and approximate one be affected.

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mountain-chain.* I must here add, that according to these views, which I believe are correct, the theoretical part of the foregoing argument, namely the difficulty of confining during any paroxysmal movement the fluid matter within the crust, is weakened; yet I believe the principle holds good, for, in order to break up and throw over portions of very thick crust, as in Diagram 3, there must have been great horizontal extension, and this, if sudden, would have caused as many continuous outbursts of volcanic matter, as there now are axes of solid rock. Moreover, when we consider, first, that the fragments must have stood for one instant separate from each other, and, secondly, that the force necessary to turn over and crush together at one effort these immense masses, must have been in proportion enormously great to that required merely to lift them,—it cannot, I think, be doubted for a moment, that if the force had acted suddenly, these portions of the earth’s crust would have been absolutely blown off, like fragments of rock by gunpowder; but this has not happened, and, therefore, the force did not act suddenly.† If we grant that the earthquake of Concepcion on the 20th of February marked one step in the elevation of a mountain-chain; then, as during the twelve succeeding days there were counted upwards of three hundred shocks, which proceeded from the same quarter with the great shock, so the fluid stone |629| must have been pumped into the axis by as many separate strokes; nor did the process cease for many subsequent months.‡ In the central ridges of the Cordillera, there are masses of compact unstratified rocks, half again as lofty as Etna, and I believe, from the reasoning above given, that they were formed by steps nearly as slow as those indicated by the innumerable layers of volcanic matter accumulated on the flanks of the Sicilian mountain. In the volcano, that is, a mountain which has been ruptured in its incipient state, the fluid stone being brought to the surface is rapidly cooled, and hence successive layers are formed; but in the axis of plutonic formation (or subterranean volcano, if it may be so called), the injected matter, not being rapidly cooled, is blended into one huge conical pile. This whole view is nothing more than an application of Hutton’s10 doctrine of the repetition of small causes to produce great effects; and which Mr. Lyell has already brought distinctly to bear on this particular subject. The action of the elevatory force, as known by beds of littoral shells, successive lines of aqueous erosion on cliffs of solid rock, and terraces rising one above another, seems *

†

‡

In the Cordillera, the axis of plutonic rock is less exposed in the principal, than in the subordinate lines; some strongly marked exceptions, however, occur. In the former, also, the strata are most inclined. As, according to the views here advocated, the formation of a mountain-chain is due to innumerable impulses, the highest part must generally have felt the greatest number of impulses, and therefore its stratification would generally be most disturbed. And if a great part of the disturbance be due to the lateral force resulting from the compression of the great thick portions of the earth’s crust, then the central lines, or those which have several ridges on both sides of them, would be most crushed together, and consequently the strata would be most closely packed over them. I can understand on no other principle, the circumstance of the rock of the axis being visible not on the loftiest, but on the secondary lines of a mountain-range, which very frequently occurs. Mr. Hopkins moreover argues, (Abstract of a Memoir on Physical Geology, p. 15,) that if the elevatory force had the character of an impulsive action, it “would produce the most irregular phenomena, and such as would be altogether without the sphere of calculation. I exclude, therefore, the hypothesis of this kind of action, not as involving in itself any manifest improbability, but as inconsistent with the existence of distinct approximations to general laws in the resulting phenomena.” In other parts the author shows that such approximations do exist in nature.—See also Phil. Mag. 1836, Vol. viii. p. 234. [Hopkins 1836.] In an extract from a letter, dated Concepcion, May 6th, that is seventy-six days after the great earthquake, there is this passage:—“It is only since a few days, that a day has passed without a shock, and even yesterday we had one.”

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everywhere to have been prolonged, although intermittently: in the volcano, the structure of the mountain, as well as all history, bespeaks the same fact with respect to the eruptive force. During the Concepcion earthquake, we have seen that these powers, so analogous in their action, were absolutely parts of one common phenomenon. Bearing in mind Mr. Hopkins’s demonstration, if there be considerable elevation, there must be fissures, and, if fissures, almost certainly unequal upheaval, or subsequent sinking down,—the argument may be finally thus put:—mountain-chains are the effects of continental elevations; continental elevations and the eruptive force of volcanos are due to one great motive power, now in progressive action; therefore the formation of mountain-chains is likewise in progress, and at a rate which may be judged of by either phenomenon, but most nearly by the growth of volcanos. Concluding Remarks With these views, if we look at a map of America, and observe the continuity of the great chain of the Andes, and its lesser parallel ones, in which from lat. 55° 400 South to 60° North, a space of little less than 7000 miles, the volcanic forces either now are, or recently have been, in action,—and likewise the symmetry of the whole,—we shall be deeply impressed with |630| the grandeur of the one motive power, which, causing the elevation of the continent, has produced, as secondary effects, mountain-chains and volcanos. The same reasons which led me to the conviction, that the train of connected volcanos in Chile and the recently uplifted coast, together more than 800 geographical miles in length, rested on a sheet of fluid matter, are applicable with nearly equal force to the areas beneath the other trains. We see that these areas are connected by one uniform chain of mountains, from many distant points of which fluid rock is yearly ejected; and as there are proofs that nearly the whole west coast of South America has been elevated within a period geologically modern, and that this movement, in some parts at least, has extended across the continent,—keeping, also, in mind the probability, that during periods of increased subterranean action, such as those indicated in the foregoing tables, the whole western part of the continent has been almost simultaneously affected, it appears to me, that there is little hazard in assuming, that this large portion of the earth’s crust floats in a like manner on a sea of molten rock. Moreover,—when we think of the increasing temperature of the strata, as we penetrate downwards in all parts of the world, and of the certainty that every portion of the surface rests on rocks which have once been liquefied;—when we consider the multitude of points from which fluid rock is annually emitted, and the still greater number of points from which it has been emitted during the few last geological periods inclusive, which, as far as regards the cooling of the rock in the lowest abysses, may probably be considered as one, from the extreme slowness with which heat can escape from such depths;—when we reflect how many and wide areas in all parts of the world are certainly known, some to have been rising and others sinking during the recent æra, even to the present day, and do not forget the intimate connexion which has been shown to exist between these movements and the propulsion of liquified rock

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to the surface in the volcano;—we are urged to include the entire globe in the foregoing hypothesis. To the belief in these large seas of molten rock, not to speak of an entire concentric layer so constituted, it has been objected, that if its fluidity be tolerably perfect, (which there is good reason to think is the case from what we see of the junction of the plutonic with the metamorphic formations,) the lava ought to stand (supposing a comparative examination possible) at nearly equal heights, within neighbouring volcanic orifices. To this I may answer, if it be permitted me to assume that the subsiding as well as the rising areas rest on a fluid surface, that whatever the power is which causes one to rise and another to sink, acts with unequal force (greatly modified, also, by unequal resistance) in different parts of even a very limited area. The main strength of the earthquake |631| of February 20th, 1835, passed over Valdivia, but affected the districts north and south of it; and it appears that this town, until November 1837, had been less injured by the innumerable shocks which devastated Chile than any other; yet the subterranean abysses directly beneath it are in connexion (as shown by the action of Villarica in 1822) with the district to the North, which has been so often convulsed; and in November 1837, at the same time that an island far southward was upraised eight feet, it was shaken by an earthquake so violent that it escaped utter ruin only from the houses being built of wood. The comparative freedom from disturbance of Valdivia on the 20th of February, cannot be attributed to the action of Villarica, for we have seen that this volcano was quiet; nor indeed is there any reason why such an effect should be attributed to its action, since the eruptions of Osorno and Minchinmadom did not save the northern parts of Chiloe, though they occupy the same relative situation with regard to them, which Valdivia does to Villarica. Shall we then say, that Valdivia escaped so long the subterranean disturbances, some of which affected simultaneously regions north and south of it, solely on account of the greater strength of the crust in that part? This appears to me a cause quite inadequate; and the direct supposition is better, that as within the same period one part of the continent has been elevated more than another, so the lava has been propelled by the action of this force more powerfully towards some, than towards others, of the volcanic orifices which penetrate it. The secular shrinking of the earth’s crust has been considered by many geologists a sufficient cause to account for the primary motive power of these subterranean disturbances; but how it can explain the slow elevation, not only of linear spaces, but of great continents, I cannot understand. With the same view, some highly important speculations have recently been advanced,—such as changes of pressure on the internal fluid mass, from the deposition of fresh sedimentary beds, and even the attraction of the planetary bodies on a sphere not solid throughout; but we can see that there must be many agents, modifying all such primary powers; and the furthest generalization, which the consideration of the volcanic phenomena described in this paper appears to lead to, is, that the configuration of the fluid surface of the earth’s nucleus is subject to some change,—its cause completely unknown,—its action slow, intermittent, but irresistible.

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1

2

123

This is the revised version of Darwin 1838, F1649. (p. 40) It was one of his most important geological papers in which he argued for the progressive long-term changes to the geology of South America due to incremental, non-catastrophic causes. Caldcleugh 1836.

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Charles D. Douglas, surveyor and resident of Chiloé. See letter in CCD1: 575. See Beagle diary, p. 292. J. J. Coste, French privateer. 1836 is presumably a misprint for 1830. Byerbache may be a mistake or a misprint. Possibly ‘Beyerbach’. Cosme Bueno (1711–98), Spanish-born physician and naturalist resident in Peru. Bueno 1738–96. Journal of researches, p. 369. James Hutton (1726–97), Scottish natural philosopher and geologist who proposed what would later be called a uniformitarian view of geological history in his Theory of the earth (1795).

1840. On the formation of mould. By Charles Darwin, Esq., F.R.S., SEC. G.S. [Read 1 November 1837] Transactions of the Geological Society (Ser. 2) 5 (2): 505–9. F16551 The formation of the superficial layer of earth, commonly called vegetable mould, offers some difficulties in being fully understood, which apparently have been overlooked. In old pasture lands, the mould, to the depth of a few inches, differs but slightly, although resting upon various kinds of sub-soil. The uniform fineness of its particles is one of its chief distinguishing characters; and this may be well observed in a gravelly country, where a recently ploughed field immediately adjoins another, which has long remained undisturbed for grazing. In the latter, not a pebble will be seen, either on the surface or immediately below it; although in the ploughed field, a large proportion of the soil may be composed of small stones. From the prevailing use of the expression “vegetable mould,” it would appear that its origin is generally attributed to some effect of vegetation; yet it is scarcely conceivable that the turf, in the case of the two adjoining fields, can have produced so remarkable a difference as that alluded to. My attention was called to this subject by Mr. Wedgwood,2 who showed me, whilst I was staying at Maer Hall, in Staffordshire, several fields, some of which a few years previously had been covered with lime, and others with burnt marl and cinders. These substances, in every case, were buried some inches beneath the turf. In several parts of three grazing fields, I dug square holes, and obtained the following results:—1st. In some good pasture land which had been limed, without having been ploughed, about ten years before, the turf, or the layer in which the roots of the grasses are closely woven together, was about half an inch thick. At two inches and a half beneath this, or about three from the surface, a layer of lime, or a row of small aggregated lumps of it, formed a well-marked white line around the holes. The soil beneath this layer of lime was gravelly, or of a coarse sandy nature, and differed considerably from the mould nearer the surface. About three years ago cinders also had been spread on this field; but when I examined it, they were buried at the depth of one inch. They were not sufficiently numerous to form a layer, though a line of black spots could clearly be traced |506| parallel to and above the white one of lime. Some other cinders, which had been scattered in another part of this same field, only about half a year before, lay either on the surface or were entangled in the roots of the grass.

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The second field, I mention only from the fact of the cinders being buried in such quantities, about three inches deep, as to form a stratum nearly one inch in thickness. The layer in some parts was so continuous, that the upper soil was united to the lower only by the longer roots of the grasses. The sub-soil was a red clay, and it occurred a little below the cinders. The third case which I shall describe, is that of a field which, Mr. Wedgwood informed me, was waste land fifteen years ago. It was at that time drained, ploughed, harrowed, and well covered with burnt marl and cinders. It has not been disturbed since, and now supports a tolerably good but rather coarse pasture.

The section in this field, as represented in the wood-cut, was, turf half an inch; vegetable mould two inches and a half; a layer, one and a half inch thick, of fragments of burnt marl, (conspicuous from their bright red colour), of cinders, and a few quartz pebbles, mingled with earth. One of the angular fragments of burnt marl lying near the bottom, measured one inch in length by half an inch in breadth, and a quarter in thickness. Lastly, about four inches and a half below the surface, was the original black peaty soil. We thus find, beneath a layer, nearly four inches thick, composed of |507| fine particles of earth mixed with decayed vegetable matter, those substances which had been spread on the surface fifteen years before. The appearance in all the above cases was, as if (in the language of the farmers, who are acquainted with these facts) the fragments had worked themselves down. It is, however,

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scarcely possible that cinders or pebbles, and still less powdered quick-lime, could sink through compact earth and a layer of matted roots of vegetables, to a depth of some inches; nor is it at all probable that the decay of the grass, although adding to the surface some of the constituent parts of the mould, should separate in so short a time the fine from the coarse earth, and accumulate the former on those objects, which so lately had been on the surface. I may add, that I have repeatedly observed fragments of pottery and bones buried beneath the turf, in fields near towns, (on which such substances are often thrown with manure); and as these fields did not appear to have been ploughed, the circumstance often surprised me. On the contrary, I have noticed in gardens lately dug, that the rain, by washing away the finer particles, leaves stones and other hard bodies accumulated on the surface. The explanation of these facts, which occurred to Mr. Wedgwood, although it may appear trivial at first, I have not the least doubt is the correct one, namely, that the whole operation is due to the digestive process of the common earth-worm. On carefully examining between the blades of grass in the fields above described, I found scarcely a space of two inches square without a little heap of the cylindrical castings of worms. It is well known, that worms, in their excavations, swallow earthy matter, and that, having separated the portion which serves for their nutriment, they eject at the mouth of their burrows the remainder in little, intestine-shaped heaps. These partly retain their form until the rain and thaws of winter, as I have observed, spread the matter uniformly over the surface. The worm is unable to swallow coarse particles, and as it would naturally avoid pure or caustic lime, the finer earth lying beneath the cinders, burnt marl, or lime, would be removed, by a slow process, to the surface. This supposition is not imaginary; for in the field in which cinders had been spread out only half a year before, I actually saw the castings of the worms heaped on the smaller fragments. Nor, I repeat, is the agency so trivial as at first it might be thought: the great number of earth-worms, as every one must be aware who has ever dug in a grass field, making up for the insignificant quantity of the work which each performs. On the idea of the superficial mould having been thus prepared, the advantage of old pasture land, which it is well known farmers in England are particularly averse to break up, is explained; for the length of time required |508| to form a thick stratum must be considerable. In the peaty field, in the course of fifteen years, about three inches and a half had been well prepared; but it is probable that the process is continued, though at a very slow rate, to a much greater depth. Every time a worm is driven, by dry weather or any other cause, to descend deep, it must bring to the surface, when it empties the contents of its body, a few particles of fresh earth.* Thus the manures added by man, as well as the original constituent parts *

Mr. W. Lindsay Carnagie of Kimblethment, writing from Scotland to Mr. Lyell on the subject of this paper, as it is given in the Proceedings, states, that in clearing away a stiff clayey soil above a stone quarry, he has seen worms in small chambered passages between seven and eight feet below the surface. [William Fullerton Lindsay-Carnegie (1788–1860), Scottish industrialist.] The black mould on the clay was there two feet thick. Mr. Carnagie observes, also, in his letter, that the Scotch farmers, from a belief that the lime itself has some tendency to sink, are afraid of putting it on ploughed land until just before it is laid down for pasture. He then adds, “Some years since, in autumn, I laid lime on an oat-stubble and ploughed it down; thus bringing it into immediate contact with the dead vegetable matter, and securing its thorough mixture through the means of all subsequent operations of fallow; I was considered, in consequence of the above prejudice, to have committed a great fault, but the result was eminently successful, and the practice partially followed. By means of Mr. Darwin’s observations, I think the prejudice will be entirely removed.”—June 1838.

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of the soil, become thoroughly mingled, and a nearly homogeneous character is given to the whole. Although the conclusion may appear at first startling, it will be difficult to deny the probability, that every particle of earth forming the bed from which the turf in old pasture land springs, has passed through the intestines of worms; and hence the term “animal mould” would in some respects be more appropriate than that of “vegetable mould.” I may conclude by remarking, that the agriculturist in ploughing the ground follows a method strictly natural; he only imitates in a rude manner, without being able either to bury the pebbles or to sift the fine from the coarse earth, the work which nature is daily performing by the agency of the earth-worm. Note.—Since my communication on the “formation of mould,” read on the 1st of November, I have received from Staffordshire an account which corroborates the statements then made, on the apparent sinking of objects placed on the surface of turf land. The first case I mention only because the substance is different from those previously described. In the spring of 1835 a boggy field, which had long remained as grass land, was so thickly covered with sand that the whole surface appeared of a red colour. At the present time, namely about two years and a half afterwards, the sand forms |509| a layer three-fourths of an inch below the surface, that thickness consisting of peaty soil. The second case is more interesting. It has been ascertained that a field, which has since been ploughed, was covered about eighty3 years ago with marl; an imperfect layer of it, but sufficiently distinct to be traced, is now found at a depth, very carefully measured from the surface, of twelve inches in some parts and fourteen in others: the difference corresponding to the top and hollow of the ridges produced by ploughing. It is certain, the marl must have sunk or been buried before the field was ploughed, for otherwise the fragments would have been scattered in the soil: this conclusion, moreover, explains the circumstance of the layer being horizontal, whilst the surface is undulating. At the present time no plough could possibly touch the marl, as the land in this country is never turned up to a greater depth than eight inches. In the preceding communication, I have shown, that in a field lately reclaimed from being waste land, three inches of mould had been prepared by the worms in the course of fifteen years. We now find, that within the period of less than eighty years, (but how much less cannot be told, unless the date when the field was first ploughed were known) the earth-worms have covered the marl, which was originally strewed on the surface, with a bed of earth of an average thickness of no less than twelve or thirteen inches. November 14, 1837.

1

2 3

See Darwin 1838, F1648. (p. 48) This topic later culminated in CD’s final book Earthworms (1881) as he wrote in his Autobiography p. 136: ‘It is the completion of a short paper read before the Geological Society more than forty years ago, and has revived old geological thoughts.’ Josiah Wedgwood II (1769–1843), CD’s maternal uncle and father-in-law. CD later corrected this estimate to 30 years in Darwin 1844, F1665 (p. 173).

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1840. [Notes on Chilean beetles.] In Waterhouse, G. R., Description of a new species of the genus Lophotus, from the collection of Charles Darwin, Esq. Annals and Magazine of Natural History 5 (July): 330, 332. F2010 [Lophotus vitulus taken in Tres Montes, Chile] “found on a bare granite mountain, at an elevation of 2500 feet.” |332| [Lophotus eschscholtzi from Valparaiso, Chile] “it first appears in November, is very abundant, and injurious to the young shoots of plums and peaches.” 1841. Queries respecting the human race, to be addressed to travellers and others. Drawn up by a Committee of the British Association for the Advancement of Science, appointed in 1839. Report of the British Association for the Advancement of Science, at the Glasgow meeting, August 1840. 10: 447–58. F19751

1

The committee, appointed at the meeting of 1839, consisted of CD, James Cowles Prichard (1786–1848), physician and ethnologist, Thomas Hodgkin (1798–1866), physician, James Yates (1789–1871), Unitarian clergyman and naturalist, John Edward Gray (1800–75), botanist and zoologist, Richard Taylor (1781–1858), naturalist and publisher, Nicholas Wiseman (1802–65), Roman Catholic clergyman, and William Yarrell (1784–1856), London stationer and naturalist. See Browne 1995, p. 421. The list includes 89 questions, here omitted. Offprints were distributed and a revised version also appeared in the report of the Association in 1842.

1841. [Notes on South American beetles.] In Waterhouse, G. R., [Descriptions of Some New Coleopterous Insects from the Southern Parts of S. America, Collected by C. Darwin, Esq. and T. Bridges, Esq.] Proceedings of the Zoological Society of London 9: 110. F2016 [Nyctelia puncticollis] Several specimens of this species were collected at Bahia Blanca by Mr. Darwin, who says they are ‘tolerably abundant on sand-hillocks.’ |128| Mr. Darwin found this Curculio [Cylydrorhinus angulatus] ‘lying dead by thousands on all parts of the plains at St. Julian, both far in the interior and near the coast.’ 1841. On the distribution of erratic boulders and on the contemporaneous unstratified deposits of South America. By Charles Darwin, Esq., F.R.S., F.G.S. [Read 5 May] Proceedings of the Geological Society of London Part 2, 3: 425–30. F16571 The extensive regions more particularly noticed in this paper are the plains traversed by the Rio Santa Cruz (lat. 50° S.); Tierra del Fuego, including the coasts of the Strait of Magellan, and the Island of Chiloe (lat. 43° S., long. 73° W.).

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Patagonia.—Between the Rio Plata and the Rio Santa Cruz, Mr. Darwin did not observe any boulders, and the only one he noticed in ascending the first 100 miles of the latter river was a mass 7 feet in circumference, about 57 miles from its mouth, or 100 from the Cordillera. At 100 miles from the coast, or 67 from the nearest slope of the Cordillera, transported blocks first occur, and 12 miles nearer the chain they are extraordinarily numerous, consisting of clay-slate, felspathic rocks, chlorite schist and basaltic lava. They are generally angular, and some of them are of immense size, one being 60 feet in circumference, and projecting from 5 to 6 feet above the surface of the ground. The vast open plain on which they lie scattered, is here 1400 feet above the level of the sea, and its surface is somewhat irregular, owing partly to denudation and partly to the protrusion of hummocks and fields of lava. The plain slopes gently and regularly towards the Atlantic, where the sea-cliffs are about 800 feet high; but towards the Cordillera it rises more abruptly, attaining near the chain an elevation of 3000 feet. |426| The highest peaks of the Cordillera in this part of its range do not exceed 6400 feet above the level of the sea. The following section, exhibited in the banks of the Santa Cruz in longitude 70° 500 W., is given by Mr. Darwin to illustrate the nature of the plain on which the boulders rest. feet. 1. 2. 3.

Gravel, or well-rounded shingle,2 coarsely stratified, bearing chiefly on its surface great angular erratic blocks . . Basaltic lava . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Variously coloured thin strata, the lower ones containing minute pebbles of the same nature as the boulders, with the exception of the lava . . . . . . . . . . . . . . . . . . . . .

Bed of the Santa Cruz, above the level of the sea . . . . . . . . .

212 322 588 — 1122 280 — 1402

The shingle bed (1.) extends uninterruptedly to the coast, where it is certainly of submarine origin; and from the general similarity of its nature, Mr. Darwin is of opinion, that it was all accumulated under the same circumstances. The contrast in the means of transport between the deposits (3.) and (1.), the former consisting of fine particles and the latter of large pebbles and immense blocks of the same rocks with the former, is noticed by Mr. Darwin as an interesting circumstance. The valley of the Santa Cruz widens, on approaching the Cordillera, into an estuary-like plain, which has an elevation of only 440 feet; and it is believed by Mr. Darwin to have been submerged within the post-pleiocene period, because existing sea-shells were found near the mouth of the plain, and because terraces, which, near the coast, certainly are of recent submarine origin, extend far up the valley. Around this estuary-like plain, and between it and the great high plain, is a second plain, 800 feet in height, the surface of which, as well as the

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bed of the river in this part, consists of shingle with great boulders. Some of these are of granite, sienite and conglomerate, rocks, which were not observed by Mr. Darwin on the high plain; and on the contrary, the boulders of basaltic lava which were so numerous there, were entirely absent from this lower plain and the river-course. From these circumstances, and likewise from the immense quantity of solid matter which must have been removed in excavating the valley of the Santa Cruz, the author infers that the boulders on the intermediate plain and in the bed of the river, between 30 and 40 miles from the Cordillera, are not derived from the wreck of the high plain, but were transported from the Cordillera subsequently to the modelling of the country, and within, or not long before, the period of existing shells. Mr. Darwin did not observe erratic blocks in any other part of Patagonia, but he states, on the authority of Capt. King,3 that large fragments of primary rocks occur on the surface of the great plain which terminates at Cape Gregory, in the Strait of Magellan. |427| Tierra del Fuego, and Strait of Magellan.—The eastern portion of Tierra del Fuego is formed of large outliers of the Patagonian formation, fringed by deposits of more recent origin. These lower plains, varying in height from 100 to 250 feet, have been elevated within the post-pleiocene period; and they consist of finely grained argillaceous sandstone arranged in thin horizontal or inclined laminæ, and often associated with curved layers of gravel. On the eastern borders of the Straits of Magellan, and at Elizabeth Island, Cape Negro, Nuestra Señora de Gracia, all within the Straits, as well as along the line of coast extending to Port Famine, the sandstone passes into, or alternates with, great unstratified deposits, either of an earthy nature and whitish colour, or of a hardened coarse-grained mud of a dark colour, both containing angular and rounded fragments as well as great boulders of sienite, greenstone, felspathic rocks, clay-slate, hornblende-slate, and quartz. These are arranged without the slightest indication of order, and are derived from mountains at least 60 miles distant to the west or south-west. Sometimes the mass is divided by beds of stratified shingle. North of Cape Virgins, near the entrance of the Strait, it alternates with beds of argillaceous, horizontally laminated sandstone, often thinning out and becoming curvilinear at each end. The inclosed fragments must, in this case, have been transported at least 120 miles. Though Mr. Darwin observed only two boulders imbedded in this deposit, yet as he did not notice any scattered on the surface of the country, he concludes that the boulders which occur in vast numbers on all the beaches have generally been washed out of the cliffs: in St. Sebastian’s Bay, however, on the east coast of Tierra del Fuego, he found many blocks in a protected position at the base of a naked cliff 200 feet high, entirely composed of thin strata of finely grained sandstone; he therefore infers that, in this instance, they must have been derived from a thin superficial deposit. From the form of the land where these boulders occur, it is clear, Mr. Darwin states, that long anterior to the present total amount of elevation, a wide channel must have connected the middle of the Strait of Magellan with the Atlantic; and from the occurrence of boulders on the low neck of land near Elizabeth Island, that at the same period a straight channel must have existed between Otway Water and the eastern arm of the Strait. As the present currents off Cape Horn set from the west, Mr. Darwin says, it is probable that the ancient currents had a similar direction, and this

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inference, he adds, is in accordance with the fact, that the boulders and smaller fragments have been transported from mountains to the west. Navarin Island, and several adjacent islets off the extreme southern parts of Tierra del Fuego, are fringed at about an equal height by an unstratified boulder deposit, very similar to that of the Strait of Magellan; and in Beagle Channel, which separates Navarin Island from Tierra del Fuego, it occasionally alternates regularly with layers of shingle. This extensive deposit resembles, Mr. Darwin states, the “Till” of Scotland, and the boulder formation of Northern Europe and the |428| East of England. The interstratification of regular beds, the occasional appearance of stratification in the mass itself, the juxta-position of rounded and angular fragments of various sizes and kinds of rock derived from distant mountains, and the frequent capping of gravel, indicate some peculiar but similar origin in this deposit of the above widely separated regions. Mr. Darwin follows Mr. Lyell in believing that floating ice, charged with foreign matter, has been the chief agent in its formation; but he adds that it is difficult to understand how the finest sediment was arranged in horizontal laminæ, and coarse shingle in beds, while stratification is totally, and often suddenly, wanting in the closely neighbouring till, if it be supposed that the materials were merely dropped from melting drift ice; and he is disposed to think that the absence of stratification, as well as the curious contortions described in some of the stratified masses, are mainly due to the disturbing action of icebergs when grounded. He believes also that the total absence of organic remains in these deposits may be accounted for by the ploughing up of the bottom by stranded icebergs, and the impossibility of any animal existing on a soft bed of mud or stones under such circumstances. In confirmation of the disturbing action of icebergs, Mr. Darwin refers to Wrangell’s4 remarks on their effects off the coast of Siberia. Chiloe.—North of latitude 47° and between it and the southern extremity of Chiloe, the author landed at several points, but saw no boulders; and he explains their absence by the coast being at a distance from the Cordillera, and separated from it by intervening high land. At Chiloe erratic boulders, often of great size and consisting of granite and sienite, occur in vast numbers along the whole line of the eastern and northern beaches, as well as on the islets parallel to the eastern coast, and on the land at the height of upwards of 200 feet; but the author did not observe any on the western coast at the two points which he examined, nor during an excursion of 30 miles across the high central portion of the island. Chiloe consists, as far as Mr. Darwin ascertained, of mica-slate and volcanic formations, extensively bordered, but chiefly on the eastern and northern sides, by a horizontally-bedded tertiary sandstone and volcanic grit. On the eastern coast, the land is indistinctly modelled into successively rising plains, the surfaces of the upper and the whole thickness of some of the lower being in general composed of stratified shingle. A few boulders occur in this gravel; and as the shores have been extensively denudated, Mr. Darwin infers that most of the very numerous blocks on the beaches were originally included in it. At the northern end of the island, the granitic and sienitic boulders are intermingled, but 30 miles to the southward, the author noticed only granite blocks. The parent rock he believes lies in the Cordillera; and several of the varieties of granite and sienite at the northern end of the island are stated, on the authority of an intelligent resident, to form whole mountains in Reloncavi

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Sound, on the opposite part of the main land. The larger masses were quite angular, and resembled fragments at the foot of a mountain. One block measured |429| 15 feet in length, 11 in breadth, and 9 in height; another, of a pentagonal form, 11 feet on each side, and at one part projected 16 feet above the sand, in which it was partly buried. At the extreme northern point of Chiloe, a headland 250 feet high is joined to Lacuy peninsula by a low neck of land; and from its composition, height and stratification, Mr. Darwin ascertained that it was once continuous with the opposite coast. The boulders were much more numerous on the isthmus and its sides at the height of 150 feet, than on any other part of the surrounding country; and as the sea must have flowed over this isthmus in a channel, previous to the amount of elevation, ascertained to have taken place here within the post-pleiocene period, the position of these boulders proves, according to Mr. Darwin, even more clearly than the cases occurring in Tierra del Fuego, the evident relationship between their distribution and the lines of anciently existing sea-channels. In the southern half of Chiloe, and on one of the Chonos islands, the author discovered a deposit of hardened mud, including far transported, angular and rounded fragments, and resembling the till of the Straits of Magellan. In a layer of loose sand at the base of the cliff in the latter locality, he noticed a quantity of comminuted marine shells with a fresh aspect; and at Chiloe he also observed, at a point where a mass of till passed into finely grained laminæ, small fragments of a Cytheræa.5 With respect to the age of the boulder formation of Chiloe, Mr. Darwin offers no precise remark, but he says that it probably occurs within the post-pleiocene period, because at a height of 350 feet on the peninsula of Lacuy, and therefore considerably above the level of this formation, a great bed of existing sea-shells was observed, and neither the boulder nor accompanying beds appear to have been of deep-water origin. Similar evidence was adduced respecting the age of the till of Tierra del Fuego. North of 41° 470 S. lat., Mr. Darwin did not observe on the Pacific side of South America either boulders or till; nor any north of the Straits of Magellan, on the shores of the Atlantic side; and he accounts for the absence of erratic blocks in the latter region by its great distance from the Cordillera. He is also strongly of opinion that till will be found to be limited to the latitudes in which true boulders occur. Glaciers, &c.—In the concluding part of his memoir, the author offers a few remarks on the glaciers of Tierra del Fuego, and on the transport of the boulders. He did not disembark on any glacier, but in the Beagle and Magdalen channels he passed within 2 miles of several. The mountains were covered with snow, and the glaciers formed many short arms, terminating at the beach in low perpendicular cliffs of ice. Their surface, to a considerable height on the mountains, was perfectly clean and of a bright azure colour; and the former condition he ascribes to their shortness, to their not being flanked by overhanging precipices, and to their not being formed by the junction of two or more smaller streams. The descent of the glaciers, Mr. Darwin states, cannot be very slow, as vast masses continually break off with a great noise, and produce a tumultuous |430| surf on the adjacent beaches. The glaciers in the Beagle Channel were generally bordered by a tongue of land composed of huge fragments of rock, and many boulders were strewed on the neighbouring shores. The glacier which he approached most closely descended to the head of a creek formed on one side by a wall of

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mica-slate, and on the other by a broad promontory from 50 to 60 feet high, on which he landed: it appeared to consist entirely of enormous masses of granite. This promontory, he conceives, was once a lateral moraine, and as it projects nearly half a mile beyond the extremity of the glacier, and is covered with old trees, he infers that the glacier has diminished in length to that extent. Mr. Darwin says it is impossible to explain the distribution of boulders without the agency of ice, but he adds, that neither the till of the Strait of Magellan which passes into, and is irregularly interstratified with, a laminated sandstone containing marine remains, nor the stratified gravel of Chiloe, can have been produced like ordinary moraines. The boulders, likewise, on the lower levels at the head of the Santa Cruz river, he considers, could not have been distributed in their present position by glaciers, the surface having been modelled by the action of the sea; and the little inclination of the high plain from the ridge of the Cordillera to where the boulders occur, as well as the absence of mounds or ridges on it, and the form of the fragments, render it very improbable that they were propelled from the mountains by ancient glaciers. Hence, he concludes, that the blocks of Tierra del Fuego and Chiloe were certainly transported by floating ice, and most probably those of the low and high plains of Santa Cruz. Finally, he is of opinion, from the general angularity of the blocks, and from the present nature of the climate of the southern parts of America, which favours the descent of glaciers to the sea in latitudes extraordinary low, that it is more probable that the boulders were transported on the surface of icebergs, detached from glaciers on the coast, than imbedded in masses of ice, produced by the freezing of the sea.

1

2 3 4 5

In this paper CD defended his and Lyell’s view that floating ice transported boulders far from their native formations rather than Louis Agassiz’s glacier theory. See the revised paper Darwin 1842, F1661 (p. 147). Coarse, rounded stones, larger than gravel, up to 20–25cm in diameter. Philip Parker King (1793–1856), naval officer who commanded the first voyage of Adventure and Beagle. Author of Narrative 1. Ferdinand Petrovich Wrangel (1796–1870), Russian navigator who explored northern waters. CD refers to Sabine 1840. A clam.

1841 [Notes on South American spiders.] In White, A., Descriptions of new or little known Arachnida. Annals and Magazine of Natural History 7 (July): 474, 476. F2011 [Linyphia (Leucauge) argyrobapta] “Web very regular, nearly horizontal, with concentric circles; beneath, but sometimes above, the concentric web, there is, irregular or thin tissue of network; the animal rests in the centre, on the inferior surface: abdomen brilliant; the red colour like a ruby with a bright light behind.” The subgeneric name is one proposed for it in Mr. Darwin’s MSS.

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|476| [Eripus heterogaster] “Evidently, by its structure and habits on the leaf of a tree, species is a Laterigrade; it differs, however, most singularly from that tribe, and is, I think, a new genus. Anterior eyes red; maxillæ rounded, inclined; mentum, thinly arrow-shaped; chelicera powerful, with large aperture for poison; abdomen encrusted with five conical peaks; thorax with one small one; crotchets to tarsi very strong. Colour snow-white, except tarsi and half of leg bright yellow; the tops of the abdominal points and line of eyes black: it must, I think, be new. Taken in the thick forests near Rio de Janeiro, May 1832.”

1841. Humble-bees. Gardeners’ Chronicle no. 34 (21 August): 550. F1658 Perhaps some of your readers may like to hear a few more particulars about the humblebees1 which bore holes in flowers, and thus extract the nectar.2 This operation has been performed on a large scale in the Zoological Gardens:—Near the refection-house there is a fine bed of Stachys coccinea,3 every flower in which has one, and sometimes two, small irregular slits, or orifices, on the upper side of the corolla near its base. I observed some plants of Marvel of Peru, and of Salvia coccinea, with holes in similar positions; but in Salvia Grahami they were without exception cut through the calyx, which is in this species elongated. The tubular corolla of Pentstemon argutus is rather broader than in the above flowers, and two holes are always bored in it by the side of each other, and just above the calyx. All these orifices are so small that they might easily be overlooked; I first noticed them a week since, when, from the brown colour of their edges they appeared to have been made some time before. The beds of Stachys and Pentstemon4 are frequented by numerous humble-bees of many very different kinds; at one moment I saw between twenty and thirty round a bed of the latter flower; they fly very quickly from flower to flower, and always alight with their heads just over the little orifices, into which they most dexterously insert their proboscis and in the case of the Pentstemon, first into the orifice on one side and then into the other, so that they thus extract the nectar on both sides of the germen.5 Besides the humble-bees, I saw some hive-bees on the Pentstemon; they were, however, much less dexterous, and generally alighted across the flower, or on the calyx, and thus lost time. The orifices in all the above-mentioned flowers are made on the upper side of the corolla: I was, therefore, surprised to find, close by, a large bed of the common Antirrhinum6 in which all the flowers had one or two irregular slits, or holes, on the under side of the corolla at its base, close to the small protuberance which represents the spur in Linaria, and therefore directly in front of the nectary at the foot of the germen. From the position of these orifices they cannot be seen without turning up the flower; but the humble-bees seemed to understand this method of picking pockets full as well as the other, and never hesitated where to go, but quickly flew from the under side of one flower to that of another. Now I can speak positively, as far as the experience of part of two summers goes, that country humble-bees are not so cunning, and invariably crawl into the flower by forcing open the elastic lower lip; and a

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very pretty spectacle it is to watch them. All the flowers of Salvia Grahami and the Antirrhinum, which I looked at in different parts of the garden, were bored; and out of the many hundreds in bloom in the two large beds of Stachys and Pentstemon, I could not find one without its little orifice, nor did I see one bee crawl in at the mouth. Nevertheless I found, and the fact appears to me very curious, two separate plants of the Stachys coccinea, and one large one of the Pentstemon argutus, with all their flowers unbored; from the scratches on the lower lip of the flowers of two former plants I have no doubt that many bees had entered in the usual way, and I actually saw one bee crawling into the flowers of the Pentstemon. One is tempted to conjecture that in these plants each humble-bee as it came, not finding a hole ready cut, thought it less trouble to extract the nectar by the mouth than to make one; but that on the beds of the same flowers, where very many bees were rivalling each other in getting honey, some few set to work boring holes, and others copied the example. From the comparative fewness of the hive-bees on the Pentstemon, their evident awkwardness in finding the orifices, and the smallness of their mandibles, I can hardly doubt they were profiting by the workmanship and the example of the humble-bees: should this be verified, it will, I think, be a very instructive case of acquired knowledge in insects. We should be astonished did one genus of monkeys adopt from another a particular manner of opening hard-shelled fruit; how much more so ought we to be in a tribe of insects so pre-eminent for their instinctive faculties, which are generally supposed to be in inverse ratio to the intellectual! Moreover, from what I have above stated regarding the Antirrhinum, I much suspect that the practice of boring holes in its flowers is likewise a piece of acquired knowledge, whether the Humble-bees do it instinctively or not in other cases. Although I have said that country humble-bees appear to be less cunning than London ones, yet I confess I saw this June, in Staffordshire,7 some in the act of cutting holes at the base of the corolla of the Rhododendron azaleoides; the greater number entered the mouth of the corolla, as indeed was evident from the quantity of pollen on the stigma, brought by the bees from neighbouring Azaleas—this hybrid not having a single grain of pollen of its own. One bee was seen which entered the mouth of some of the flowers and cut holes in others; this shows that the orifices are made simply to save trouble, and not because the bee cannot extract the nectar from the long tube. In the Stachys and Pentstemon it is also evident that the bees cut the holes because they can fly much quicker from the upper surface of one flower to that of another, than clamber in on the fringed edge of the lower lip. I have no doubt by this means they are able to visit twice the number of flowers in the same time. Your correspondent (p. 485)8 says that the Honeysuckle is sometimes bored; I never happened to notice this, but I have seen pollen-gathering humble-bees show much skill in forcing open the yet-closed mouth of the young flowers and extracting the pollen; flowers which had been open, apparently even for a day, they at once passed over, whereas the nectar-seeking humble-bees stopped at them. If the mouth of the flower was absolutely close, without any one segment having started, the bees from the difficulty of the attempt immediately gave it up. Your correspondent attributes the failure of his Bean-crop to the apertures made by the bees; but when we remember how the petals of many flowers may be manipulated in hybridising them, without preventing their fructification, we may well doubt this view.

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But I conceive they may be indirectly the cause of the crop failing, not by their making the orifice, but by their not extracting the nectar in the manner nature intended them; for I have observed that when papilionaceous9 flowers are mature, (and actually in the case of the Bean,) bees alighting on the wing-petal, as they always do to reach the nectar at the base of the standard-petal, depress the wing-petals together with the keel, by which movement the grains of pollen together with the stigma are forced out, and both rubbed against one side of the bee’s body, already generally well dusted with the pollen of other flowers of the same species. If all those flowers, even hermaphrodite ones, which are attractive to insects, almost necessarily require their intervention, as is supposed with much probability by Christian Sprengel (Entd. Geheim.),10 to remove the pollen from the anthers to the stigma, what unworthy members of society are these humble-bees, thus to cheat, by boring a hole into the flower instead of brushing over the stamens and pistils, the, so imagined, final cause of their existence! Although I can believe that such wicked bees may be injurious to the seedsman, one would lament to see these industrious, happy-looking creatures punished with the severity proposed by your correspondent.11 Moreover, the florist, I believe, ought rather to praise them for this ingenious method of obtaining the nectar, instead of by the oldfashioned natural one; for let him look how torn and scratched the lower petals of some flowers are—for instance, those of the Mimulus roseus,12 and the wing-petals of some Everlasting-peas. The little orifice which the bees make, in order to avoid clambering in at the mouth, is hardly visible; whereas all the flowers in some beds of the Mimulus, at the Zoological Gardens, are sadly defaced. Let any one who doubts the use of bees in the fructification of hermaphrodite flowers, watch and admire the manner in which the flat surface of the divided stigma of this Mimulus licks the back of the entering bees, which is generally well-dusted already with pollen; and then how admirably the two divisions of the stigma, endowed with a sensitive faculty, close like a forceps on the included granules of pollen! I will only farther remark, that after the facts here noticed, one may well doubt C. K. Sprengel’s view, that the streaks and spots of colour (soft-maal) on the corolla of most nectariferous flowers, serve as guides to insects, that they may readily find out where the nectar-vessel lies. I think the bees which flew so quickly from flower to flower on the under sides of the Antirrhinum, or those which bored the pair of holes on the Pentstemon, or those which bored through calyx and corolla in the Salvia, would tell Mr. Sprengel, that although he might want such aids, they did not. I know hardly any flower which bees open and insert their proboscis into, more rapidly, than the common tall Linaria, which has a little purplish well-closed flower; I have watched one humble-bee suck twenty-four flowers in one minute; yet on this flower there are no streaks of colour to guide these quick and clever workmen.—C. Darwin.

1 2 3

Humble bees = bumble-bees. This is the first of CD’s letters to the Gardeners’ Chronicle. He continued sending occasional letters for the next thirty-six years. CCD2: 300. Previously discussed in Gardeners’ Chronicle in 1841, see pp. 485, 517, 533, 548 and 596. Scarlet Hedgenettle.

1841. On a remarkable bar of sandstone off Pernambuco, on the coast of Brazil 4 5 6 7 8 9

10 11 12

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Beard Tongue. Ovary. Snapdragons. During CD’s visit to Maer, 28 May–1 July. Ruricola 1841. ‘Of a plant or flower: having a corolla arranged in a form resembling a butterfly (as in many leguminous plants such as sweet pea, vetch, broom, etc.), i.e. with a large erect upper petal or standard, two lateral petals or wings, and two narrow lower petals between these fused to form a keel; denoting such a corolla.’ (OED) Christian Konrad Sprengel (1750–1816), German botanist. Sprengel 1793. Ruricola recommended destroying ‘the humble-bees’ nests at the end of the summer, and for children to catch and kill the females … as soon as the first blossoms have expanded.’ Rosy Monkey-Flower.

1841. On a remarkable bar of sandstone off Pernambuco, on the coast of Brazil. By C. Darwin, Esq., M.A., F.R. & G.S. The London, Edinburgh and Dublin Philosophical Magazine (Ser. 3) 19 (October): 257–60. F266 In entering the harbour of Pernambuco, a vessel passes close round the point of a long reef, which, viewed at high water when the waves break heavily over it, would naturally be thought to be of coral-formation, but when beheld at low water it might be mistaken for an artificial breakwater, erected by cyclopean workmen.* At low tide it shows itself as a smooth level-topped ridge, from thirty to sixty yards in width, with even sides, and extending in a perfectly straight line, for several miles, parallel to the shore. Off the town it includes a shallow lagoon or channel about half a mile in width, which further south decreases to scarcely more than a hundred yards. Close within the northern point ships lie moored alongside the reef to old guns let into it.

Transverse section: vertical heights considerably exaggerated A. Level of the sea at low water. B. Subsided masses, thickly coated with Serpulæ,1 &c. C. Summit of the bar, which generally slopes a little seaward; but the slope in the woodcut has been unintentionally somewhat increased. D. Subsided masses of bare sandstone. E. Surface of the harbour or lagoon. |258| * Communicated by the author.

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1841. On a remarkable bar of sandstone off Pernambuco, on the coast of Brazil

The accompanying woodcut represents, at low water spring tides, a transverse section of the northern part of the bar, where a section of about seven feet in height is exhibited on the inner side. It consists of a hard pale-coloured sandstone, breaking with a very smooth fracture, and formed of siliceous grains, cemented by calcareous matter. Well-rounded quartz pebbles, from the size of a bean, rarely to that of an apple, are imbedded in it, together with a very few fragments of shells. Traces of stratification are obscure, but there was an included layer in one spot of stalactitic limestone, an eighth of an inch in thickness. In another place some false strata, dipping landwards at an angle of 45°, were capped by a horizontal mass. On each side of the ridge quadrangular fragments have subsided, as shown in the woodcut; and the whole mass is in some places fissured, apparently from the washing out of some soft underlying bed. One day, at low water, I walked a full mile along this singular, smooth, and narrow causeway, with water on both sides of me, and could see that for nearly a mile further its form remained unaltered. In Baron Roussin’s beautiful chart of Pernambuco (Le Pilote du Brésil)2 it is represented as stretching on, in an absolutely straight line, for several leagues; how far its composition remains the same, I know not; but from the accounts I received from intelligent native pilots, it seems to be replaced on some parts of the coast by true coral reefs. The upper surface, though on a large scale it must be called smooth, yet presents, from unequal disintegration, numerous small irregularities. The larger imbedded pebbles stand out supported on short pedestals of sandstone. There are, also, many sinuous cavities, two or three inches in width and depth, and from six inches to two feet in length. The upper edges of these furrows sometimes slightly overhang their sides; they end abruptly, but in a rounded form. One of the furrows occasionally branches into two arms, but generally they are nearly parallel to each other, and placed in lines transverse to the sandstone ridge. I know not how to account for their origin, without they be formed by the surf, as it daily breaks over the bar, washing to and fro pebbles in depressions, originally only slight. Opposed to this notion is the fact, that some of them were lined with numerous small living Actineæ.3 I have copied this passage, as I at the time wrote it, because furrows of a somewhat similar nature on the surface of rocks have lately received much attention, and are supposed invariably to indicate the former action of a waterfall, over the edge of a moving glacier. The exterior part of the bar is coated with a thin layer of |259| calcareous matter; this, on the outer subsided masses, which can only be reached between the successively breaking waves at low water, is so thick, that I could seldom expose the sandstone with a heavy hammer. I procured, however, some fragments where the layer was between three and four inches in thickness; it consists chiefly of small Serpulæ, including some Balani, and a few very thin paper-like layers of a Nullipora.4 The surface alone is alive, and all within consists of the above organic bodies filled up with dirty white calcareous matter. The layer, though not hard, is tough, and from its rounded surface resists the breakers. Along the whole external margin of the bar, I only saw one very small point of sandstone which was exposed to the surf. In the Pacific and Indian Oceans the outer and upper margin of the coral reefs are protected, as will be described in a forthcoming work,5 by a very similar coating; but there it is almost exclusively formed of several species of Nulliporæ. Lieut. Nelson,6 in his excellent

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memoir on the Bermudas (Geol. Trans., vol. v. part 1. p. 117), has described reefs, formed, as he states, but I cannot avoid suspecting only coated, by similar masses of Serpulæ. I inquired from some old pilots, whether there was any tradition of change in the form and dimensions of this sandstone bar; but they were unanimous in answering me in the negative. It is astonishing to reflect, that although waves of turbid water, charged with sediment, are driven night and day, by the ceaseless tradewind, against the abrupt edges of this natural breakwater, yet that it has lasted in its present perfect state for centuries, or more probably thousands of years. Seeing that the surface on the inner side does gradually wear away, as shown by the pebbles on the sandstone pedestals, this durability must be entirely owing to the protection afforded by the thin coating of Serpulæ and other organic beings: it is a fine example, how apparently inefficient, yet how effectual, are the means of preservation, like those of destruction, which nature employs. I believe similar bars of rock occur in front of some of the other bays and rivers on the coast of Brazil: Baron Roussin states that at Porto Seguro there is a “quay” similar to that of Pernambuco. Spaces of several hundred miles in length on the shores of the Gulf of Mexico, the United States, and southern Brazil are formed by long narrow islands and spits of sand, including very extensive shallow lagoons, some of which are several leagues in width. The origin of these linear islets is rather obscure: Prof. Rogers (Report to British Association, vol. iii. p. 13.)7 gives some reasons for suspecting |260| that they have been formed by the upheaval of shoals, deposited where currents met. These phænomena, it is very probable, are connected in their origin with the same causes which have produced the remarkable bar of sandstone off Pernambuco. The town of Pernambuco stands on a low narrow islet and on a long spit of sand, in front of a very low shore, which is bounded in the distance by a semicircle of hills. By digging at low water near the town the sand is found consolidated into a sandstone, similar to that of the breakwater, but containing many more shells. If, then, the interior of a long sandy beach in one part, and in another the nucleus of a bar or spit extending in front of a bay became consolidated, a small change, probably of level, but perhaps simply in the direction of the currents, might give rise, by washing away the loose sand, to a structure like that in front of the town of Pernambuco, and along the coast southward of it; but without the protection afforded by the successive growth of organic beings, its duration would be short, if indeed it were not destroyed before being completely exhibited.

1 2 3 4 5 6 7

A family of sessile, tube-building, annelid worms in the class Polychaeta. This article was reprinted, without the woodcut, in Coral reefs 2d ed., pp. 265–8. Albin Reine Roussin (1781–1854), French naval officer and diplomat who surveyed the coast of Brazil in 1819. Roussin 1826–7. Sea anemones. Lime-secreting algae, once thought to be animals. Coral reefs (1842). Richard John Nelson (1803–77), army officer and geologist. Nelson 1840. Henry Darwin Rogers (1808–66), American geologist, professor of geology and mineralogy, University of Pennsylvania, 1835–48. Rogers 1835.

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1841. [Note on a ground-beetle found off the Straits of Magellan.] In Waterhouse, G. R., Carabideous insects collected by Charles Darwin, Esq., during the voyage of Her Majesty’s ship Beagle. Annals and Magazine of Natural History 6 (December): 254. F2012 [Cardiophthalmus clivinoides] “found dead in the sea, 40 miles off the Straits of Magellan.”

1842. [Notes on South American beetles.] In Waterhouse, G. R., Carabideous insects collected by Charles Darwin, Esq., during the voyage of Her Majesty’s ship Beagle. Annals and Magazine of Natural History 9 (April): 136–137. F2013 [Abropus splendidus] “These insects live amongst the soft yellow balls which are excrescences, or rather fungi, growing on the Fagus antarctica, and which are eaten by the Fuegians.” |137| [Migadops virescens] “under bark”

1842. [Note on a mushroom from Maldonado.] In Berkeley, M. J., Notice on some fungi collected by C. Darwin, Esq., in South America and the Islands of the Pacific. Annals and Magazine of Natural History 9 (August): 446. F2014 [Clathrus crispus] “Salmon-coloured; brownish-green internally.”

1842. Notes on the effects produced by the ancient glaciers of Caernarvonshire, and on the boulders transported by floating ice. By Charles Darwin, Esq., M.A., F.R.S. and F.G.S. The London, Edinburgh and Dublin Philosophical Magazine 21 (September): 180–8. F16601 Guided and taught by the abstract of Dr. Buckland’s2 memoir “On Diluvio-Glacial Phænomena in Snowdonia and the adjacent parts of North Wales,”* I visited several of the localities there noticed, and having familiarized myself with some of the appearances described, I have been enabled to make a few additional observations. Dr. Buckland has stated that a mile east of Lake Ogwyn3 there occurs a series of mounds, covered with hundreds of large blocks of stone, which approach nearer to the condition of an undisturbed moraine, than any other mounds of detritus noticed by him in North Wales. By ascending these mounds it is indeed easy to imagine that they formed the north-western lateral moraine of a glacier, descending in a north-east line from the Great Glyder mountain. But at the southern end of Lake Idwell4 the phænomena of moraines are presented, though on a much smaller scale, with perfect distinctness. On entering the wild amphitheatre in which Lake Idwell lies, some small conical, irregular little mounds, which might easily *

Read before the Geological Society, December 15th, 1841, and the Abstract is published in the Athenæum, 1842, p. 42. (An Abstract of Dr. Buckland’s paper, from the Proceedings of the Society, will appear in an early number of the Philosophical Magazine.—Edit.)

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escape attention, may be seen at the further end. The best preserved mounds lie on the west side of the great black perpendicular face of rock, forming the southern boundary of the lake. They have been intersected in many places by streams, and they are seen to consist of earth and detritus, with great blocks of rock on their summits. They at first appear quite irregularly grouped, but to a person ascending any one of those furthest from the precipice, they are at once seen to fall into three (with traces of a fourth) narrow straight linear ridges. The ridge nearest the precipice runs someway up the mountain, but the outer one is longer and more perfect, and forms a trough with the mountain-side, from 10 to 15 feet deep. On the eastern and opposite side of the head of the lake, corresponding but less developed mounds of detritus may be seen running a little way up the mountain. It is, I think, impossible for any one who has read the descriptions of the moraines bordering the existing glaciers in the Alps, to stand on these mounds and for an instant to doubt that they are ancient moraines; nor is it possible to conceive any other cause which could have abruptly thrown up these long narrow steep mounds of unstratified detritus against the mountain-sides. The three |181| or four linear ridges evidently mark the principal stages in the retreat of the glacier; the outer one is the longest, and diverges most from the great wall of rock at the south end of the lake. The inner lines distinctly define the boundary of the glacier during the last stage of its existence. At this period a small and distinct glacier descended from a narrow but lofty gorge on the north-western end of the lake; and here remnants of a terminal moraine may be traced in the little mounds, forming a broken semicircle round a rushy plain, scarcely more than a hundred yards in diameter. The rocks are smoothed, mammillated and scored, all round the lake, and at some little depth beneath the surface of the water, as I could both see and feel. Similar marks occur at great heights on all sides, far above the limits of the moraines just described, and were produced at the time when the ice poured in a vast stream over the rocky barrier bounding the northern end of the amphitheatre of Lake Idwell. I may here mention, that about eighty yards west of the spot where the river escapes from the lake, through a low mound of detritus, probably once a terminal moraine, there is an example of a boulder broken, as described by Charpentier and Agassiz, into pieces, from falling through a crevice in the ice. The boulder now consists of four great tabular masses, two of which rest on their edges, and two have partly fallen over against a neighbouring boulder. From the distance, though small in itself, at which the four pieces are separated from each other, they must have been pitched into their present position with great force; and as the two upright thin tabular pieces are placed transversely to the gentle slope on which they stand, it is scarcely possible to conceive that they could have been rolled down from the mountain behind them; one is led, therefore, to conclude that they were dropped nearly vertically from a height into their present places. The rocky and steep barrier over which the ice from the amphitheatre of Lake Idwell flowed into the valley of Nant-Francon, presents from its summit to its very foot (between 400 and 500 feet) the most striking examples of boss or dome-formed rocks; so much so, that they might have served as models for some of the plates in Agassiz’s work on Glaciers.5 When two of the bosses stand near and are separated only by a little gorge, their steep rounded sides are generally distinctly scored with lines, slightly dipping towards the great

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valley in front. The summit of the bosses is comparatively seldom scored; but on one close to the bridge over the river Ogwyn, I remarked some singular zigzag scores. At this spot the cleavage of the slate is highly inclined, and owing apparently |182| to the different degrees of hardness of the laminæ, smooth and gentle furrows have been produced by the grinding of the ice, transversely to the scores, and to the probable course of the glacier. Here, as well as in some few other places, I noticed an appearance which made it vividly clear that these bosses had been formed by some process quite different from ordinary aqueous or atmospheric erosion; it is the abrupt projection from the smooth surface of a boss of a piece of rock a few yards square, and one or two feet in height, with its surface smoothed and scored like the boss on which it stands, but with its sides jagged: if a statuary were to cut a small figure out of a larger one, the abrupt projecting portions, before he quite completed his work, might be compared to these masses of rock: how it comes that the glacier, in grinding down a boss to a smaller size, should ever leave a small portion apparently untouched, I do not understand. On the summit of some of the bosses on this barrier there are perched boulders: but this phænomenon is seen far more strikingly close to Capel-Curig, where almost every dome of rock south of the Inn is surmounted by one or more large angular masses of foreign rock. The contrast between the rude form of these blocks, and the smooth mammillated domes on which they rest, struck me as one of the most remarkable effects produced by the passage of the glaciers. On the sides of the mountains above Capel-Curig, I observed some boulders left sticking on very narrow shelves of rocks, and other boulders of vast size scattered in groups. The largest boulder I noticed there was about 26 feet in length by 12 in breadth, and buried to an unknown thickness. Proceeding down the great straight valley of Nant-Francon, which must formerly have conveyed the united glaciers from Lakes Idwell and Ogwyn, we continue to meet with boss-formed rocks till below the village of Bethesda. From this point towards Bangor these boss-formed rocks become rare; at least it is certain that a large number of hummocks of rock with rugged surfaces project, whereas higher up in this valley, and in all the great central valleys of Snowdonia, such unground hummocks are not to be met with. At Bethesda, unstratified masses of whitish earth, from ten to forty feet in thickness, full of boulders mostly rounded, but some angular, from one to four feet square, are first met with. This deposit is interesting from the boulders being deeply scored, like the rocks in situ over which a glacier has passed. The scores are sometimes irregular and crooked, but generally quite parallel, as I distinctly saw over the entire side of one large block. Some of the blocks were scored only on one side, others on |183| two sides, but from the difficulty of turning over the larger ones, I do not know which case is most common. I saw one large block on which the scores on the opposite sides were all parallel; and another irregularly conical one, four feet in length, of which three-fourths of the circumference was marked with parallel striæ, converging towards the apex. In the smaller elongated blocks, from six to twelve inches in diameter, I observed that the striæ were generally, if not always, parallel to their longer axes, which shows that when subjected to the abrading force, they arranged themselves in lines of least resistance. Out of three large blocks which remained imbedded in a perpendicular

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cliff, the vertical sides of two were scored in horizontal lines, and of the third in an oblique direction. These several facts, especially the parallel striæ on the upper and lower surfaces, show that the boulders were not scored on the spot where they are now imbedded, as seems to have been the case with the boulders described by Mr. Maclaren* in the till near Edinburgh. The contrast is very striking in the state of the surface of these boulders, and those which lie scattered high up on the sides of the adjoining hills and of the great central valleys, or are perched on the worn bosses of naked rock; such boulders, as I particularly noticed, present no signs of scores or striæ, as might have been anticipated, if, as is supposed, they were transported on the surface of the glaciers. In the quarries which I examined, namely, below Bethesda, and at some little height on the eastern side of the village, the till rested on slate-rocks, not worn into bosses. I found, however, a rather smooth pap of greenstone marked with a few deep scores. The till forms, at the height probably of 600 feet above the sea, a little plain, sloping seaward; and between Bethesda and Bangor, there are other gently inclined surfaces composed of till and stratified gravel. Considering these facts, together with the proofs of recent elevation of this coast, hereafter to be mentioned, I cannot doubt that this till was accumulated in a sloping sheet beneath the waters of the sea. In composition it resembles some of the beds of till in Tierra del Fuego, which have undoubtedly had this origin. I presume the scored, rounded, and striated boulders were pushed, in the form of a terminal moraine, into the sea, by the great glacier which descended Nant-Francon. Mr. Trimmer† reports, on the authority of some workmen, |184| that sea-shells have been found on Moel Faban, two miles N.E. of Bethesda. I ascended this and some neighbouring hills, but could find no trace of any deposit likely to include shells. This hill stands isolated, out of the course of the glaciers from the central valleys; it exceeds 1000 feet in height; its surface is jagged, and presents not the smallest appearance of the passage of glaciers: but high up on its flanks (and perhaps on its very summit) there are large, angular and rounded boulders of foreign rocks. Along the sea-coast between Bangor and Caernarvon, and on the Caernarvonshire plain, I did not notice any boss-formed hillocks of rock. The whole country is in most places concealed by beds of till and stratified gravel, with scattered boulders on the surface: some of these boulders were scored. From the account given by Mr. Trimmer‡ of his remarkable discovery of broken fragments of Buccinum, Venus, Natica, and Turbo, beneath twenty feet of sand and gravel, on Moel Tryfan (S.E. of Caernarvon), I ascended this hill. Its height is 1192 feet§ above the sea; it is strewed with boulders of foreign rock, most of them apparently from the neighbouring mountains; but near the summit I found the rounded chalk-flints** and small pieces of white granite alluded to by Dr. Buckland. Its form is conical, and it * †

‡ § **

Geology of Fife and the Lothians, p. 212. [Charles Maclaren (1782–1866), geologist and editor of The Scotsman. Maclaren 1839.] Proceedings of the Geological Society, vol. i. p. 332, or Phil. Mag. S. 2. vol. x. p. 143. Mr. Trimmer was one of the earliest observers of the scores and other marks on the rocks of North Wales. He has also remarked that “some of the larger blocks amid the gravel have deep scratches upon their surface.” Mr. Trimmer himself found broken sea-shells in the diluvium at Beaumaris. [Joshua Trimmer (1795–1857), geologist employed on the Geological Survey of England, 1846–54. Trimmer 1831.] Proceedings of the Geological Society, vol. i. p. 332. (Phil. Mag. loc. cit.) Murchison’s Silurian System, p. 528. [Murchison 1839.] I may mention, that at Little Madely, in Staffordshire, I have found chalk-flints in the gravel-beds, associated with existing species of sea-shells.

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stands isolated: wherever the bare rock protrudes its surface is jagged, and shows no signs of being in any part worn into bosses. The contrast between the superficial part of the bare rock on this hill and on Moel Faban, with that of the rocks within the great central valleys of Caernarvonshire, is very remarkable; it is a contrast of precisely the same kind as may be observed in these same valleys by ascending on either side above the reach of the ancient glaciers. A little way down the hill, a bed two or three feet in thickness, of broken fragments of slate mixed with a few imperfectly rounded pebbles and boulders of many kinds of rock, is seen in several places to rest on the slate, the upper surface of which, to the depth of several feet, has been disintegrated, shattered and contorted in a very curious manner. The laminated fragments, however, sometimes partially retain their original position. I did not succeed in finding any fragments of shells, but near the summit of the hill on the eastern or inland side, I found beds, at least twenty feet in thickness, of irregularly stratified gravel and boulders, with distinct and quite defined layers of coarse yellow sand, and others of a fine argillaceous |185| nature and reddish colour. These beds closely resemble those of Shropshire and Staffordshire, in which are found (as I have myself observed in very many places) fragments of sea-shells, and which every one, I believe, since the publication of Mr. Murchison’s chapters on the drift of these counties, admits are of submarine origin. It may therefore be concluded that the layers of coarse and argillaceous sand, and of gravel, with far-transported pebbles and boulders, do not owe their origin to an inundation, but were deposited when the summit of Moel Tryfan stood submerged beneath the surface of the sea. As there are no marks of the passage of glaciers over this mountain (which indeed from its position could hardly have happened), we must suppose that the boulders were transported on floating ice; and this accords with the remote origin of some of the pebbles, and with the presence of the sea-shells. Within the central valleys of Snowdonia, the boulders appear to belong entirely to the rocks of the country. May we not conjecture that the icebergs, grating over the surface, and being lifted up and down by the tides, shattered and pounded the soft slate-rocks, in the same manner as they appear to have contorted the sedimentary beds of the east coast of England (as shown by Mr. Lyell),* and of Tierra del Fuego? Although I was unable to find any beds on Moel Faban likely to preserve sea-shells, yet, considering the absence of the marks of the passage of glaciers over it, I cannot doubt that the boulders on its surface were transported on floating ice. The drifting to and fro, and grounding of numerous icebergs during long periods near successive uprising coast-lines, the bottom being thus often stirred up and fragments of rock dropped on it, will account for the sloping plain of unstratified till, occasionally associated with beds of sand and gravel, which fringes to the west and north the great Caernarvonshire mountains. In a paper read before the Geological Society,† I have remarked that blocks of rock are transported by floating ice under different conditions; 1st, by the freezing of the sea, in countries where the climate does not favour the low descent of glaciers; 2nd, by the

* †

“On the Boulder Formation of Eastern Norfolk;” Phil. Mag., S. 3, vol. xvi. May 1840, p. 351. [Lyell 1840b.] May 5th. 1841, “On the distribution of the Erratic Boulders, and on the contemporaneous unstratified deposits of South America.” (Phil. Mag. S. 3, vol. xix. p. 536.) [Darwin 1841, F1657 (p. 128).]

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formation of icebergs by the descent of glaciers into the sea, from mountains not very lofty, in latitudes (for instance in that of Geneva, or of the mouth of the Loire, in the southern hemisphere) where the surface of the |186| sea never freezes; and 3rd, by these two agencies united. I have further remarked that the condition and kind of the stones transported, would generally be influenced by the manner of production of the floating ice. In accordance with these views, I may remark that it does not seem probable from the low level of the Chalk-formation in Great Britain, that rounded chalk-flints could often have fallen on the surface of glaciers, even in the coldest times. I infer therefore that such pebbles were probably inclosed by the freezing of the water on the ancient sea-coasts. We have, however, the clearest proofs of the existence of glaciers in this country; and it appears, that when the land stood at a lower level, some of the glaciers, as in Nant-Francon, reached the sea, where icebergs charged with fragments would occasionally be formed. By this means we may suppose that the great angular blocks of Welch rocks, scattered over the central counties of England, were transported.* I looked carefully in the valleys near Capel-Curig and in Nant-Francon for beds of pebbles, or other marks of marine erosion, but could not discover any: when, however, Moel Tryfan and Faban stood beneath the level of the sea, inland creeks of salt-water must have stretched far up or quite through these valleys, and where they were deep, the glaciers (as at present in Spitzbergen)† would have extended, floating on the surface of the water, ready to become detached in large portions. From the presence of boss-formed rocks low down in the valley of Nant-Francon, and on the shores of the Lakes |187| of Llanberis (310 feet above the sea), it is evident that glaciers filled the valleys after the land had risen to nearly its present height; and these glaciers must have swept the valleys clean of all the rubbish left by the sea. As far as my very limited observations serve, I suspect that boss or dome-formed rocks will serve as one of the best criterions between the effects produced by the passage of glaciers and of icebergs.‡ Dr. Buckland has described in detail the marks of the passage of glaciers along nearly the whole course of the great central Welch valleys; I observed that these marks were evident at the height of some hundred feet on the mountain-sides, above the water-sheds, where the streams flowing into the sea at Conway, Bangor, Caernarvon, and Tremadoc, divide: hence *

† ‡

On the summit of Ashley Heath in Staffordshire, there is an angular block of syenitic greenstone, four feet and a half by four feet square, and two feet in thickness. This point is 803 feet above the level of the sea. From this fact, together with those relating to Moel Tryfan and Faban, we must, I think, conclude that the whole of this part of England was, at the period of the floating ice, deeply submerged. From the reasons given in my paper (Phil. Trans., 1839; [Darwin 1839, F1653 (p. 50).] (Phil. Mag. S. 3, vol. xiv. p. 363)), I do not doubt that at this same period the central parts of Scotland stood at least 1300 feet beneath the present level, and that its emergence has since been very slow. The boulder on Ashley Heath probably has been exposed to atmospheric disintegration for a longer period than any other in this part of England. I was therefore interested in comparing the state of its lower surface, which was buried two feet deep in compact ferruginous sand (containing only quartz pebbles from the subjacent new red sandstone), with the upper part. I could not, however, perceive the smallest difference in the preservation of the sharp outlines of its sides. I had a hole dug under another large boulder of dark green felspathic slaty rock, lying at a lower level; it was separated by 18 inches of sand, (containing two pebbles of granite, and some angular and rounded masses of new red sandstone) from the surface of the new red sandstone. One of the rounded balls of this latter stone had been split into two, and deeply scored, evidently by the stranding of the boulder. Dr. Martens on the Glaciers of Spitzbergen, New Edinb. Phil. Journ. 1841, (vol. xxx.) p. 288. In the Appendix to my Journal of Researches (1839), I endeavoured to show that many of the appearances attributed to debacles, and to the movements of glaciers on solid land, would in all probability be produced by the action of stranded icebergs. I have stated (p. 619), on the authority of Dr. Richardson, [John Richardson (1787–1865), Arctic explorer and naturalist. See Darwin 1856–7, F1936. (p. 256)] that the rocky beds of the rivers in North America which convey ice, are smoothed and polished; and that (p. 620) the icebergs on the Arctic shore drive before them every pebble, and leave the submarine ledges of rock absolutely bare.

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it appears that a person starting from any one of these four places (or from some way up the valley where the glacier ended), might formerly, without getting off the ice, have come out at either of the other three places, or low down in the valleys in which they stand. The mountains at this period must have formed islands, separated from each other by rivers of ice, and surrounded by the sea. The thickness of the ice in several of the valleys has been great. In the vale of Llanberis I ascended a very steep mountain, E.N.E. of the upper end of the upper lake, which slightly projects where the valley bends a little. For the lower 1000 feet (estimated, I think, correctly) the marks left by the glacier are very distinct, especially near the upper limit, where there are boulders perched on bosses of rock, and where the scores on the nearly vertical faces of rock are, I think, more distinct than any others which I saw. These scores are generally slightly inclined, but at various angles, seaward, as the surface of the glacier must formerly have been. But on one particular face of rock, inclined at an angle of somewhere about fifty degrees, continuous, well-marked and nearly parallel lines sloped upwards (in a contrary sense to the surface of the glacier) at an angle of 18° with the horizon. This face of rock did not lie parallel to the sides of the main valley, but formed one side of the sloping end of the mountain, over and round which the ice appears to have swept with prodigious force, expanding laterally after being closely confined by the shoulder above |188| mentioned. At this point, where the glacier has swept to the westward, and has expanded, its surface seems in a short space to have declined much: for on a hill lying about a quarter of a mile N.W. of the shoulder, and forming a lower part of the same range (it stands S.S.E. of the Victoria Inn, and has a reddish summit), the marks of the passage of the glacier are at a considerably lower level. At the very summit, however, of this hill, several large blocks of rock have been moved from their places, as if the ice had occasionally passed over the summit, but not for periods long enough to have worn it smooth. I cannot imagine a more instructive and interesting lesson for any one who wishes (as I did) to learn the effects produced by the passage of glaciers, than to ascend a mountain like one of those south of the upper lake of Llanberis, constituted of the same kind of rock and similarly stratified, from top to bottom. The lower portions consist entirely of convex domes or bosses of naked rock, generally smoothed, but with their steep faces often deeply scored in nearly horizontal lines, and with their summits occasionally crowned by perched boulders of foreign rock. The upper portions, on the other hand, are less naked, and the jagged ends of the slaty rocks project through the turf in irregular hummocks; no smooth bosses, no scored surfaces, no boulders are to be seen, and this change is effected by an ascent of only a few yards! So great is the contrast, that any one viewing these mountains from a distance, would in many cases naturally conclude that their bases and their summits were composed of quite different formations.

1

CD spent ten days in North Wales in June 1842 to determine if his floating ice theory would be affected by Buckland’s glacial findings there. CD soon found that glacial action was evident

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2 3 4 5

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but continued to maintain that his theory was a preferable explanation of erratic boulders. CD abandoned these views during the following decades as the effects of glaciation were more widely uncovered. William Buckland (1784–1856), prominent geologist and palaeontologist. Buckland 1841. Or ‘Ogwen’, about 5km west of Capel Curig, North Wales. Idwal. Agassiz 1840.

1842. On the distribution of the erratic boulders and on the contemporaneous unstratified deposits of South America. By Charles Darwin, Esq., M.A., F.R.S. and F.G.S. [Read 14 April 1841] Transactions of the Geological Society Part 2, 3 (78): 415–31. F16611 Contents. in the Valley of the Santa Cruz. . . . . . . . . . . . . in Tierra del Fuego and the Strait of Magellan. . . . in the Island of Chiloe. . . . . . . . . . . . . . . . . . . . .

1. 2.

Description of the Boulder Formation ______________________

3.

______________________

4.

Remarks on the Glaciers of Tierra del Fuego and on the transportal of Boulders. . . . . . . . . . . .

p. 415 p. 417 p. 423 p. 427

1. Boulder Formation in the Valley of the Santa Cruz. During the survey of the shores of South America, southward of the Rio Plato, by Capt. FitzRoy in H.M.S. Beagle, I did not meet with any boulders on the eastern plains of the continent until we arrived on the banks of the river Santa Cruz, in lat. 50° 100 S. Nor did they occur there near the coast, but were first noticed in ascending the river at the distance of about 100 geographical miles from the Atlantic, and 67 from the nearest slope of the Cordillera. Twelve miles further west, in lon. 70° 500 W., that is, fifty-five miles from the mountains, they were extraordinarily numerous; consisting of compact clay-slate, feldspathic rock, a quartzose chloritic schist, and basaltic lava; and they were generally of an angular form, and many of them resembled fragments of rock at the foot of a precipice. The size of some was immense: I measured a square one of chloritic schist, which was five yards on each side and projected five feet above the ground; a second, which was more rounded, was sixty feet in circumference, and stood six feet above the ground; how much of each was buried beneath the surface I could not ascertain. There were innumerable other fragments from two to four feet square. The vast open plain on which they lay scattered, is 1400 feet above the level of the |416| sea; its surface is somewhat but not greatly irregular, and the inequalities appear to have been caused chiefly by the denudation of loose matter from an irregular field and hummocks of lava. The plain slopes very gently and with much regularity to the Atlantic, where the sea-cliffs are about 800 feet high; it rises somewhat more abruptly towards the Cordillera, near which its height is above 3000 feet. The Cordillera

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Fig. 1.

in this latitude are not very lofty, the highest pinnacle being only 6400 feet above the level of the sea. The accompanying section (Fig. 1.), exhibited on the banks of the river in the longitude above referred to, will give a sufficient idea of the composition of the plain on which the boulders lie. The upper bed is 212 feet in thickness, and exhibits indications of being coarsely stratified. It is composed of well-rounded shingle with great angular blocks strewed on the surface, and probably imbedded (for owing to the state of the section I was unable to ascertain this point) in the whole upper part of the stratum. The shingle bed is continued without interruption to the coast, and is there certainly of submarine origin. From its general similarity throughout this space, I have no reason to doubt that the whole was accumulated under similar circumstances. The lowest bed represented in the section is composed of minute pebbles of the same varieties of rock, with the exception of those of basaltic origin, as the great boulders on the surface. The contrast in the means of transportal from the same source, afforded by the regularly sifted minute pebbles of the lowest bed and the huge angular fragments of the uppermost, separated by a great stream of lava and a deposit of fine sediment nearly 500 feet thick, appears to be worthy of notice. The valley in which the Santa Cruz flows, widens as it approaches the Cordillera, into a plain, in form like an estuary, with its mouth (see map, Pl. XL.) directed towards the mountains. This plain is only 440 feet above the level of the sea, and |417| in all probability it was submerged within, or nearly within, the post-pliocene period. I am induced to form this inference from the presence of existing sea shells in the valley, and from the extension far up it of step-like terraces which on the sea-coast, certainly are of recent submarine origin. Round the estuary-like plain, and between it and the great high plain, there is a second plain, about 800 feet above the sea-level, and its surface consists of a bed of shingle with great boulders. In this part of the valley, namely, between thirty or forty miles from the Cordillera,

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there were, in the bed of the river, boulders* of granite, syenite and conglomerate, varieties of rock which I did not observe on the high plain; and I particularly noticed that there were none of the basaltic lava. From this latter fact and from several other circumstances, more especially from the immense quantity of solid matter which must have been removed in the excavation of the deep and broad valley, we may feel sure that the boulders on the intermediate plain and in the bed of the river, are not the wreck of those originally deposited on the high plain. These boulders, therefore, must have been transported subsequently from the Cordillera, and after an interval during which the land was modelled into the form above described. Those on the lowest plain must have been transported within, or not long before, the period of existing shells. I have said that the first erratic block which I met with, was sixty-seven miles from the nearest slope of the Cordillera; I must, however, record the case of one solitary rounded fragment of feldspathic rock lying in the bed of the river, at the distance of 110 miles from the mountains. This fragment was seven feet in circumference, and projected eighteen inches above the surface, with apparently a large part buried beneath it. As its dimensions are not very great, we may speculate on some method of transportal different from that, by which the plain near the mountains was strewed with such innumerable boulders; for instance, of its having been imbedded in a cake of river ice. Its solitary position is, however, a singular fact. I met with erratic boulders nowhere else in Patagonia: Captain King, however, states, in his “Sailing Directions,”2 that the surface of Cape Gregory, a headland of about 800 feet in height, on the northern shore of the Strait of Magellan, is strewed with great fragments of primitive rocks. 2. Tierra del Fuego and the Strait of Magellan The eastern part of Tierra del Fuego is formed of large outliers of the Patagonian |418| formation, fringed by deposits of much more recent origin, the height of which varies from about 100 to 250 feet. These lower, irregular plains have been elevated within the post-pliocene period. They consist of fine-grained, earthy or argillaceous sandstone, in very thin, horizontal, but sometimes inclined laminæ, and often associated with curved layers of gravel. On the borders, however, of the eastern parts of the Strait of Magellan, this fine-grained formation often passes into, and alternates with, great unstratified beds, either of an earthy consistence and whitish colour, or of a dark colour and of a consistence like hardened coarse-grained mud, with the particles not separated according to their size. These beds contain angular and rounded fragments of various kinds of rock, together with great boulders. At Elizabeth Island, within the Strait, there are good sections of this deposit in cliffs 150 feet high, and composed chiefly of whitish earth, with fragments of syenite, greenstone, feldspathic rocks, clay and hornblendic slates and quartz, most of which do not occur, in situ, in the neighbourhood. These fragments are generally arranged without the slightest trace of order,—large and small, angular and rounded being close together; but in *

I may observe, that it can be clearly shown (Journal of Researches, p. 216) that the river itself, although large and rapid, has scarcely any power in transporting fragments even of inconsiderable size.

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1842. On the distribution of the erratic boulders

some parts of the cliff, the mass is divided by beds of stratified shingle, and these are most frequent in the upper part,—a fact which I observed in other places. Few of the fragments much exceed in size a man’s head, but there are numerous large boulders on the beach. In the cliff at Cape Negro, which is close to Elizabeth Island, and is of the same height and of nearly the same nature, I saw a great boulder imbedded. This deposit at Nuestra Señora de Gracia is rather finer grained, and contains fewer fragments; some of which are perfectly rounded, some quite angular; and a single one, of considerable size, is often imbedded by itself in fine-grained and fine-laminated matter. I here, also, observed a boulder at least four feet in diameter, projecting from the face of the cliff. In a neighbouring cliff, a whitish mass fills up hollows in an underlying finer-grained bed. North of Cape Virgins, close outside the mouth of the Strait, the cliffs are between 200 and 300 feet in height; and they consist of an argillaceous sandstone in horizontal laminæ, as fine as roofing-slate, which in several places is interstratified with two or three beds of the coarse nature just described, each stratum being from five feet to twenty thick. These beds often thin out and become curvilinear at each end. The imbedded fragments are of the same nature and shape as before mentioned; and their parent rock cannot be less, and probably is considerably more, than 120 geographical miles distant. In the other cases above described, the distance must be at least sixty miles. The mountains, from which they all probably came, lie west and south-west. The numerous boulders before noticed on the beach at the foot of the cliffs on Elizabeth Island, consist of the same varieties as the smaller imbedded fragments, |419| and are from one to four feet in diameter; the outline being irregularly angular, with only the edges blunted. In the other places above mentioned, and likewise at the base of the mountains on the line of coast extending south to Port Famine, boulders are numerous on the sea-beaches. Although I saw only two in the cliffs, yet as the boulders do not, as far as I was able to observe, occur scattered on the surface of the ground, and as a large area has evidently been denuded, I concluded that most of the blocks were originally enclosed in the deposit, and that after they were washed out, they had been driven onwards by the surf during gales, and collected at the foot of the retreating cliffs. At St. Sebastian’s Bay, however, on the east coast of Tierra del Fuego, this explanation is scarcely applicable, for many gigantic boulders there lie in a protected position at the base of a naked cliff about 200 feet in height, and entirely composed of thin strata of fine-grained sandstone, with a few layers of small, well-rounded pebbles. As it is very improbable that the boulders were ever included in a deposit of this nature, we must suppose that they were originally thrown down either on the surface or in a thin superficial bed, which has subsequently been removed. I may specify, that one of these boulders, composed of syenite and shaped somewhat like a barn, was forty-seven feet in circumference, and projected about five feet above the sand-beach. There were many others half this size, and they all must have travelled at least ninety miles from their parent rock. The position of the boulders in St. Sebastian’s Bay is, in another respect, interesting; for the form of the land clearly shows, that long anterior to the total amount of elevation attested by upraised recent sea shells, a wide channel (indeed, introduced in all the charts before the

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voyage of the Beagle) connected the middle part of the Strait of Magellan with the open sea. During the same period, a very low neck of land near Cape Negro, now strewed with boulders and bordered by cliffs of the unstratified deposit, must have formed a straight channel between the great land-locked bay called Otway Water, and the eastern arm of the Strait of Magellan. Shoal Harbour, which lies in this line, is scattered over with enormous angular fragments of rock, projecting from five to eight feet above the level of the sea, and giving to it a singular appearance. The unstratified beds of hardened mud and whitish earth, containing a few boulders and numerous smaller angular as well as rounded fragments, occur only in the neighbourhood of the Strait of Magellan, and are probably connected in their origin with the existence of an ancient channel which had nearly the same direction with the present one: so also it is evident, that the distribution of the numerous great boulders now lying on the surface (whether or not all were originally imbedded in the unstratified deposit) is likewise connected with the course of formerly existing sea-channels. The currents off Cape Horn set almost constantly from the west, as is known to the cost of |420| all those who have to double it; hence they probably set in a similar direction through the above ancient channels, when more open and less crooked than the Strait of Magellan now is. It is in accordance with this circumstance, that, in the districts just described, and in that which we are immediately to treat of, the boulders and smaller fragments have all travelled from mountains situated to the west. In a space about forty miles broad at the extreme south-eastern part of Tierra del Fuego, including Navarin and several smaller islands, the shores are fringed at about an equal height, by a deposit very closely resembling the unstratified beds in the Strait of Magellan. On the south side of Navarin Island it forms a small plain (the only level land in that part of the country), fronted by a line of cliff several miles in length, and about sixty feet in height. In this cliff there is not a trace of stratification; and the earthy, rather argillaceous mass contains fragments, some angular, but mostly rounded, of all sizes, from mere particles to great boulders, of nearly the same composition as the fragments in the Strait of Magellan. Similar rocks do not occur in situ within sixty miles; and probably some exist only at a considerably greater distance. Within the eastern mouth of the Beagle channel, forming part of the above-mentioned area, the cliffs are higher, and the beds are sometimes regularly interstratified with layers of shingle. I cannot more accurately describe the appearance of the cliffs around Navarin Island, than by the remark which, at the time, I entered in my note-book, “that a vast debacle appeared to have been suddenly arrested in its course.”3 But this explanation always appeared to me, from the width and openness of the channels both to the east and west, and from the proofs of the very gradual elevation of the land in the neighbouring countries, to be encumbered with the greatest difficulty. Hence the origin of these beds, as well as of those in the Strait of Magellan, which, although unstratified, are of submarine formation, remained quite inexplicable to me. This deposit resembles the till of Scotland, the boulder formation of Northern Europe and of the eastern coast of England, in the following respects, which clearly indicate, as Mr. Lyell* has remarked, some peculiar *

Mr. Lyell on the Boulder Formation of East Norfolk. Philosophical Magazine, 1840, p. 348.

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1842. On the distribution of the erratic boulders

origin; first, in the entire absence of stratification in one part of a bed, which in another shows, either throughout its whole thickness or in alternate beds, signs of regular deposition; secondly, in the close juxtaposition of fragments of far-transported rocks, varying in size from minute pebbles to boulders, some being rounded and others angular; and lastly, as I believe, in the frequent occurrence of a capping of gravel. Mr. Lyell, after having examined this kind of deposit (which for briefness I will call by the Scotch term ‘till’) in the several countries above specified, ascribes its origin to the deposition, in a tranquil sea, of mud, sand and blocks, from melting drift-ice; |421| but in the area, near the eastern mouth of the Strait of Magellan, where the finest sediment has been arranged in horizontal laminæ, and the coarse shingle in beds, it appears strange that stratification should be so entirely, and often suddenly, absent in the till alone. The mere dropping of the fragments seems hardly sufficient to explain this; for we have seen that both angular and rounded fragments sometimes occur imbedded in the finest laminated matter. Perhaps the disturbing action of the icebergs when stranded, as suggested by Mr. Lyell, may account for this remarkable deficiency of stratification in the till. I will only further add, that I looked in vain for any marine remains in these till-deposits, and a similar deficiency has been remarked in those of Europe. We must not suppose that their absence can be accounted for by a bottom of this nature being unfavourable to the existence of marine animals, for both in the retired and only partially protected bays of Tierra del Fuego, kelp (Fucus giganteus) grows in a depth of from two to twenty fathoms on the loose round stones, and between the roots of the kelp innumerable creatures live: in the open sea also, where there was no kelp, I found numerous Terebratulæ and other shells, on stones lying in mud. But when we reflect how great a number of icebergs, some charged with foreign matter, but very many more without any, must, on the above theory, have been drifted to the spot while the till was accumulating; and that these icebergs being lifted up and down by the tides, as well as being broken into pieces and many times stranded, would plough up large tracts of the bottom of the sea, part of the difficulty in explaining the absence of marine remains in the till is removed, for we can hardly conceive the existence of any animal on a soft bed of mud and stones, disturbed at intervals with great violence. An interesting description is given by Wrangell* of the fragments of ice off the coast of Siberia, often raised into a vertical position, and which, to use his words, “are driven against each other with dreadful crashes, are pressed downwards, and reappearing again on the surface covered with the torn up green mud, which we had often seen on the highest hummocks.” The particular case thus described happened 100 miles from the main-land, where the water however was only about fifteen fathoms deep: many of the hummocks were about 100 feet high. Wrangell states, that within the line of large hummocks the sea was generally tranquil, and strewed with only small fragments of ice; so that in this case undisturbed strata of gravel or other matter might easily (during the

*

Wrangell’s ‘Voyage to Siberia and the Polar Sea,’ translated by Major Sabine, p. 257.

1842. On the distribution of the erratic boulders

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Fig. 2.

gradual elevation of the land, believed to be there in progress) accumulate over the disturbed beds; and in these latter deposits it is not probable that any organic remains would be enclosed. There are two Sections at Gregory Bay, in the eastern part of the Strait of |422| Magellan, which are worthy of description. The cliffs are composed of the usual blackish indurated till, in some places interstratified with yellowish argillaceous sandstone, including a few large pebbles. In one cliff about twenty-five feet high (Fig. 2, which is traced from an outline made upon the spot), the main part consists of finely laminated yellow mud (B), which, a little further to the right, includes many fragments of rock and loses its laminated character. On the left it alternates with layers of blackish mud (D), which are inclined at an angle of 65°, and at the foot of the cliff form a regular saddle. Many of these layers lose themselves in the yellow sandy mud in the most singular convolutions. In another cliff, Fig. 3. a bed, about eighteen inches thick and thirty feet in length, of fine sandy clay, lying in a coarser sort, dips gently at one end, and at the other is bent back under itself. The subordinate layers in this stratum are curved in basin-, or rather urn-shaped folds about a foot wide, and are placed at nearly equal intervals, so as to resemble some architectural ornament. They cannot always be traced from one basin to the other. The extreme degree of their curvature shows that they were not deposited in so many furrows at the bottom of the sea: it may, perhaps, be conjectured, that during the great and unequal pressure to which the whole mass has been subjected, the finer-grained laminated matter of which these urn-shaped basins consist, yielded more readily, and slided in between the parts exposed to a less force. With respect to the agency by which both sections have been contorted, from the general undisturbed state of the whole country

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1842. On the distribution of the erratic boulders

Fig. 3.

and of the immediately |423| joining beds, and likewise from the peculiarity of the flexures in Fig. 2, I could not at the time persuade myself it was by ordinary violence from below, and no other solution occurred to me. Mr. Lyell* has shown, that in the districts in Europe where the till and boulders occur, most curiously contorted layers are directly superimposed on undisturbed beds, and he suggests as one explanation, the lateral force exerted by stranded icebergs. As we have here also the till and boulders, the forcing up and mingling together of these sedimentary deposits, have, perhaps, been effected by this same agency;† an agency, however, which in most cases appears merely to have prevented the separation of the drifted materials into distinct layers. 3. Island of Chiloe Passing from the extreme southern part of the continent along the west coast, I did not land south of lat. 47°. It was, however, between lat. 49° and 50° that the fragment of granite, described in my Journal,4 was seen floating on an iceberg twenty miles from its parent

* †

Philosophical Magazine, 1840, p. 379: Mr. Lyell on the Boulder Formation, &c., Proceedings, vol. iii. p. 178. [Lyell 1840a.] Capt. W. Graah, in his Expedition to the East Coast of Greenland, states that there is a part of the coast which derives its name of Puisortok from ice “shooting up from the bottom of the sea in such a manner and in such masses, as in many years to make it utterly impassable.” The cause of this singular phænomenon is unknown. Capt. Graah suggests amongst other causes, that these masses may be the remains of icebergs frozen to the bottom; but is it not much more probable that the icebergs were first driven deeply into the soft bed of the sea, and that they did not become disengaged until their whole upper parts had been washed away and their buried sides loosened by the melting of the ice? [Wilhelm August Graah (1793–1863), Danish naval captain and explorer. Graah 1837, pp. 79–80.]

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glacier, and therefore we may feel sure that erratic boulders occur in this space. Between lat. 47° and the southern extremity of |424| Chiloe I landed on several parts of the seaward coast, but did not notice a single boulder: as, however, it is separated from the Cordillera by intervening high land, the absence of erratic blocks might have been expected. At Chiloe I again found transported boulders in vast numbers. This island is a hundred miles long, extending from lat. 41° 460 to 43° 260 ; and it lies parallel to the Cordillera, at the distance of about thirty miles from their base. It consists of mica-slate with two volcanic formations, largely bordered, chiefly on the eastern and northern sides, with horizontally stratified beds of tertiary sandstone and volcanic grit; the sandstone in some places passing into a loosely aggregated conglomerate. On the eastern coast the land is indistinctly modelled into successively rising plains, of which the superficial parts, and the whole thickness of some of the lower plains are composed of stratified shingle. This accumulation, where it caps the tertiary deposits, is evidently of subsequent formation; but I do not pretend to distinguish, in all cases, the shingle beds of more recent origin, from the above-mentioned tertiary conglomerate. The boulders occur in extraordinary numbers on the whole line of the eastern and northern beaches, and likewise to the height of at least 200 feet on the land. I saw a few imbedded in the cliffs of gravel; and as many extensive reefs show that there has been much denudation, I presume that many of the masses were originally included in the gravel. The boulders are likewise very numerous on the islets, which lie close to the eastern coast of Chiloe, and are separated from it by channels, which, although very narrow, vary in depth from 50 to more than 300 feet. In two places where I visited the outer or western coast of Chiloe, I did not see any transported blocks, nor did I during a ride of about thirty miles across the central high land. The boulders consist of several varieties of granite and syenite; those of the latter rock are common on the northern beaches; but all the masses which I noticed thirty miles southward were of granite. Their parent rock probably exists in the Cordillera: an intelligent resident pointed out to me several varieties of syenite and granite at the northern end of the island, which, he assured me, he had seen forming whole mountains in the vicinity of Reloncavi Sound, which is situated in the same latitude: if so, these boulders must have travelled more than forty miles. I saw no granite or syenite in Chiloe, there is certainly none on the northern or on the eastern coast, the whole of which I examined, and I feel pretty sure none occurs in the northern part of the island; but it is not improbable that some of the western heights, which were estimated at 3000 feet, may be formed of granite. If any of the boulders have come from the heights of Chiloe, they have crossed a broad and level border of the tertiary deposits; but it is far more probable that all came from the Cordillera. The larger boulders were quite angular, and resembled fragments at the foot of a steep mountain. One mass of granite at Chacao |425| was a rectangular oblong, measuring fifteen feet by eleven, and nine feet high: another on the north shore of Lemuy islet was pentagonal, quite angular, and eleven feet on each side; it projected about twelve feet above the sand, with one point sixteen feet high: this fragment of rock almost equals the larger blocks on the Jura. There were very many others from two-thirds to a quarter of these dimensions. The boulders amongst the islets were in fewer numbers and more rounded than those on the open parts of the eastern

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coast; but I believe this remark applies only to the smaller masses, which may have been rounded subsequently to their first transportal. The position of the boulders at the extreme northern point of Chiloe, where a headland about 250 feet high is joined to Lacuy peninsula by a quite low neck, deserves further notice. This headland, from the similarity of its composition, height and stratification, must once have been continuous with the coast of Chiloe. The ancient currents of the sea, which almost insulated the headland, deposited on its inland side, and on the opposite coast, beds of regularly stratified shingle. Some boulders were enclosed in these strata, and many very large angular ones of syenite were lying both on the low sandy isthmus, and on its sides at a height of 150 feet; and transported blocks were certainly far more numerous here than in any other part of the surrounding country. Anterior to the elevation, which has taken place within the post-pliocene period, the headland must have been an island, and the present low neck of land the bottom of a channel, open to the rush of tidal waters which flowed between Chiloe and the mainland of America. We thus see, even more clearly than in Tierra del Fuego, that there is an evident relationship between the distribution of the boulders, and the lines of either anciently or now existing straits. From this consideration, I was at first surprised at the occurrence of numerous blocks in the tortuous channels, between the islets and eastern coast of Chiloe; but I overlooked the fact, that, anterior to the modern period of elevation just alluded to, the middle part of Chiloe, in the line of the Lake Cucao, must, from its lowness, have been breached by a transverse channel. Had the space between Chiloe and the Cordillera been converted into land, the boulders, in their position with respect to their probable parent rocks, in their size and angular shape, would have resembled those on the Jura; the blocks of granite now lying between the islets, being the representatives of those which, M. Agassiz has lately shown, occur in the interior valleys of that range.5 Of the few imbedded boulders which I saw, most were in the stratified gravel; but I find in my note-book two sections obtained in the southern half of the island, and described as consisting of hardened mud, including angular as well as rounded fragments of fartransported rocks, and in one instance a boulder.6 These deposits |426| evidently are similar to those called ‘till,’ and I feel nearly sure that they were unstratified; but not being then aware of their interest, I merely compared them to the deposits in eastern Tierra del Fuego, and I here record only what I at the time wrote down. On the inner side of one of the Chonos Islands, a little south of Chiloe, in lat. 43° 500 , there are cliffs about 300 feet high, which I likewise only partially described, as formed of blackish hardened mud with scattered pebbles of various sizes, some well rounded, some but slightly: as I especially noted that the gravel in the upper part of the cliff was stratified, I presume there was little arrangement in the lower. In one layer of loose sand at the base of this cliff, where the hardened mud passed into laminated sandy clay, I found a quantity of comminuted marine shells with a fresh aspect, but too much broken to be characterized. At Chiloe also, in one place where a mass of till passed into fine-grained, laminated beds, I found two or three fragments of a Cytheræa. I must, however, observe, that the absence of marine remains in these beds of till, is much less remarkable than in those of Great Britain, because the surrounding stratified formations here contain but very few shells.

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Indeed in Chiloe I found none, excepting where the sandstone contained calcareous concretions. With respect to the age of the boulder formation of Chiloe, and I may add, of Tierra del Fuego, I have no precise information. The whole east coast of the island has been elevated certainly from twenty to forty feet, and probably much more, within the post-pliocene period; for on the peninsula of Lacuy (near where I have described the boulders on the low neck) I found, at a height of 350 feet, a great bed of existing shells, out of which forest trees were growing. I have stated, that in eastern Tierra del Fuego the boulder formation has also been elevated within this same period. Without we suppose that the boulders were deposited in a deep sea, which does not appear very probable from the nature and stratification of the accompanying deposits, or without we suppose great oscillations of level of the land, the boulder formation must have been accumulated since the commencement of the post-pliocene æra, or but little before it. From indirect evidence, also, and therefore to be received with limited confidence, I came to the same conclusion with regard to the boulders on the lower plain at Santa Cruz. It is worthy of notice, that geologists have referred the dispersal of the boulders which lie scattered over the temperate parts of the northern hemisphere to this period. I have stated in my Journal, that northward of Chiloe (lat. 41° 470 ) I met with no fragments of far-transported rock which can be classed with the erratic boulders just described;—their great size, frequent angularity, and complete separation by wide valleys or arms of the sea from their parent source, being taken as their distinctive characters: I had opportunities of observing them in the country around Valdivia, Concepcion, and many parts of central and northern Chile. In these |427| same districts I did not meet with any beds of till. North of the Strait of Magellan, on the sea-shores of Patagonia* and La Plata, neither boulders nor beds of till occur in the same latitudes, under which both are present on the Pacific. With respect to the erratic masses, we may infer from what has been shown in the ascent of the Santa Cruz, that their absence is owing to the wide space separating the shore of the Atlantic from the Cordillera. In my Journal I have endeavoured to show in detail, that, in the northern parts both of the Old and New World, and in the southern parts of South America, the dispersal of boulders has been limited, in approaching the tropics, to nearly the same latitudes, and that no true blocks of this description have been observed in the inter-tropical regions;† and we may now be permitted to suspect that beds of ‘till’ will be found to be confined to the same parallels of latitude as the boulders. *

†

I may here mention, that on East Falkland Island, although situated in the same latitude with Tierra del Fuego, and lying only 250 miles eastward of it, and with mountains above 2000 feet in height, I did not observe any erratic boulders. As it may occur to some geologists that the island may have received its chief elevation, subsequently to the period of the dispersal of the boulders on the main-land, I will observe, that the facts are directly opposed to such a view, for I could not find any elevated marine shells on this island; whereas I did not land on a single point of the coast of Patagonia, or of eastern Tierra del Fuego, without meeting with them. In my Journal (p. 289, and Appendix, p. 615), where I have considered the apparent exceptions to this statement, I accidentally omitted one case. Near Rio de Janeiro I met some large-sized boulders of greenstone, containing iron pyrites; they were perfectly rounded, and therefore wanted that character of angularity, which, though far from being always a concomitant, may, where it is present, be considered as eminently distinctive. I could not see the greenstone in situ in the immediate neighbourhood, but the extreme rankness of the vegetation quite precluded accurate investigation. Mr. Caldcleugh (Travels, vol. ii. p. 195) observed greenstone boulders on the road to Villa Rica, and Spix (Travels, Eng. Transl. vol. i. p. 272) [Spix 1824.] observed others on the road to Santa Cruz. Mr. Fox, Minister Plenipotentiary at Rio de Janeiro, informed me that he found similar blocks on the islands of St. Sebastian and St. Catherine, and at Port Alegre on the southern coast of Brazil. [Henry Stephen Fox (1791–1846), British

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4. Remarks on the Glaciers of Tierra del Fuego, and on the Transportal of Boulders In the remainder of this paper I will make a few remarks on the glaciers of Tierra del Fuego, and on the means of transportal of the boulders. I had no opportunity of landing on any glacier, but we passed in the Beagle and Magdalen channels within two miles of several. The mountains were covered with snow, and the glaciers formed many short arms, which descended to the beach, and terminated in |428| low perpendicular cliffs of ice. The surface of these glaciers, even to a considerable height on the mountains, was of a bright azure colour and perfectly clean, as were the floating fragments. This is what might have been expected, from the shortness of the glaciers, from their not being bordered by precipices, and from their not being formed by the junction of two or more smaller streams of ice. Although the chief characteristic of the climate of the southern parts of South America seems to be its equability, yet the glaciers cannot descend very slowly, for large masses are continually breaking from the cliffs of ice. We were witnesses of one fall in the Beagle channel; and the water was strewed with smaller pieces: Capt. King* mentions several bays and channels in Tierra del Fuego almost choked up with them; Mr. Bynoe† informed me that as many as fifty icebergs were seen together in Sir G. Eyre’s Sound: behind the peninsula of Tres Montes, in a latitude corresponding to that of the lake of Geneva, some Spanish missionaries,‡ in an account of their voyage, describe an arm of the sea as crowded with icebergs of all sizes. Some of the fragments of ice which are thus detached are of immense size: Mr. Kirke§ met with one in an inland creek, situated in the corresponding latitude as Paris, which was estimated at forty-two feet in height, and was aground, where bottom could not be obtained with a line of 126 feet. This mass was therefore at least 168 feet in height, equal to a lofty church: how violently must the tranquil waters of the retired creek have been agitated when it fell! Capt. King, describing another case,** compares the crash to a broadside reverberating through these lonely regions. In the Beagle channel the insignificant fall which we witnessed, caused a wave that nearly destroyed our boats, though hauled up on the shore, and at the distance of half a mile from the cliff of ice.7 These waves seem to displace and drive before them the fragments of rock lying on the beach. Although the glaciers I saw were quite clean, many of the icebergs described by Mr. Kirke in Sir G. Eyre’s Sound were dark coloured, and on the surface of one, several blocks of granite and serpentine were found. The glaciers in the Beagle channel were generally bordered by a tongue of land, formed of huge fragments of rock, and many boulders were strewed on the neighbouring shores. The only glacier which I approached closely, descended to the head of a creek, formed on

* † ‡ §

diplomat, Minister Plenipotentiary, Buenos Aires, 1831–32; Rio de Janeiro, 1833–36.] Nevertheless, it is not improbable that in all these cases the parent rock was not far distant. I found two greenstone dykes near Rio de Janeiro: Von Eschwege mentions others, and Mr. Fox observed one on St. Sebastian. [Wilhelm Ludwig von Eschwege (1777–1855), German miner, geologist and geographer. Eschwege 1832.] Besides many obvious means of transportal to moderate distances of large fragments of rock, now that geologists generally admit that most countries have undergone slow oscillations of level, we must not overlook the power which the surf during gales would have, on an exposed and gently inclined surface, of driving onwards blocks of rock from the top of one line of beach to that of another, as the sea gradually encroached on the land. Voyages of the Adventure and Beagle, vol. i. pp. 56, 58, 140, 258. The Author’s Journal of Researches, p. 283. [Benjamin Bynoe (1803–65), Assistant Surgeon on the Beagle.] Ibid., Appendix, p. 613. [Agueros 1791, p. 227.] ** Voyages of the Adventure and Beagle, vol. i. p. 337. [J. Kirke mate on the Beagle.] Ibid., vol. i. p. 140.

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one side by a wall of mica-slate, and on the other by a broad promontory, about fifty or sixty feet high, and apparently composed entirely of enormous fragments, chiefly of granite. One of these was ninety feet in circumference, and projected six feet above the sand. This promontory, which originally no doubt was a lateral moraine, projects nearly half a mile beyond the |429| extremity of the glacier, and is in parts covered by old trees: hence we must infer, that the glacier formerly extended considerably further than it now does. It would be useless even to allude to the difficulties which affect every theory of the transportal of erratic boulders, excepting that by the agency of ice; but after the remarkable discoveries of Venetz, Charpentier, Agassiz, and others, of the great extension in Europe of moraines formed by ancient glaciers, it is necessary to observe, that neither the ‘till’ beds of eastern Tierra del Fuego, which pass into and are regularly interstratified with a great formation of horizontally laminated sandstone, containing marine remains; nor the stratified gravel and till, which form low plains on the shores of Chiloe, and cap in regular beds the tertiary strata, can have been produced like ordinary moraines; and, therefore, that the imbedded boulders cannot have been propelled by the glaciers themselves. I am led to the same conclusion with respect to the till of southern Tierra del Fuego, which forms a level plain and a fringe around several islands, and which in one part passes into a regularly stratified deposit. The boulders on the lower levels at the head of the Santa Cruz river are strewed on land, which certainly has been modelled by the action of the sea. Those on the 1400 feet plain are sixty-seven miles from the Cordillera, of which the highest pinnacle is only 6400 feet, and the general range considerably lower; this little inclination of the surface, with the absence of mounds or ridges on it, and the angularity of the fragments, are opposed to the notion that the blocks have been pushed to this great distance by glaciers. Hence I conclude, that in the two first-mentioned districts it is quite certain, and in the three latter highly probable, that the boulders were transported by floating ice. The fact of many of the blocks on the northern end of Chiloe being different from those thirty miles southward, where there must anciently have been a channel across the island, is not opposed to the foregoing conclusion: for the tidal currents must have drained, according to the number and position of the seaward channels, determinate spaces of the area between Chiloe and the Cordillera; and according to the situation of the spot whence the iceberg with its cargo of rock was first launched, so would it be swept towards one or the other channel. The varying winds, no doubt, would partly influence the course of icebergs, but, from their floating very deeply, the currents would act far more powerfully on them. Nor is the circumstance of the boulders on the high and low plain of Santa Cruz being of different kinds of rock any difficulty; for after the change of level in the land, necessary to account for the existence of the lower plains, we might have anticipated that some of the glaciers which formerly debouched on the coast would cease doing so; and that rocks hitherto submerged beneath the sea would become exposed, and their fragments falling on the glaciers would be transported with the icebergs. |430| It appears that masses of floating ice, by which fragments of rock are conveyed, are produced in two ways, and under circumstances considerably different although often acting together, namely, by the breaking off of icebergs from glaciers descending into the sea, and

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by the actual freezing of the surface of the sea or its tributary streams. Great boulders can be included in ice by this latter means only (with rare exceptions) where the winter is extremely cold, as in the Gulf of Bothnia8 and on the shores of North America. A large proportion of the fragments thus enclosed will generally have been exposed to the wearing influences of the sea-beach; and from the ice being in a sheet, they will be liable to be repeatedly stranded in shallow places, and thus to become still more worn. The other method of transportal, namely, by the descent of glaciers to the sea-level, and the production of icebergs, is far from necessarily requiring an extremely cold winter; for the low descent of glaciers seems to depend (other circumstances being alike) in a much greater degree on the summer not being hot enough to melt the ice and snow, than on the winter being very cold. Hence, as I have endeavoured to show in my Journal (chap. xiii.), glaciers in South America descend to the sea from mountains not very lofty, and in latitudes extraordinarily low compared with those in Europe under which the same phænomenon takes place; and yet, the vegetable and animal productions of this kind of climate have, in some degree, an inter-tropical character. M. Agassiz has shown that blocks of rock are not imbedded in the ice of the Swiss glaciers, except high up near their sources, and that those numerous masses which lie on the surface, from not being exposed to much abrasion, remain angular: hence only loose angular blocks of rock (as was the case with those on the floating ice in Sir G. Eyre’s Sound) can be transported by icebergs, detached from the glaciers of temperate countries. And to effect this, the icebergs must be floated off perpendicularly and in large masses, for otherwise the loose fragments would be at once hurled into the sea. These remarks do not necessarily apply to icebergs formed under a polar climate, for if a glacier in its descent, reached the sea before the fragments of rock which had fallen on the soft snow had come to the surface, icebergs would be produced with imbedded fragments of rock: I have described in the ‘Geographical Journal’* the case of one huge fragment thus circumstanced, seen drifting far from land in the Antarctic Ocean.† As one of the above two methods of conveying erratic boulders, namely, that by icebergs from glaciers, is now in action on the South American shores, we are naturally |431| led to conclude, that this was the chief agent in the enormous amount of transportal formerly effected over a more extended area. It would indeed require the strongest evidence to make one believe that the surface of the sea, or even of rivers, between lat. 41° and 42°, had ever been frozen thickly enough to enclose the huge masses of rock which we now find stranded on the island of Chiloe. The angularity of their forms at this latter place and at Santa Cruz, accords with their transportal by icebergs; but it is not improbable that the other agency, namely, the freezing of the sea, may formerly have been instrumental in Tierra del Fuego, and especially in the southern parts of that country, where the boulders frequently show signs of attrition, as if they had been worn on a sea-beach. In endeavouring, therefore, to determine, in any country where boulders occur, the nature of the climate during their dispersal, we should attend * †

Geographical Journal, 1839, p. 528. [Darwin 1839, F1652 (p. 95).] Dr. Merten’s observed many fragments of rock imbedded only just above the level of the sea in the lateraal wall of the glaciers at Spitzbergen, but he never saw any in the cliffs of ice facing the sea. – Edinburgh New Phil. Journal, 1841, pp. 173 and 176. [Charles Martins (1806–89), French physician and traveller who visited Spitzbergen in the Recherche in 1838. His name was misspelled by the New Edinburgh Philosophical Journal, and differently by CD, Martins 1841.]

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not only to the character of the contemporaneous organic productions, but likewise to the shape of the fragments and to their position; for these circumstances would aid us in discovering whether they had been imbedded in sheet-ice, or carried on the surface of deeply-floating icebergs.

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See the abstract of this paper in Darwin 1841, F1657 (p. 128). King 1832. This passage has not been traced. Journal of researches, p. 282. Agassiz 1838. See Chancellor and van Wyhe eds. Port Desire notebook, in Beagle notebooks. See Narrative 2: 217. The north part of the Baltic Sea, between Sweden and Finland.

1842. Report of a Committee appointed “to consider the rules by which the nomenclature of Zoology may be established on a uniform and permanent basis.” London: John Murray. F1661a1

1

This was the first appearance of the Strickland, or Stricklandian, Code or Rules as Hugh Edwin Strickland (1811–53), geologist and zoologist, was the reporter for the committee, co-signed by ‘C. Darwin’ 27 June 1842. It is here omitted for lack of space.

1843. Remarks on the preceding paper in a letter from Charles Darwin, Esq. to Mr Maclaren. Edinburgh New Philosophical Journal 34 (January): 47–50. F1662 Down near Broomley, Kent. Dear Sir,—I have been so much pleased with the very clear, and, at the same time, in many points quite original manner in which you have stated and explained my views, that I cannot refrain from troubling you with my thanks.1 Your third objection appears to me much the most, indeed the only, formidable one, which has hitherto occurred to me.2 I fear I shall be tempted to reply to it at great length, but perhaps sometime you will find leisure to read my attempted vindication. With respect to the first objection,3 I can hardly admit that we know enough of the laws of elevation and subsidence to argue against the theory, because the areas of different movements are not more distinct. Some have been startled at my view on directly the reverse grounds to your objection, viz. that, according to their notions of probability, the areas of the same movements were too large and uniform. With respect to your second objection,4 all those who believe that exceedingly slow and gradual elevations are the order of nature, must admit a great amount of contemporaneous denudation, which would tend to annihilate the characteristic form of the fringing-reefs during their upheaval, and leave merely a coating on the upraised land of coral-rock either thicker or thinner, according to the original thickness, rate of growth of the reef at each successive level, and the rate of elevation; indeed I am surprised that there exists even one case, viz. at Mauritius, where the peculiar moat-like structure of a mere fringing-reef has been partially preserved on dry land. Your third criticism strikes me as a very weighty and perplexing one. |48| It had passed through my head, but I had not considered it with nearly the attention it deserved, otherwise

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I assuredly would have noticed it in my volume.5 I had always intended to examine the limestone formations of England for comparison, but was prevented by bad health; I was, however, led away from the subject, and baffled when I consulted published accounts, for the limestones all appeared to be uniformly spread out, and most, if not all of them, to be associated with layers of earthy matter, whereas a formation of the nature of a group of atolls, would consist of separate large patches of calcareous rock, which would be quite pure.—I was thus led from the subject, and did not reflect on their want of thickness. The want of thickness, however, in any limestone formation, until it be first shewn to be analogous in structure, form, and composition, to a barrier-reef, an atoll or group of atolls, evidently cannot be brought forward as any argument against the theory of the long-continued subsidence of reefs of these classes. During the elevation of all reefs in open seas, I think there can be no doubt (as is dwelt on at p. 117, 3d.6 vol.) that a considerable thickness of the exterior would be denuded, and the only parts preserved would be those which had accumulated in lagoons or lagoon-channels; these would be chiefly sedimentary, and in some cases might contain (p. 117) scarcely any coral; within barrier-reefs such beds would often be associated with much earthy sediment. Mr Lyell, in a note just received, in which he alludes to your criticisms, speaks of the limestones of the Alps and Pyrenees, as being of enormous thickness, namely, about 4000 feet. I do not know what their composition is, but I have no doubt that the strata now accumulating within the barrier-reef of Australia and New Caledonia, are chiefly formed of horizontal layers of calcareous sediment and not of coral. I suspect that denudation has acted on a far grander scale than in merely peeling the outsides of upraised reefs. My theory leads me to infer that the areas, where groups of atolls and barrier-reefs stand, have subsided to a great amount and over a wide space. Now it appears to me probable that a subterranean change, producing a directly opposite movement, namely, a great and widely extended elevation, would be extremely slow, and would be interrupted by long periods of rest, and perhaps of oscillation of level. When I think of the denudation along the fault, which goes across the northern carboniferous counties of England, where 1000 feet of strata have been smoothed away; when I think how commonly volcanic islands, formed of very hard rock, are eaten back in cliffs from 100 or 200 to 800 or 1000 feet in height, I hardly see where we can stop, with respect to the probable limits of erosion on the comparatively soft, generally cavernous, tabular, though wide, masses of coral rock, standing exposed in great oceans during very slow changes of level. Most of the atolls which have been raised a few hundred feet are mere wrecks, and at the Friendly Archipelago where there are upraised atolls, there are large irregular reefs, also, which I have always thought were probably the basal vestiges of worn down atolls. Many submerged reefs, which may have had this same origin, occur outside the line of elevation of the Salomon and New Hebrides archipelagoes. The great steepness of the shores of upraised reefs (p. 65. Ehrenberg7 quoted, and p. 51.) would probably be unfavourable to the growth of new |49| reefs, and therefore to the protection afforded by them. I can conceive it very possible, that should, at some period, as far in futurity as the secondary rocks are in the past, the bed of the Pacific, with its atolls and barrier reefs, be raised in reefs, by an elevation of some thousand feet, and be converted into a continent, that scarcely any, or none of the

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existing reefs would be preserved; but only widely spread beds of calcareous matter derived from their wear and tear. As a corollary from this, I suspect that the reefs of the secondary periods (if any, as is probable, existed), have been ground into sand, and no longer exist. This notion will certainly at first appear preposterous; its only justification lies in the probability of upward movements after long periods of subsidence, being exceedingly slow and often interrupted by pauses of rest, and perhaps of oscillations of land, during all which the soft coral rock would be exposed to the action of waves never at rest. This notion, preposterous as it will probably appear, would not have occurred to me, had I not several times, from independent reasons, been driven to the conclusion, that a formation to be preserved to a very distant æra (or which probably is the same thing, to be elevated to a great height from its original level over a wide area) must be of great extent, and must be covered by a great thickness of superincumbent matter in order to escape the chances of denudation. I have come to this conclusion chiefly from considering the character of the deposits of the long series of formations piled one upon another, in Europe, with evidence of land near many of them. I can explain my meaning more clearly by looking to the future; it scarcely seems probable, judging from what I see of the ancient parts of the crust of the earth, that any of the numerous sub-littoral formations (i. e. deposits formed along and near shores, and not of great width or breadth), now accumulating on most parts of the shores of Europe (and indeed of the whole world), although, no doubt, many of them must be of considerable thickness, will be preserved to a period as far in the future, as the lias or chalk are in the past, but that only those deposits of the present day will be preserved which are accumulating over a wide area, and which shall hereafter chance to be protected by successive thick deposits. I should think that most of the sublittoral deposits of the present day will suffer, what I conclude the sublittoral formations of the secondary æras have generally suffered, namely, denudation. Now, barrier and atoll coral reefs, though, according to my theory, of great thickness, are, in the above sense, not widely extended; and hence I conclude they will suffer, as I suspect ancient coral reefs have suffered—the same fate with sublittoral deposits. With respect to the vertical amount of subsidence, requisite by my theory to have produced the spaces coloured blue on the map, more facts regarding the average heights of islands and tracts of land are wanted than all those, even if perfectly known, which this one world of ours would afford; for the question of the probable amount, or, which is the same thing, the probable thickness of the coral-reef, resolves itself into this,—What is the ordinary height of tracts of land, or groups of islands |50| of the size of the existing groups of atolls (excepting as many of the highest islands or mountains in such groups, as there usually occur of “encircled islands” in groups of atolls)? and likewise what is the ordinary height of the single scattered islands between such groups of islands?—subsidence sufficient to bury all these islands (with the above exception) my theory absolutely requires, but no more. In my volume, I rather vaguely concluded that the atolls, which are studded in so marvellous a manner over wide spaces of ocean, marked the spots where the mountains of a great continent lay buried, instead of merely separate tracts of land or mountainous islands; and I was thus led to speak somewhat more strongly than warranted, of the probable vertical amount of subsidence in the areas in question.

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Mr Lyell in the note alluded to, thinks we are much too ignorant of intra-tropical geology (and ignorant enough we certainly are) to affirm that calcareous rocks of the supposed thickness of coral reefs, do not occur. I am inclined to lay considerable stress on this. I do not expect the foregoing view will appear at all satisfactory to any one besides myself,— I believe, however, there is more in it than mere special pleading. The case, undoubtedly, is very perplexing; but I have the confidence to think, that the theory explains so well many facts, that I shall hold fast by it, in the face of two or three puzzles, even as good ones as your third objection. Believe me, my Dear Sir, yours very truly, Charles Darwin.

1 2 3 4 5 6 7

Maclaren had reviewed Coral reefs in the Scotsman of 29 October and 9 November 1842. A slightly abridged version appeared as Maclaren 1843 followed by this letter. (DO) See CCD2: 331; 341. Maclaren argued (p. 47) that if coral reefs thousands of feet deep exist under the sea, some should be found now elevated on dry land, yet none even 500 feet thick were known. Maclaren argued (p. 46) that there were many apparent exceptions to CD’s generalizations about areas of subsidence and elevation. Maclaren objected (p. 46) that in areas of elevation, more transitional stages from fringing reefs to coral rock on dry land should exist than were known. Coral reefs. Probably a misprint of ‘my vol’ viz. Coral reefs. Christian Gottfried Ehrenberg (1795–1876), German zoologist, comparative anatomist and microscopist. Ehrenberg 1834.

1843. Double flowers—their origin. Gardeners’ Chronicle no. 36 (9 September): 628. F16631 The inclosed specimens appear to me curious, as in some degree connected with the origin of double flowers. They consist of plants of the Gentiana amarella,2 found in a wild state, covered with abortive buds, or rather minute double flowers. Each head consists of innumerable small petal-like purplish scales, having in their centre a tuft of still smaller green scales. A plant covered with these little heads not infrequently bears, especially near the top of the stem, one or two more perfect flowers. By examining these, a series can be shown, by which the stamens are seen to become deformed, and gradually to pass into small petals and scales. The pistil also can be traced, becoming more and more foliaceous. The change in the pistil has been effected in several flowers, whilst the stamens have remained nearly perfect. In the same manner I have observed in double Violets and some other garden flowers, that the pistil, contrary to the general rule, is metamorphosed before the stamens. In other semi-perfect flowers of the Gentiana, the divisions of the corolla and the number of the stamens, with their filaments flattened, are increased; in others, besides the five ordinary stamens, in an imperfect state, the divisions of the corolla are partially converted into stamen-like bodies: if this conversion had been effected, the flower would have become apetalous. In a Bladder-nut (Staphylea) growing in a shady wood, I last summer noticed a similar fact, namely, that the petals showed a tendency to form additional stamens. The

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plants of the Gentiana bearing the little tufts are generally, but not always, dwarfer than the perfect plants; their leaves are less pointed, and the entire plant is much less symmetrical. The much greater number of the imperfect flowers on one plant than are ever produced of the perfect, shows, I presume, that the metamorphic change must be determined early in the plant’s life. Except in their small size, less beauty, and in the occasional presence on the same stem of flowers in different stages of monstrosity, these purple tufts seem to be essentially similar in their nature to the double flowers of Horticulturists. The plants of the Gentiana in both states grow mingled together on a very hard, dry, bare chalk bank; but those with the abortive flowers grow on rather the barest spots, where it was surprising that anything could grow. You state in your “Theory of Horticulture,”3 that the origin of double flowers is not well understood. Some have attributed it to excess of food; but the dry chalk bank surely was not too rich a soil; and I may mention that late last autumn, I found on an adjoining field of wretchedly sterile clay, great numbers of the Ranunculus repens,4 producing semi-double flowers, some having three, some additional rows of petals. The partial or entire sterility of double flowers is generally attributed to their doubleness; but is not this putting the effect before the cause? It is well known that plants (and indeed animals, as I could show by a series of facts) when placed out of their natural conditions, become, often from apparently slight and unintelligible causes, sterile. How many American plants fail in producing pollen in this country! the anthers of the Persian and Chinese Lilacs, as I observed this summer, are as destitute of good pollen as if they had been hybrids. Other plants produce good pollen, but are defective, as it appears, in their ovules, as their germen never swells. Linnæus has remarked that most Alpine plants, when cultivated in the lowlands, are rendered quite sterile. In most of these cases, we see that sterility is compatable with long life and health. Is it, then, too bold a theory to suppose that all double flowers are first rendered by some change in their natural condition, to a certain degree, sterile; and that their vessels being charged with organizable matter in excess, (which would be greatly formed by high cultivation,) it is converted into petals—the organs which are nearest in their morphological nature and position to those whose functions are checked? Is there any shadow of truth in this theory, or is it an abortive one, as are the buds of the Gentiana?—C. Darwin. (We can only say that this is at least as reasonable an hypothesis as any that we have seen; but the greater frequency of double flowers in gardens where soil is rich, than in fields where it is poor, offers some difficulty in the way of Mr. Darwin’s speculation.) P.S.—I also send a curious Cabbage-leaf, grown into the form of a perfect funnel, like the fold of paper into which grocers put sugar. It was borne on a long footstalk from the centre of an old stalk, from which a Cabbage had been cut this summer. I remember that De Candolle describes pitchers at the end of the leaves of some Cabbages, which he compares to those of the Nepenthes.5 Is this leaf something of the same kind? (Yes.) 1

This letter reveals CD’s interest in ‘unity of type’, which was associated with the ‘science of morphology’, proposed by J. W. von Goethe. It was generally accepted in taxonomy in an idealistic Platonic sense. Yet if understood in a genealogical sense it was relevant to the theory of common descent. See Foundations, p. 74. See CCD2: 383.

1844. Observations on the structure and propagation of the genus Sagitta 2 3 4 5

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Autumn Gentian. John Lindley (1799–1865), botanist, professor of botany University College London 1829–60. He was horticultural editor of the Gardeners’ Chronicle from 1841. CD refers to Lindley 1840. Creeping Buttercup. Augustin Pyramus de Candolle (1778–1841), Swiss botanist. CD refers to Candolle 1839–40, 1: 272.

1844. Observations on the structure and propagation of the genus Sagitta. By Charles Darwin, F.R.S., V.P.G.S. Annals and Magazine of Natural History, including zoology, botany, and geology 13, no. 81 (January): 1–6. F16641 The species of this genus are remarkable from the simplicity of their structure, the obscurity of their affinities, and from abounding in infinite numbers over the intra-tropical and temperate seas. The genus was founded by M. M. Quoy and Gaimard;* three species have been figured and described by M. A. d’Orbigny, and lately Prof. E. Forbes has added a species to the British fauna, and has given many particulars regarding the structure of the genus. Scarcely any pelagic animal is more abundant: I found it in lat. 21° N. in the Atlantic, and again off the coast of Brazil in 18° S.; between latitudes 37° and 40° S., the sea, especially during the night, swarmed with them. They generally appear to swim near the surface; but in the Pacific, off the coast of Chile, I obtained specimens from a depth of four feet. They are not confined exclusively to the open ocean, as supposed by M. d’Orbigny; for near the shore of Patagonia, where the water was only ten fathoms in depth, they were very numerous. All the individuals which I caught had two pair of lateral fins, |2| but I do not suppose that they all belong to the same species: those obtained in lat. 37° to 40° S. appear certainly to be the S. exaptera of D’Orbigny; and the few following observations, which relate chiefly to their propagation, apply, when not otherwise stated, to this species. M. d’Orbigny and Prof. Forbes have provisionally placed this genus amongst the nucleo-branch mollusca; but the evidence is hardly conclusive. Head.—The linear-lanceolate head, which is of a transparent, gelatinous and adhesive texture, is separated from the body by a distinct neck. The head when not in action is slightly flattened and of a truncate-conical shape; when in action its basal part assumes a semilunar or horse-shoe form, in the concavity of which lies the longitudinally-folded mouth. On each arm of the fleshy horse-shoe, a comb, formed of eight strong, curved, slightly hooked claws or teeth, is attached. The animal when lively is constantly clasping these bristle-like teeth together, over its mouth; when clasped together, and the head in a state of inaction, they appear to be situated much nearer to the mouth than when their fleshy bases are expanded in action. The middle teeth are the longest; besides their clasping action and the power of

*

Annales des Sciences Naturelles, tom. x. p. 232. [Jean René Constant Quoy (1790–1869) and Joseph Paul Gaimard (1796–1858), French naval surgeons and naturalists. Quoy and Gaimard 1827.] M. d’Orbigny’s observations are given in his grand work (Mollusques, p. 140). [Alcide Charles Victor Marie Dessalines d’Orbigny (1802–57), French naturalist and palaeontologist who travelled throughout South America 1826–34. Orbigny [1834]–47, vol. 5, part 3 (1843): 139–144 and plate 10.] Prof. E. Forbes four years since made his first communication on this genus before the Wernerian Society, and a second one at the Meeting of the British Association for the present year. [Edward Forbes (1815–54), zoologist, botanist and palaeontologist. Forbes 1843.]

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1844. Observations on the structure and propagation of the genus Sagitta

movement in their fleshy bases, each separate tooth can move itself laterally further from or nearer to the adjoining ones. The mouth opens on the oblique surface of a part projecting up, between the two fleshy arms. Close to the mouth there are two other rows of exceedingly minute teeth, which have not been noticed by other observers, and which I discovered only with a lens of high power. These two rows of little teeth project inwards and transversely to the two great upright combs of teeth; so that when these latter are clasped over the mouth the minute teeth cross them, thus effectually preventing any object from escaping which might be caught by the longer curved teeth. I could not see any vestige of eyes or of tentacula. Locomotive organs.—The animal moves quickly by starts, bending its body. The two pair of lateral fins and that on the tail lie in the same horizontal plane: viewed with a lens of small power they appear formed of a delicate membrane, but under a lens of 1/20th of an inch focal distance they appear to consist of excessively fine transparent rays, touching each other, like the barbs of a feather, but not, as it appeared to me, actually united by a membrane. The tail, besides being used as a locomotive organ, serves as a means of attachment; for the animal when placed in a basin of water sometimes adhered by its tail so firmly to the smooth sides, that it could not be detached by a considerable agitation of the water. Out of the innumerable specimens which I procured, I never saw one fastened by its teeth to the ova |3| of pelagic animals, or to other bodies, as M. d’Orbigny has observed in some of his species. Internal viscera.—Within the body, in the same plane with the longitudinally folded mouth, there is a flattened tube or cavity, which in the specimens obtained in lat. 18° S. I observed had the power of contracting and enlarging itself in different parts, and within it there was a distinct peristaltic movement. Within this cavity in the S. exaptera I could clearly discern in the posterior half of the body a delicate vessel, which I presume is the intestine, for it appeared to terminate on one side of the body at the base of the tail. I could discover no vestige of a nucleus, of branchiæ, of a liver, or of a heart. In some exceedingly young specimens, however, just liberated from the egg, there was a distinct pulsating organ (as will hereafter be mentioned) in the anterior part of the body. Propagation.—The state of the reproductive system varies much in animals caught at the same time. Taking a specimen with this system in a high state of development, the tail, or the tapering part of the body into which the intestinal tube does not penetrate, is seen to be longitudinally divided by an exceedingly delicate partition, and to be filled with a pulpy finely-granular matter. The column of matter on each side of the central division also appears (but whether really so I do not know) to be divided, making altogether four columns, as is shown in the diagram. The whole of this matter is in a state of steady and regular circulation, something like that of the fluid in the stems of the Chara.2 The matter flowed upwards in the two outer columns, and downwards towards the point of the tail in the two middle columns. The circulation in the up-flowing columns was most vigorous on their outer sides; and in the down-flowing columns on their insides, that is, on each side of the central partition: this would be accounted for, if we might suppose that the two surfaces of the central partition were covered with cilia, vibrating in a direction opposite to that in which other cilia situated on the inside of the membrane forming the tail were also vibrating. The stationary condition of the granular matter between the two streams, travelling in opposite

1844. Observations on the structure and propagation of the genus Sagitta

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directions, perhaps gives the appearance of the partition on each side of the central one. The circulation at the base of the tail was twice as rapid as it was near the apex: where most rapid I found that a granule travelled over the 1/250th of an inch on the micrometer in five seconds; allowing for the slower rate in other parts, I calculated that in an individual, the tail of which was 3/20ths of an inch in length, a granule performed its entire circuit in about six minutes. I could distinctly follow the granules descending one column, turning the angle, and again ascending. In specimens with the reproductive |4| system in a lesser stage of development, the tail contained very little granular matter; and in proportion as this was less in quantity, so was the circulation less and less vigorous: in some specimens no granular matter, and perhaps, consequently, no circulation, was visible. When the tail is filled with vigorously circulating matter two large cul-de-sacs or gutshaped ovaries are invariably present, extending, as represented ( o o ) in the diagram, from the base of the tail along each side of the intestinal tube. These are filled with ova, which in the same animal are in different stages of development, and vary in length from 1/100th to 1/50th of an inch; their shape is pointed oval (Plate I. fig. B), and they are attached by the pointed end in rows to the sides of the ovaries: those of full size are detached by a very slight touch. When the ovaries contain many eggs nearly perfect (but not at other times), a small conical and apparently perforated protuberance can be seen on each side (A A) of the body, through which without doubt the eggs are expelled. In different individuals the ovaries are of different sizes and the eggs in different stages of development: before any of the eggs are perfected the ovaries are merely filled with granular matter; but this is invariably of a coarser texture than that within the tail. The ovaries when not containing granular matter are contracted into a very small size* (B). In great numbers of specimens taken in latitude 18° S. and between 37° and 40° S., I invariably observed that there existed a close relationship between the quantity of circulating matter within the tail and the size of the ovaries; from this circumstance, and from the similarity of the granular matter in the ovaries, before any of the eggs are perfected, with that in the tail, except that the granules are in this latter part of less size, I think it almost certain that the granular matter is first formed within the tail, and that it then passes into the ovaries, where it is gradually developed into ova. I could not, however, trace any opening from the one part into the other, but at the bottom of each ovary there was a space, where a closed orifice might have been situated. A well-developed egg presents, when liberated by a touch from a torn open ovary, the appearance represented at (B) in the diagram. The egg is transparent, and contains within it an exceedingly minute globule. Twice on one day and once again a week afterwards, I clearly observed the following curious phænomenon take place: the apex of the egg, a few minutes after having been liberated from its attachment, began and continued to |5| swell, and soon assumed the form shown by (C). Whilst this was going on, the small internal globule also appeared to be swelling, and at the same time the transparent fluid with which

*

I also remark in my MS. notes, that the granular matter within the tail is sometimes contracted into small kidney-shaped bodies; I cannot help suspecting that I ought in every case to have written that the ovaries were contracted into this form. [See Zoology notes, pp. 4–5 ff.]

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1844. Observations on the structure and propagation of the genus Sagitta

the ovum and its enlarged apex were charged, became more and more opake and granular. The apex continued enlarging until it became of nearly the same size with the ovum from which it proceeded; and as this took place, all the granular matter was slowly expelled from the original capsule into the newly-formed one, in a manner which seemed to show that it was effected by the contraction of a lining membrane as represented at (D). Directly that this was completed the two balls slowly separated; one being left a mere empty husk, and the other consisting of a spherical mass of granular matter, within which a minute globule could be discovered. I presume that this was the same globule as seen within the egg in its first state (as at B), and that the appearance of its swelling was caused by the transparent fluid round it being first converted into granular matter. I have reason to suppose from what follows that this little globule contains only air. The whole phænomenon was effected in about ten minutes; and in one case I watched the entire process without taking my eye from the microscope. On the 27th and 29th of September 1832, we passed* through the same tract of sea (off Bahia Blanca on the coast of northern Patagonia) where twenty-five days previously I had observed such great numbers of the S. exaptera with their ovaries distended with eggs, and I now found infinitely numerous ova floating on the surface. They were in different states of maturity; those least developed presented a sphere of granular matter contained within a larger spherical case. In the next stage the granular matter collects in a linear manner on one side of the inner sphere, and projects slightly beyond its outline; it then soon forms a distinct prominent rim, extending round two-thirds of the circumference of the inner sphere. This prominent rim is the young animal; a fine vessel is seen extending within its entire length, and one extremity enlarges into a head: the tail is first liberated from its attachment on the surface of the inner sphere, and lastly the head: the young animal, when thus released, lies in a curved position within the outer case, with the inner sphere, on the circumference of which it was developed, pushed on one side, and its function apparently ended. The central intestinal vessel is now much more distinct: an excessively fine membrane-like fin is discernible round the end of the tail; and the young animal being liberated from the outer spherical capsule, progresses by a |6| starting movement like that of a full-grown Sagitta. At the anterior extremity, near the head, a pulsating organ can be distinctly seen. The ovum in all these stages contains a minute globule, which causes it to float on the surface of the water, and apparently is formed of air: I presume that it is the same globule with that seen in the egg, when first released from the ovary. The change in the floating ova from the state in which the inner sphere consists of granular matter without any trace of a young animal to the succeeding states must be rapid; for on the 27th of September all the ova were in this first state, whilst on the 29th the majority contained partially developed young ones. These floating ova were 1/14th of an inch in diameter, whereas the spherical balls of granular matter which I saw expelled from their pointed oval cases were barely the 1/50th of an inch in diameter; but as the eggs within the ovaries were of different sizes, according to their states of maturity, we *

I may add, that in the beginning of April, off the Abrolhos, on the coast of Brazil, in lat. 18° S., numerous specimens of a four-finned Sagitta had their ovaries filled with eggs apparently ready to be expelled.

1844. Observations on the structure and propagation of the genus Sagitta

171

might expect that their growth would continue after having been expelled from them. I will conclude by expressing a hope that these few observations on the propagation of this curious genus may aid more competent judges than myself in ascertaining its true affinities.

Explanation of Plate I. I. o.o. A.A. T.T. B. C. D.

Intestinal tube. Ovaries. Apertures of the ovaries, and lateral fins. Tail divided into four columns of circulating granular matter, the course of which is shown by the arrows. Egg just liberated from the ovary. Egg in first state of change. Egg in a succeeding state.

172

1

2

1844. [Extracts from letters on guanacos]

Sagitta: carnivorous arrow worms (Chaetognaths). See Red notebook, p. 76, and Zoology notes, pp. 70–71. CD had originally intended to publish descriptions of the marine invertebrates from the Beagle voyage in Zoology (1838–43) these were deferred when the Government grant was exhausted. Green alga often called stoneworts.

1844. [Extracts from letters on guanacos]. In Walton, W., The alpaca: Its naturalization in the British Isles considered as a national benefit, and as an object of immediate utility. Edinburgh and London: William Blackwood & sons, pp. 43–4, 50–1. F18331 I have much pleasure in answering, as far as lies in my power, your enquiries regarding the guanaco. The first I killed was at Port Desire, on the coast of Patagonia; it weighed, without blood, entrails, or lungs, 170 lbs. Another, shot a few days afterwards, was estimated at a greater weight. These, and during |44| the succeeding year many others, were served out on board H. M. ship Beagle as fresh meat, and were generally liked. The meat, as far as I can remember, was fine-grained, not very dark, (perhaps of about the same colour as mutton,) rather dry, but not with the least bad taste or smell. I do not, however, think it would be considered of a very fine flavour; but, on the other hand, it must be remembered that the meat was tried in no other way (as I believe) except being baked in a ten gun brig’s stove, and that it was eaten very fresh. Moreover, these animals, shot in this wild state on the desert plains, were not fat. I cannot doubt that the guanaco, if domesticated and fattened, would yield a meat which, when well cooked, would be decidedly good, although possibly not equal to beef and mutton. |50| Perhaps there is no animal in the world which, in its wild state, flourishes under stations of such different, and indeed directly opposite characters, as the guanaco. I saw them on the hot deserts near Northern Chile, where the climate is excessively dry; on the borders of perpetual snow, at the height of 12,000 feet; and on the rocky and bare mountains of the |51| same country. They swarm in great herds on the most sterile plains of gravel, composing Patagonia. Formerly they were numerous on the grassy savannahs stretching on the banks of La Plata, where during half the year the summer is hot, and in the winter abundant rain falls; and lastly, the guanaco lives on the peat-covered mountains, and in the thick entangled forests of Tierra del Fuego, of which country the climate is far more humid and boisterous, and the summer less warm, than in any part of Great Britain. I could perceive no difference in the guanacos of these several regions. If the alpaca be the same species, or has the same constitution, as the guanaco, these facts regarding the range of the latter are interesting, as they show under what various conditions we might expect the alpaca to thrive. I will only add, that the guanaco so easily becomes tame, that young ones, caught and brought up at farm-houses, seldom leave them, although ranging at full liberty near their native plains.

1844. On the origin of mould

1

173

William Walton (1784–1857), writer on Spain and British agent in San Domingo, 1802–29. CCD2: 246–7.

1844. On the origin of mould. Gardeners’ Chronicle and Agricultural Gazette no. 14 (6 April): 218. F1665 As you have noticed a communication made by me to the Geological Society in 1837, on the Formation of Mould,1 I should be much obliged if you would correct an error into which I have fallen. In a postscript to that paper I state that marl was put on a pasture field, since ploughed, 80 years ago: I should have said 30 years, as I mistook the figures in the paper sent me. I found out this on visiting the place four years and a-half subsequently, and examining the old occupier of the farm.2 Wishing to ascertain the accuracy of the stated depth at which the marl now lies buried, I had three long holes dug in different parts of the field, and in each I found the marl, together with some cinders and broken pottery, in a layer 13 inches beneath the bottom of the potato-furrows, which were about four inches beneath the general surface; so that these substances are now buried at a depth of no less than 17 inches. They will never, probably, be undermined by the worms, to any much greater depth, as they almost rest on the general substratum of pure white sand. I particularly examined the occupier, whether the field had ever been ploughed to a greater depth than six or eight inches, and he positively assured me that it never had. My original informant, therefore, rather underrated the depth at which the marl now lies; although probably in the interval of four and a-half years, between our observations, some soil may have been removed by the worms from beneath the marl. In the other fields, formerly examined, I found that the layers of lime and cinders were, in almost every case, about an inch lower than they previously were. It was curious to observe in some of the holes how distinct three layers were preserved; the uppermost of cinders being two inches beneath the surface (on the former occasion one inch below), the middle layer of lime at four inches, and the lowest of cinders and burnt marl, at from 10 to 12 inches. I found this lowest layer wherever I dug, and likewise the other layers, but less regular, owing to different parts of the field having been limed and cindered at different periods. When digging in this field, after a long drought, I noticed, that one single clod of earth, about as large as a man’s two hands, was penetrated by eight upright, cylindrical worm-holes, nearly as large as swan-quills, so that I could see through them. Now this shows the quantity of earth in a small space, which is often probably removed by the worms and brought to the surface. The boggy field mentioned in the postscript to my Paper, on which two years and a half before a thick layer of bright red sand had been strewed, and which, I was informed, was then buried three-fourths of an inch beneath the surface, I found four years and a half subsequently (i.e. seven years from the sand being put on) was exactly two inches beneath the surface. In that field (also rather boggy) which I have described in my Paper, as first reclaimed 15 years before, the burnt marl was buried at a

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depth of four inches; so that in these two cases the rate of sinking, or more properly of being undermined, has been nearly the same, namely, about two inches in seven years. In the fields, however, more particularly alluded to in this notice, in which the marl that was put on thirty-four years and a half before, then lay seventeen inches beneath the surface, the rate of being undermined has been much quicker, namely, three inches and four-tenths of an inch every seven years. This field is dry, and consists of black, poor, very light sandy soil. It has also been ploughed, which may make some difference; though it is clear, from the uniformity of the layer, that the marl must have sunk beneath the depth at which the plough could disturb it before the pasture had been broken up. I am surprised at the red sand on the most boggy field having been buried as much as two inches in the seven years, for I never saw a field on which there were so few worm-castings. One cannot, however, judge of the number of worms in a field from inspection at any one season.—Charles Darwin, Down, Kent.

1 2

Darwin 1838, F1648, (p. 48) noticed in Gardeners’ Chronicle No. 11 (16 March 1844): 169. William Dabbs. CD’s source was a letter from Elizabeth Wedgwood, 10 November [1837], CCD2: 55–6.

1844. Manures and steeping seed. Gardeners’ Chronicle and Agricultural Gazette no. 23 (8 June): 380. F1666 Some of your readers may be amused at the style, as well as at the matter of the following quotations from “The Curiosities of Nature and Art in Husbandry and Gardening,” published in 1707.1 They show that the value of the inorganic parts of manure, and the advantage of steeping seeds, were well known at that time. “The whole secret of multiplication consists in the right use of salts. Salt, says Palissy,2 is the principal substance and virtue of dung. A field may be sown every year, if we restore to it by stercoration3 what we take from it in the harvest.” … “Seeing all multiplication depends on salts, the main business is to get together a great quantity at little expense, that the profit may be the greater.” The author then describes a method of making liquid manure, in three old casks, into which objects are separately thrown, according to the ease with which they decompose. He further urges the importance of burning all wild plants, and of carefully dissolving the soluble parts of their ashes, and then proceeds—‘Take as many pounds of saltpetre or nitre as you have acres of land to sow. For each acre dissolve a pound of saltpetre in twelve pints of the water that sanks from the dunghill. When the saltpetre is quite melted, throw in a little of those salts of plants (i.e. ashes) according to the quantity you have of them. This liquor is then called the ‘Universal Matter,’ because nitre is truly the universal spirit of the elementary world. This is the main point of the whole secret of multiplication. We will for the future call the water that is got ready in the casks, Prepared Water, and the water from which the salts are extracted from plants, and the nitre, Universal Matter. For one acre,

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take twelve pints of the prepared water, and mix with it immediately the universal matter, in which there ought to be a pound of dissolved nitre. The vessel into which you put these liquors must be large enough to contain the corn which you design for one acre. Then strew in your corn into these liquors; there must be two inches of water above the seed. Leave the corn to soak for twelve hours, and stir it up and down every two. If by that time it do not swell, let it lie longer till it begin to plump up considerably. One third less of seed than usual will serve for an acre; nay, you may safely use but half as much, and mingle among it some straw cut very small, that the sower may take it up by handfuls and sow it in the ordinary way, as I have said already.” The explanation the author offers of the use of soaking seeds is whimsical. He says that the first action is to “cut the covers that infold the sprouts,” and that the second action is “to serve each grain of corn, as it were, instead of a loadstone, to attract the nitre of the earth, which the subterranean fires have reduced and driven into steams and vapours in the low and middle region of the air, for the nourishment of vegetables and of animals. This is not a vain imagination, a chimera, or empty notion.”—C. Darwin.

1 2 3

Vallemont 1707. Palissy 1636. Referred to in Vallemont 1707, pp. 172–4. Manuring with dung.

1844. Variegated leaves. Gardeners’ Chronicle and Agricultural Gazette no. 37 (14 September): 621. F1667 Mr. Groom1 has stated in last Number that the leaves of some of his Pelargoniums have become regularly edged with white in consequence of his having watered the plants with sulphate of ammonia which had been exposed to the air for some time. Last autumn I planted many young Box-trees; and I have for some weeks observed that nearly all the young leaves in most of them are symmetrically tipped with white, giving the young branches a mottled appearance. I counted twelve trees thus affected. The older leaves are rarely tipped, with the exception of two bushes, in which they are regularly tipped, and the younger ones much less so. Mr. Groom states that in his Pelargoniums the older leaves are chiefly affected. The Box-trees are quite healthy, and growing well. I gave to some of them nitrate of soda, but it has made no difference in this variegation. Those growing in deep shade are not tipped, nor are some older trees. These facts may appear trivial; but I think the first appearance, even if not permanent, of any peculiarity which tends to become hereditary (as I fear is the case with the variegated Sycamore) deserves being recorded.—C. Darwin.

1

Possibly Henry Groom, nurseryman in Clapham Rise, London. See his remarks on pelargoniums in Gardeners’ Chronicle No. 36 (7 September 1844): 605 and CCD3: 62.

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1844. What is the action of common salt on carbonate of lime? Gardeners’ Chronicle and Agricultural Gazette no. 37 (14 September): 628–9. F1668 I should be extremely obliged if any of your chemical readers would inform me whether salt and carbonate of lime (under the form of sea-shells) would, if |629| slightly moistened and left in great masses long together, act in any degree on each other? It is, I believe, known that masses of the same substances will act on each other, of which smaller quantities will not. I do not ask this question for agricultural purposes (though possibly the answer might be of some interest in that point of view), but from having found in Peru a great bed of upraised recent shells, mixed with salt, which are decayed and corroded in a singular manner, so that the surfaces of the shells are scaling off and falling into powder.1 I may mention, as explaining one element in the value of sea-shells as manure, that they are dissolved by water with greater facility than apparently any other form of carbonate of lime: one proof of this I observed in a curious rock, from Chili,2 chiefly composed of small fragments of recent shells, which are all enveloped and cemented together by a pellucid calcareous deposit; but in some parts of this rock the little included fragments are in every stage of decay and disappearance; in other parts they are entirely dissolved, the little calcareous envelopes being left quite empty. Here we see that water, capable of dissolving shelly matter, has penetrated through their thin films or envelopes of carbonate of lime, without having acted on them; these films, moreover, being a deposition from water within quite recent times.—C. Darwin.3

1 2 3

See Journal of researches, p. 451, and South America, pp. 47–9, 52–3. See Volcanic islands, p. 144, and South America, pp. 36–7. The only response to CD’s letter was T. P. 1844. Manures and drainage. Gardeners’ Chronicle No. 40 (5 October): 675.

1844. Mr. Darwin’s Memorandum. In Henslow, J. S., Rust in wheat. Gardeners’ Chronicle (28 September): 659. F1668a Northern Bank of the Plata , Nov. 20–30, 1833. No. 1593.—Bearded Wheat materially injured by a blight, called the ‘Polvillo.’ When a field is attacked, it seems, even at a distance, burnt up, and of a red appearance. On walking amongst the Corn, the shoes and trowsers become covered with a fine rust-coloured powder: hence the name. The powder is lodged in minute oblong patches, beneath the epidermis, which may at first be seen partially raised, and forming a scale. It attacks all parts indiscriminately. If the leaves are a little infected, the grains of Corn are light and dry; but if the ear and stalk are attacked, the crop is entirely spoilt. The blight is not observed before the grain is pretty full; and its attacks are very rapid—three or four days being sufficient to spoil a whole field. It is endemic in the whole district, though not equally destructive throughout. From this cause, last year, when the weather was wet, no grain was gathered. Hence an immense importation of flour took place from North America. This year, the

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weather being fine and dry, the blight will destroy or injure the greater part of all the crops. Fields thrown up in Buts, clear of weeds, on high ground, are equally attacked with those of less favoured aspect. It is here attributed to the sun’s action after heavy dews. Crops grown from grain of the country, from the Cape of Good Hope, and from Rio Negro in Patagonia, were all more or less affected. It is remarkable that the Wheat at Rio Negro itself (which is grown on low diluvial lands) produced, even last year, its immense crop uninjured. This blight is a prodigious evil to the country, and most mortifying to the agriculturist, who does not know that all his labour will be lost, till within a week or fortnight of the time when he was expecting to reap the fruits of it.1 […] – J. S. Henslow, Hitcham, Sept. 9.

1

CD’s note is specimen not in spirits 1593 in Zoology notes, p. 394, and Porter 1987, p. 174.

[Darwin, C. R.] Kemp, W. 1844. An account of some seeds buried in a sand-pit which germinated. By Mr. William Kemp of Galashiels, in a Letter to Charles Darwin, Esq. Annals and Magazine of Natural History 13: 89–91. F19181 Having received early last spring some seeds, which were found at the bottom of a sand-pit upwards of twenty-five feet in depth, I most carefully examined into all the circumstances of their discovery. They were first seen by a respectable workman of the name of Thomas Welsh, who was excavating the finer sand at the bottom of the pit, in a part which was rather undermined; and fortunately Mr. John Bell of Melrose, the proprietor of the place, was looking on at the instant that they were disinterred. He kindly sent by Welsh some of the seeds to me, and I immediately returned with him, and in company with Mr. Bell carefully examined the layer in which they had been imbedded. The seeds were apparently of only two kinds; I sent specimens of them (through |90| Mr. Darwin) to Professor Lindley, and sowed the others myself. The plants reared by myself were sent to Professor Henslow, who states that they consist of Polygonum convolvulus and a variety of Atriplex patula; the seeds planted at the Horticultural Society by the kindness of Professor Lindley produced Rumex acetosella and an Atriplex, which was not at first recognised, but which Mr. Babington2 states is exactly like a variety of A. angustifolia which he has seen growing on mud in salt-marshes and on manure-heaps. The sand-quarry is situated about a quarter of a mile west of Melrose, and at the height of between fifty and sixty feet above the nearest part of the Tweed. The seeds were mingled with some decayed vegetable fibres, and formed a layer resting upon another layer, eight inches in thickness, of fine sandy clay. This latter lay over a mass of gravel, which again rested on a great mound belonging to the boulder formation. This mound, which extends about a mile along the middle of the valley, is about ninety feet in thickness, and I believe was formed by the action of glaciers. It contains enormous angular blocks of rock, and others smoothed and distinctly scored in lines parallel to their longer axes. The layer of

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sandy clay, on which the seeds rested, was capped by upwards of twenty-five feet in thickness of distinctly stratified sand, which has been largely quarried. The beds of sand vary in thickness and in fineness; sometimes they alternate with thin seams of impalpable clay, and sometimes they contain minute pebbles and fragments of carbonaceous, decayed wood. The layers slope at an angle of fifteen degrees towards the valley, and in this direction they thin out; the upper layers extend further into the valley than the lower ones; the entire mass has a level top, and is capped by some thin beds of fine gravel. From these several facts (as every geologist will admit), and from the general aspect of the layers of sand, it is scarcely possible to doubt that they were deposited by a river or torrent, at the point where it entered a sheet of water. I had long been of opinion that the valley of the Tweed in this part must formerly have been occupied by a lake, at a period when a great trap dyke, 100 yards wide, which crosses the valley four miles lower down at Old Melrose, had not been worn through. By an accurate levelling I have ascertained, that the layers of sand lie just beneath that level which a lake would hold, if the barrier at Old Melrose were reclosed. A depression on the surface of the land can, also, be distinctly followed from the spot where the sand-quarry is situated, up the valley, to where it joins the bed of the existing river; I cannot doubt that the Tweed anciently flowed in this depression, and deposited on the borders of the lake, the layers of sand where we now find them. It is certain that in the time of the Romans, about 2000 years |91| since, no lake existed here; and when we reflect on the time necessary to have worn down the barrier of trap-rock and to have drained so large a lake, which must have stood at its highest level whilst the thin layers of sand were deposited over the bed with the vegetable remains, the antiquity of these seeds is truly astonishing; and it is most wonderful that they should have retained their power of germination. As the plants raised are common British weeds, it is indispensable that I should detail the precautions which I took, to ascertain that they did not come from other seeds, existing in the soil in which they were planted. I first put all the seeds into a tumbler of water, and about one-fourth sunk to the bottom; of these I planted about three dozen, in parallel rows in flower-pots in my house and some others in the garden; and I carefully marked each row. Rather more than one dozen of these seeds germinated, so that of the seeds found only about one-tenth part produced plants. I watched from day to day their germination, and saw each little plant bring to the surface the husk of its seed; and these husks I compared under a microscope with other seeds which I had not planted. None of my plants at first grew vigorously. Five or six weeds appeared out of the rows, and these I picked up as they appeared and threw away. Of the two kinds of seeds sent to Professor Lindley, one was pronounced by him to be a Polygonum, and the other probably a Chenopodium; this latter genus belongs to the same natural family with Atriplex, and the seeds resemble each other. It is therefore certain that I planted seeds resembling those of Polygonum and Atriplex: now will any one believe, that, in the soil in the garden and likewise in the flower-pot (which in the latter produced only five or six weeds), there were accidentally lying, in exactly the same parallel rows in which I planted my seeds, above a dozen other seeds of these two genera? I think no one will imagine that this was the case. Moreover, the few seeds planted at the Horticultural Society produced an Atriplex and a Rumex: whether this latter plant was really

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produced from my seeds I do not know; but as its triangular seeds resemble those of Polygonum, I may have overlooked their difference, and have obtained these two kinds, besides the Atriplex, from the sand quarry. I hope that this account, besides establishing the fact that seeds may retain, when naturally preserved, their vitality for enormous periods of time,—from an epoch when the external features of the country were widely different,—will stimulate naturalists to search for seeds in the ancient alluvial deposits of other districts.

1

2

William Kemp was an amateur geologist and manager of the gas-works at Galashiels, Scotland, author of Kemp 1844. See CCD2, appendix VI which shows this item was drafted by CD. See Porter 1986. Charles Cardale Babington (1808–95) professor of botany, Cambridge 1861, succeeding Henslow.

1844. Brief descriptions of several terrestrial planariæ, and of some remarkable marine species, with an account of their habits. By Charles Darwin, F.R.S., V.P. Geol. Soc. Annals and Magazine of Natural History 14 (October): 241–51. F16691 In my Journal I have given a brief account of the discovery of several species of terrestrial Planariæ:2 it is my intention here to |242| describe them. They all belong to the genus Planaria, as restricted by A Dugès3 in his memoir* on these animals, and to that of Polycelis of Ehrenberg.4 They may, however, form a section of the genus, being characterized by their more convex and narrow bodies; their more distinctly defined foot, their terrestrial habits, and frequently by their longitudinal bands of bright colours. From their colours, from their convex bodies, from their manner of crawling and the track of slime which they leave behind, and from their places of habitation, they present a striking analogy with some terrestrial gasteropods, especially with Vaginulus, with which snail I have several times found them associated under stones. I suspect that, differently from their aquatic congeners, they live on vegetable matter, namely on decayed wood; I suspect this, from having found them repeatedly under this substance, and from having kept some specimens in a box for twenty-one days with nothing else for food, where they increased considerably in size. The species which live under stones, both on the grassy, undulating land of northern La Plata, and on the arid, rocky hills of central Chile, generally inhabit small sinuous chambers, like those frequented by earth-worms, in which they lie coiled and knotted up. They are often found in pairs; and I once discovered a pair attached together by their lower surfaces, apparently in copulation. None of these species have the quick and vivacious movements of the marine species: they progress by a regular wave-like movement of the foot, like that of a gasteropod, using the anterior extremity, which is raised from the ground, as a feeler. One species which I tried could crawl well through moss; another being placed on dry paper was almost killed by it. I put several specimens into fresh water, but they appeared wholly *

Annales des Science Naturelles, October 1828.

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unused to it, and would soon have perished: they seem, however, to prefer damp situations, and the specimens of P. Tasmaniana, which I kept in a box with rotten wood, having been neglected to be moistened, all perished, except one large individual which survived quite uninjured, although the wood had become perfectly dry. These animals (especially the P. Tasmaniana) had an immediate apprehension and dislike of light, which they showed by crawling, when the lid of the box was taken off, to the under side of the pieces of rotten wood. My observations, as far as they go, on the structure of these terrestrial species, agree with those given by Dugès on the structure of the aquatic species. The figure given by this author of the ramified digestive vessels of P. lactea is quite similar to a drawing that I made of this part in the P. pallida from Valparaiso (which, from being nearly colourless, allowed the best opportunity of observation), |243| except in the entire absence of ramifications on the internal sides of the two posterior prolongations of the main digestive cavity. There is generally a colourless space round the alimentary and genital orifices. The mouth-sucker is bell-shaped, with a very short œsophagus: when contracted it forms either a globular or star-shaped hard ball: I never saw it voluntarily protruded, but have no doubt that it can be, for immersion into very weak spirits of wine or salt water caused its exsertion, and on being touched it was immediately retracted. This mouth-sucker is highly contractile, and retains its irritability long after the death and even dissolution of the rest of the body: the external orifice, through which it is protruded, consists of a transverse slit. The genital orifice, also, consists of a transverse slit; in the aquatic species it is generally, if not always, circular. In my notes5 on several of the species, I find it stated that the under surface or foot is thickly studded with very minute, angular, opake, white specks: may not these serve for the necessarily copious secretion of slime? These animals, when placed on a slip of glass, frequently propelled a globule of air, between their foot and the glass, from their anterior extremity towards their tail; and as the air came in contact with successive parts of the foot, a violent corpuscular movement (curiously resembling microscopical eels disturbed by a stick, and struggling in mud) was produced in the slimy surface. I could never perceive it in any part of the foot, except when in contact with air; but it was evident, though less energetic, on parts of the back, and at the extreme anterior extremity of the body. I presume that the appearance is due to vibratile cilia; and it is worthy of remark, that M. Dugès* suspects that the foot, in the freshwater species, is the chief seat of this respiratory action, from having observed that they frequently arch their bodies, so as to allow fresh water to circulate under it. The position of the black eye-spots varies in the different species: it is remarkable that, in the P. elongata from Tres Montes, I could perceive no trace of these ocelli,6 although this is the largest species. According to Prof. Ehrenberg’s arrangement, depending on the presence and number of the ocelli, this species would rank in his genus Typhoplana; but from the variability in number and position of these imperfect organs of vision, I should doubt whether they ought to afford generic characters. In the P. pallida I examined the ocelli with a strong lens, and found that they were not truly circular; the black part lies within a transparent envelope; in this species they are seated on the upper margin of *

Annales des Sciences Naturelles, October 1828, p. 28.

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the body, in groups of two and three, exactly over the extreme lateral subdivisions of the intestinal vessel. I was not able to see ova |244| within any of the terrestrial species. The texture of the body, its prompt dissolution into fluid after death, its power of healing wounds, its irritability and contractile powers, appear to be exactly similar in the terrestrial and in the aquatic species, as described by Dugès. I will not here repeat the description which I have given in my Journal (p. 31) of the bisection of the P. Tasmaniana, and the production of two perfect individuals (with the exception of the external orifice for the mouth-sucker) in the course of twenty-five days. I will only add, that an individual being divided into many fragments, each crawled in the proper direction, as if furnished with its proper anterior extremity. I found altogether twelve terrestrial species; two in the forests of Brazil; three on the grassy, open country northward of the Rio Plata; one on the arid hills near Valparaiso in Chile, and three in the damp wooded country southward of central Chile: the most southern locality was in lat. 46° 300 S. I found also one species in New Zealand (which I lost), another in Van Diemen’s Land, and a third at the Mauritius; the latter I had not time to examine. Hence it appears that the terrestrial section of this genus is widely diffused; but as far as is at present known, only in the southern hemisphere. The existence of terrestrial Planariæ is analogous to that of terrestrial leeches in the forests of southern Chile and of Ceylon. 1. Planaria vaginuloides Alimentary orifice situated at two-thirds of the entire length of the body from the anterior extremity; width of orifice 1/60th of an inch: at the distance of 3/10ths of an inch posteriorly, lies the genital orifice, very plainly marked. Ocelli numerous, placed at regular intervals on the anterior extremity; irregularly, round the edges of the foot. Anterior part of the body elongated, with the extremity much pointed and grooved on the under side: tail bluntly pointed; body convex, flattened on the top. Sides and foot coloured dirty “orpiment orange”;* above, with two stripes on each side of pale “primrose-yellow,” edged externally with black; on centre of the back a stripe of glossy black; these stripes become narrow towards both extremities. Length when fully extended 2 3/10ths of an inch; breadth in broadest part 13/100ths of an inch. Hab. Under the bark of a decayed tree in the forest: Rio de Janeiro (June). 2. Planaria elegans Position of the orifices as in P. vaginuloides. Anterior part of the body little elongated. Ocelli absent on the anterior extremity, and only a few round the margin of the foot. Colours beautiful; back snow-white, with two approximate lines of reddish brown; near the |245| sides with several very fine parallel lines of the same tint; foot white, exteriorly clouded, together with the margin of the body, with pale blackish purple: body crossed by three colourless rings, in the two posterior of which the orifices are situated. Length 1 inch; breadth more uniform, and greater in proportion to length of body, than in the last species. Hab. Same as in P. vaginuloides. *

The colours, when placed between inverted commas, signify that they are given by comparison with Patrick Syme’s Nomenclature. [Patrick Syme (1774–1845), flower painter and drawing master. Syme 1821. This work contained plates of standardized tints for identifying the colours of specimens when collected.]

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3. Planaria pulla Mouth-sucker, when protruded and contracted in spirits of wine, globular. Ocelli numerous, placed at regular intervals on the anterior part of the body. Body slightly flattened, gradually increasing in width from the anterior extremity, which is much pointed and grooved beneath. Back rich “umber-brown,” with a central narrow streak of “broccoli-brown” reaching entire length: foot broccoli-brown, with two clear spaces for the orifices. Length when fully extended 1 9/10ths of an inch; breadth 1/10th of an inch. Hab. Very frequent under stones: Monte Video and Maldonado (June and August). 4. Planaria bilinearis Ocelli numerous, placed at regular intervals. Body subcylindrical, narrow, of nearly uniform breadth. Colour above pale dirty yellow with two stripes of “umber-brown,” which become narrower and unite at the two extremities. Length when fully extended 1 3/10ths; breadth 7/100ths of an inch. Hab. Same as P. pulla (June and August). 5. Planaria nigro-fusca Alimentary orifice situated at rather less than two-thirds of the entire length from the anterior extremity: genital orifice, with the body contracted, is situated at the 25/100ths of an inch posteriorly. Ocelli very numerous; those on the extreme tip very minute and placed at regular intervals; those on the margin of the body grouped by two and three together. Body much depressed, tapering suddenly towards the anterior extremity; tail abruptly terminated in a point. Above uniform blackish brown, beneath pale. Length when fully extended 2 inches; breadth 3/10ths of an inch. Hab. Under rotten wood: Maldonado (May). 6. Planaria pallida The alimentary and genital orifices 2/10ths of an inch apart, when the body is partially contracted: mouth-sucker when dissected out of the body 15/100ths of an inch in length; its margin very sinuous. Ocelli numerous; eleven close together, being placed on the anterior extremity; and the others in groups of two and three on the sides, and chiefly on the anterior half of the body. Body much depressed and flat, with both extremities finely pointed. Upper and lower surfaces white, with the pinkish intestinal vessel seen through. Length when crawling 3 inches; breadth 2/10ths of an inch. Hab. Under stones on the dry hills near Valparaiso (July). |246| 7. Planaria elongata Alimentary and genital orifices obscure. Ocelli absent: posterior extremity very obtusely rounded. Above “umber-brown,” with a narrow medial line of darker brown; sides narrowly edged with pale brown, bordered with the umber-brown; beneath pale brown. Length when crawling 5 inches, when closely contracted 1 4/10ths of an inch, breadth when crawling 13/100ths, when contracted 4/10ths of an inch.

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Hab. On rotten wood in mountain-forests: C. Tres Montes, lat. 46° 300 S., Western America (December). 8. Planaria semilineata Body convex. Above greenish black, with minute white punctures; on anterior half of body four parallel bands of “gall-stone yellow,” of which only the central and approximate pair are prolonged into the posterior half of body: foot leaden colour, with colourless spaces for the orifices. Hab. Under stones, on one of the Chonos Islands (north of C. Tres Montes) (December). 9. Planaria maculata Edges of the body very thin; breadth nearly uniform. Upper surface quite black, with numerous, oblong, variously sized spots of yellow: foot mottled white and black. Length when crawling 1 7/10ths; breadth 2/10ths of an inch. Hab. Forest of Valdivia (February). 10. Planaria Tasmaniana Mouth-sucker widely extensile: alimentary orifice placed nearly in centre of the body; genital orifice 1/10th of an inch posteriorly, but when the animal crawls it is 2/10ths of an inch distant. Genital orifice very distinct, submargined. Ocelli scattered round the entire margin of the foot, but most frequent at the anterior extremity. Both extremities pointed. Colour dirty “honey-yellow,” with a central dark brown line bordered on each side with a broader line of pale “umber-brown:” foot quite white. Length when crawling 1 5/10ths; when contracted 8/10ths of an inch. Hab. Beneath decayed trees in the woods of Van Diemen’s Land: frequent (February). I will now briefly describe five marine species of Planaria, which are remarkable, either as presenting novel points of structure, hereafter probably forming the types of new subgenera, or from the situations which they inhabit. 1. Planaria (?) oceanica. Plate V. fig. 1. Under-surface magnified Anterior extremity neck-shaped, with two ear-like processes. |247| Ocelli, I believe, absent. Posterior extremity broadly rounded. Membranous margin of body jagged. Length 2/10ths of an inch. Colour pale, uniform. Near the neck there is a quadrangular, internal, clear space, apparently lined by a membrane, within which there is a dark-coloured spot, and externally close by it an orifice, which the animal can dilate and contract at pleasure. Close behind this there is an internal oval space, within which there is a second dark spot united to a delicate vessel; I was unable to distinguish any orifice near this point: these organs form, I presume, the reproductive system. Close behind these organs there is a dark space formed by the union of eleven, branching, intestinal cavities, in the centre of which there is a longitudinal orifice situated rather behind the centre of the body.

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Through this orifice the animal can protrude a folding mouth-sucker: when it begins to unfold it is seen to be drawn into eight folds, as represented at (B). Hab. Open ocean, lat. 5° S., long. 33° W. (February). This I believe is the first instance of a species of this genus being found in the open sea, at the distance of 150 miles from the nearest part of S. America, and 80 miles from the small island of Fernando Noronha. 2. Planaria (?) formosa Body much depressed, oval. In the posterior half, on the under side, there is a very large alimentary orifice with folding lips (but apparently with no exsertile mouth-sucker), from which the two main intestinal cavities branch. Near the anterior extremity there is a minute orifice, and between it and the mouth a second orifice: these the animal can dilate and contract; they lie over an opake, wedge-formed, internal mass, and form, I presume, two genital orifices. Back dotted with purplish red, with a central band of “vermilion-red,” edged with white: this band sends off three branches on each side; at the extremity of each of the two anterior branches there is a longitudinal group of black ocelli, and before these two other circular groups, forming together four groups of ocelli. Length when extended half an inch. Inactive in its movements. Hab. On corallines, at a depth of 30 fathoms, in southern Tierra del Fuego (December). 3. Planaria (?) macrostoma. Plate V. fig. 2. Under-side magnified External alimentary orifice situated in the posterior half of body: mouth-sucker nearly subcylindrical, bell-shaped, very long; when contracted within the body it lies in a serpentine position; when partly protruded it has the figure as represented; when fully extended it tapers only slightly from its mouth to its base, and is so long, that the animal can pass it from the under surface over the entire width of its back. Its base is united, in the middle of the body, to the three principal branches of the intestinal cavity; the two posterior branches unite and form a ring, enclosing the space in which the |248| mouth-sucker and its external orifice are situated. The three main branches receive the moss-like subdivision of the intestinal cavity, which reach all round nearly to the margin of the body. The main, medial, intestinal cavity ends at the anterior extremity in a small, opake, wedge-formed mass; on each side of which, nearly on the dorsal surface, a black ocellus is situated. Between the lateral branches on each side of the medial cavity, seven or eight internal spherical cavities lie, including opake balls, which I presume are immature ova; the anterior ones were most developed: they were not present in the smaller specimens, or in all the full-grown ones. I was unable to discover any genital orifice, though no doubt one or two exist: near the posterior extremity (at B) there was a colourless space, but I could not see any orifice. Anterior extremity square, truncate, with the edges thin and prehensile; the animal attaches itself by this part, almost like a leech with its sucker, and thus drags its body: posterior extremity broadly rounded. Above, faintly coloured brownish purple in striæ, with a colourless space over the alimentary orifice. Length 2/10ths; breadth 6/100ths of an inch.

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Hab. Congregated in numbers under stones, in brackish water; Chonos Archipelago (west coast of S. America) (December). The arrangement of the main branches of the intestinal cavity is the same as in the terrestrial Planariæ, with the exception of the two posterior branches being united near the extremity of the body into a ring, which structure I have not met with described in any other species. Hence this species probably ought to form the type of a new subgenus. I may here mention that I found amongst these islands an elongated marine species (with a very distinctly formed head placed on a narrow neck) which had the power of crawling either backwards or forwards,—a power I have never seen in any other species. 4. Planaria (?) incisa. Plate V. fig. 3. Under-surface magnified Body oval, very much depressed, highly contractile; margin sinuous, anteriorly deeply indented, posteriorly less so. Ocelli very numerous and crowded together in several rows on the indented anterior (as is known by its progression) margin. Along the centre of the body an intestinal vessel extends, and in the middle of this (B) there is a well-closed orifice, through which the animal can protrude a thin, much-folded, sinuated mouth-sucker; this when fully expanded is quite as wide as the body. Posteriorly, on each side of the central vessel, there is a mass, apparently of immature ova. Near the posterior extremity there is a second subterminal orifice (D), through which, when the animal was placed in spirits, a little globular mass was protruded, like a small, much-contracted mouth-sucker. Near to the anterior extremity there are two slightly retractile paps with orifices, of which the anterior one is the largest. From this point diverging rays (intestinal cavities ?) are sent off, which reach nearly |249| to the margin of the entire body: when the animal contracts itself, the back is raised in slight ridges, corresponding with these rays. This species, therefore, has four orifices on its under surface. Back finely reticulated with brownish purple. Length 1 inch; breadth three-quarters of an inch. Hab. Under stones on the sea-beach, St. Jago; Cape Verd Archipelago (February). This species is exceedingly active and irritable in its habits: it lives, like a Nereis,7 under stones firmly imbedded in the beach at low-water mark. It has the power of adhering with great tenacity to smooth stones: another allied species had the same power, could also swim well by a vertical movement of its body, and frequently rolled itself into a ball. With respect to the four orifices: I presume, as in the P. formosa, the two anterior ones belong to the reproductive system. The central orifice undoubtedly is the mouth: the posterior one would naturally be thought to be the anus; but I am doubtful of this, considering the little globular body which was protruded through it, and from the existence in the following allied genus of a double mouth. Diplanaria (nov. genus) Alimentary orifice double, with two exsertile mouth-suckers. Two genital orifices in the posterior part of the body. A large forked ovarium (?). Ocelli in four groups, two superficial and two more deeply seated. The characters here given appear to me absolutely to require the institution of a new genus.

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Diplanaria notabilis. Plate V. fig. 4. Under-side magnified Body very much depressed, with the edges very thin; anterior extremity thrice as broad as the posterior. On the under surface, towards the anterior extremity, there is a clear space, over which, on the back, the ocelli are situated; into this space, on all sides, the branching, clear, intestinal cavities enter. Each intestinal cavity generally bifurcates three times before its fine extremities reach the margin of the body. Towards the posterior extremity there is a second clear space (with the two orifices D and E), into which also the surrounding intestinal branching cavities enter; these two spaces are united by two longitudinal clear spaces (obscured by ovules in the drawing) passing on each side of the elongated, opake, white, central organ. This organ, when the animal is contracted, has the appearance represented in the drawing, namely of an internal, elliptic mass, narrowing at each end, with deeply sinuated borders, and with two external, perfectly closed orifices over it, as shown at (B) and (C). But when these two orifices are opened, from both of them broad, shallow, saucer-like mouth-suckers are protruded, as represented at (F); these, when contracted within the body, appear united, |250| and form a single, elliptic, sinuated body. These two mouth-suckers are quite similar; they are much shallower than those of any other species of the family which I have seen; their membranous edges are very thin, narrow, transparent and sinuous: in the act of contraction they become folded in a complicated manner, like the bud of a flower. I was able easily to dissect them out of the body, and they retained, in the characteristic manner described by Dugès, and as in the terrestrial Planariæ, an extreme degree of irritability and contractile power, long after the rest of the body had ceased to live. In the elliptic space surrounding the two mouth-suckers when contracted, and between the mouths of the lateral, branching, intestinal cavities, innumerable ova are arranged in groups, from two to four in each; these are represented in the drawing only by double dots. These ova were easily separated; they are spherical, 5/500ths of an inch in diameter, and contain a central opake mass. In the posterior clear space there are two minute, but quite distinct, orifices (D and E), which I do not doubt are the reproductive pores: into this clear space a large fork, filled with opake white matter, enters, as is shown in the drawing; this matter consists of minute, white globules in chains, imperfectly united together: I believe these are immature ova, and hence I suppose that the fork is the ovarium, from which the ova pass into the clear spaces surrounding the mouth-suckers and are there matured. The ocelli are black and circular, and are arranged in four groups, two of which are round, and two in elongated bands inclined to each other: the ocelli in the bands are not seated on the dorsal surface, but deep within the body, near the ventral surface. Colour pale “tile-red,” darkest on the dorsal ridge, with colourless spaces over the genital orifices and over the ocelli. Length 55/100ths of an inch; breadth of anterior part of body 3/10ths; of posterior part 1/10th of an inch. Hab. Under stones in tidal pools, Chonos Archipelago (Western S. America) (December). This animal is very active, can crawl quickly, and can swim well by the movements of its thin marginal edges: it can adhere firmly to stones.

1844. Brief descriptions of several terrestrial planariæ

187

This is the most complicated and singular form of the large family of Planariæ which I have seen or met with described. The presence of two alimentary orifices and two mouth-suckers is another and interesting point of affinity between the Planariæ and the true parasitic worms, in which the number of mouths so often exceeds one. I believe that the presence of the large forked ovarium, and of groups of ocelli situated at different depths, are peculiarities of structure confined to this genus. If the small mass protruded from the posterior orifice (D) of the Planaria (?) incisa was really a small contracted mouth-sucker, this species is closely allied to our present new genus; with the chief difference of the two genital orifices being near the anterior, instead of the posterior extremity. |251| I will conclude by remarking, that the family of Planariæ is most widely diffused, and is adapted to the most different stations: on the land, it is adapted to forests and plains, in hot, temperate, and dry climates; in water, under all latitudes, to fresh, brackish and salt, on sea-beaches, at the depth of 30 fathoms, and in the open ocean.

1

2 3 4 5 6 7

CD had originally intended to publish descriptions of the marine invertebrates from the Beagle voyage in Zoology (1838–43), these were deferred when the Government grant was exhausted. After this paper CD wrote another on his curious parasitic barnacle, which was not published. Instead CD gradually took up the whole sub-class publishing his results in 1851–4. Flatworms. See Journal of researches, p. 30. Antoine Dugès (1797–1838), French physiologist. Dugès 1828. Ehrenberg 1831. See Zoology notes. Simple eyes. Ragworms.

188

1845. [Letter on Patagonian stone]

1845. Extracts from letters to the General Secretary, on the analogy of the structure of some volcanic rocks with that of glaciers. By C. Darwin, Esq., F.R.S. Specimens were exhibited. With observations on the same subject by Prof. Forbes. [Communicated by J. D. Forbes. 3 February] Proceedings of the Royal Society of Edinburgh 2: 17–18. F1670 I take the liberty of addressing you, knowing how much you are interested on the subject of your discovery of the veined structure of glacier ice. I have a specimen (from Mr. Stokes’s1 collection) of Mexican obsidian, which, judging from your description, must resemble, to a considerable degree, the zoned ice. It is zoned with quite straight parallel lines, like an agate; and these zones, as far as I can see under the microscope, appear entirely due to the greater or lesser number of excessively minute, flattened air cavities. I cannot avoid suspecting that in this case, and in many others, in which lava of the trachytic series (generally of very imperfect fluidity) are laminated, that the structure is due to the stretching of the mass or stream during its movement, as in the ice-streams of glaciers. * * * If the subject of the lamination of volcanic rocks should interest you, I would venture to ask you to refer to p. 65–72 of my small volume of ‘Geological Observations on Volcanic Islands.’ I there |18| throw out the idea, that the structure in question may perhaps be explained by your views on the zoned structure of glacier ice, the layers of less tension being, in the case of the Ascension obsidian-rocks, rendered apparent, chiefly by the crystalline and concretionary action superinduced in them, instead of, as in zoned ice, by the congelation of water. * * * How singular it at first appears, that your discoveries in the structure of glacier ice should explain the structure, as I fully believe they will, of many volcanic masses. I, for one, have for years been quite confounded whenever I thought of the lamination of rocks which have flowed in a liquified state. Will your views throw any light on the primary laminated rocks? The laminæ certainly seem very generally parallel to the lines of disturbance and movement. Believe me, &c.C. Darwin. To Professor Forbes.2

1 2

John Lort Stokes (1812–85), naval officer and mate and Assistant Surveyor aboard the Beagle with CD. The specimen is discussed in Volcanic islands, pp. 67, 69–70. James David Forbes (1828–76), professor of natural philosophy, Edinburgh University, 1833–60, secretary of the Royal Society of Edinburgh, 1840–51. This item was reprinted verbatim in Forbes 1859. See CCD3: 66; 74. Forbes comments are here omitted. (DO)

1845. [Letter on Patagonian stone]. In Ehrenberg, C. G. Vorläufige zweite Mittheilung über die . . . Beziehungen des kleinsten organischen Lebens zu den vulkanischen Massen der Erde. Bericht über die zur Bekanntmachung geeigneten Verhandlungen der Königlichen Akademie der Wissenschaften zu Berlin, pp. 143–4. F1989 Ich danke Ihnen für Ihre Bemerkungen über die weiße Patagonische Felsart. Ich bin aus verschiedenen Gründen zu demselben Resultate mit Ihnen gekommen, dass sie ursprünglish

1845. [On an edible fungus from Tierra del Fuego]

189

ein vulkanisches Gebilde ist. Unglücklicherweise melden Sie mir nicht, welche von den Proben des weissen Gesteins Infusorien enthält, ich glaube, ich sandte mehrere mit Angabe ihrer Fundorte.* Die Formation ist eine grossartige. Sie ist in Verbindung mit vielem Gyps (sulphate of lime), hat die Consistenz unserer Kreide (chalk), ist vielleicht etwas weicher, und hat eine ungeheure Ausdehnung. Zu Port St. Julian kann sie nicht weniger asl 800 Fus Mächtigkeit haben. Sie erstreckt sich im Zusammenhange 200 geographische Meilen weit (wahrscheinlich ist sie von grosser Breite), und ist, wie ich glaube, von noch weit grösserer Ausdehnung, denn ich habe Proben aus den nördlichen Theilen von Patagonien und aus Lagern, welche genau |144| dieselben äusseren Character haben vom Rio Negro, das giebt eine Ausdehnung von Norden nach Süden von wenigstens 550 Meilen. English translation: I have to thank you for your remarks on the white Patagonian rock, and to state that for many reasons I had arrived at the same conclusion as yourself, that it is originally a volcanic product. Unfortunately you do not mention which of the specimens of white stone contain infusoria, and I think I forwarded several, with their localities marked.† The formation is on a grand scale; it contains much gypsum, it has the consistence of our chalk, but is perhaps somewhat softer, and it has an enormous extension. At Port St. Julian it cannot be less than 800 feet thick. Its average breadth is at least 200 miles, and probably more, while it extends from north to south at least 550 miles.1

1

This contemporary English translation is from Ehrenberg 1846, p. 87. See CCD3: 161. See also Journal of researches 2d ed., pp. 129–30.

1845. [Extracts from Darwin’s notes.] In Berkeley, M. J., On an edible fungus from Tierra del Fuego, and an allied Chilian species. [Read 16 March 1841] Transactions of the Linnean Society of London 19: 38–9, pl. 4. F1671 “In the beech forests,” says Mr. Darwin,1 speaking of Tierra del Fuego, “the trees are much diseased; on the rough excrescences grow vast numbers of yellow balls. They are of the colour of the yolk of an egg, and vary in size from that of a bullet to that of a small apple; in shape they are globular, but a little produced towards the point of attachment. They grow both on the branches and stems in groups. When young they contain much fluid and are tasteless, but in their older and altered state they form a very essential article of food for the Fuegian. The boys collect them, and they are eaten uncooked with the fish. When we were in Good Success Bay in December they were then young; in this state they are externally quite smooth, turgid, and of a bright colour, with no internal cavity. The external surface was marked with white spaces, as of a membrane covering a cell. Upon keeping one in a drawer, my attention was called, after some interval, by finding it become nearly *

Ich hatte sie in allen Proben gefunden.

†

The author had found these remains in all the specimens.

190

1845. [On an edible fungus from Tierra del Fuego]

dry, the whole surface honeycombed by regular cells, with the decided smell of a Fungus, and with a slightly sweet mucous taste. In this state I have found them during January and February (1833) over the whole country. Upon dividing one, the centre is found partly hollow and filled with brown fibrous matter; this evidently merely acts as a support to the elastic semitransparent ligamentous substance which forms the base and sides of the external cells. Some of these balls remain on the trees nearly the whole year; Captain Fitzroy has seen them in June. “Feb. 1834. Port Famine. When young, colour ‘ochre-yellow and Dutch-orange’ of the Wernerian nomenclature;2 smell strong; taste sweet. From the root a hollow vessel passes to the centre, from which white ligamentous rays extend through the semi-gelatinous mass to the bottom of the cells. “June 1834. Found some very turgid, and highly elastic; a section of the central parts white, and the whole, under a high power, looking like a vermicelli pudding, from the number of small thread-like cylinders. At about one-twentieth of an inch from the external surface, there were placed, at regular intervals, small cup-shaped bodies, one-twelfth of an inch in diameter, of a bright ‘Dutch-orange.’ The cup was filled with adhesive, elastic, colourless, quite transparent matter; and hence at first appeared hollow. The upper |39| edge of the cup was divided into conical points about ten or twelve in number, and these terminated in an irregular bunch of the above-mentioned threads; the cup was easily detached from the surrounding white substance, excepting at the fringed superior edge. Over the cup was a slight pit in the exterior surface: this afterwards becomes an external orifice to the cup, when the gelatinous mass has perhaps formed seeds.” Mr. Darwin found them much infested with larvæ, to which undoubtedly the cavity in many specimens is owing. The following observations in Mr. Darwin’s notes refer to the species noticed by Bertero:—3 “Sept. 1834. On the hills near Nancagua and San Fernando there are large woods of Roble, or the Chilian oak. I found on it a yellow fungus, very closely resembling the edible ones of the beech of Tierra del Fuego. Speaking from memory, the difference consists in these being paler coloured, but the inside of the cups of a darker orange. The greatest difference is, however, in the more irregular shape, in place of being spherical: they are also much larger. Many are three times as large as the largest of my Fuegian specimens. The footstalk appears longer; this is necessary from the roughness of the bark of the trees on which they grow. In the young state there is an internal cavity. They are occasionally eaten by the poor people. I observe that these are not infested with larvæ, like those of Tierra del Fuego.”4

1

2

See Beagle plants and Zoology notes, p. 126 ff. Miles Joseph Berkeley (1803–89), clergyman, botanist and expert on British fungi. A summary of Berkeley’s article appeared in Proceedings of the Linnean Society of London 1: 97–8. Syme 1821.

1845. Testimonials in favour of Joseph Dalton Hooker 3 4

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Carlo Giuseppe Bertero (1789–1831), Italian physician, botanist and traveller. Bertero’s work was translated in Ruschenberger 1838. The remainder of the article by Berkeley is omitted. (DO)

1845. Additional testimonials submitted to the Council of University College, London, by Edward William Brayley... a candidate for the Professorship of Geology. London: Richard & John E. Taylor, p. [7]. F324a Down, Kent Feb. 7th. 1845. My dear Sir You have my best wishes for your success in your present application. You are aware that I have never had an opportunity of hearing you lecture, & therefore cannot speak of your qualifications in that line; but I have great pleasure in adding, that I have always been struck by your remarkable powers in acquiring scientific knowledge of varied kinds, & by your extensive reading. I think it will be generally acknowledged, that a capacity of this nature, must be eminently serviceable in teaching a subject of so divesified a nature as Geology.— Believe me dear Sir Yours very faithfully C. Darwin E. W. Brayley Esqe1

1

Edward William Brayley (1802–70), geologist and free-lance lecturer. It was customary in the nineteenth century for applicants for Chairs to send printed letters with supporting testimonials to be distributed amongst the members of selecting bodies. This application was not successful. See Freeman 1977 and CCD3: 133.

1845. [Testimonial.] In Testimonials in favour of Joseph Dalton Hooker R. N., M. D., F.L.S. as a candidate for the vacant chair of botany in the University of Edinburgh. Second series [of four]. Edinburgh: Neil and Co., p. 25. F2030 XXXVII.—From Charles Darwin, Esq., M.A., F.R.S. & G.S., late Naturalist to Captain Fitzroy’s Voyage. Down House, Farnborough, August 25. 1845. Dear Sir William,—I have heard with much interest that your Son, Dr Hooker, is a Candidate for the Botanical Chair at Edinburgh. From my former attendance at that University, I am aware how important a post it is for the advancement of science, and I am therefore the more anxious for your Son’s success, from my firm belief that no one will fulfil its duties with greater zeal or ability. Since his return from the famous Antarctic Expedition, I have had,

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1846. An account of the fine dust which often falls on vessels in the Atlantic ocean

as you are aware, much communication with him, with respect to the collections brought home by myself, and on other scientific subjects; and I cannot express too strongly my admiration at the accuracy of his varied knowledge, and at his powers of generalization. From Dr Hooker’s disposition, no one, in my opinion, is more fitted to communicate to beginners a strong taste for those pursuits, to which he is himself so ardently devoted. For the sake of the advancement of Botany in all its branches, your Son has my warmest wishes for his success. Believe me, dear Sir William, yours very faithfully, Charles Darwin. To Sir William Hooker, Royal Botanic Gardens, Kew.1

1

There were 153 testimonial letters printed for Joseph Dalton Hooker (1817–1911), botanist, assistant director, Royal Botanic Gardens, Kew, 1855–65; director, 1865–85, became one of CD’s closest friends and supporters. Hooker’s application was unsuccessful. See CCD3: 240.

1846. [Note on sandstone and query on coral reefs]. In Stokes, J.L., Discoveries in Australia. London: T. & W. Boone, vol. 1: 108, 331. F1915 Since this was written, I have consulted my friend, Mr. Darwin, who has kindly examined a specimen I brought away. He pronounces it “a superficial highly ferrugineous sandstone, with concretionary veins and aggregations.” |308| Are there masses of coral or beds of shells some yards above high water mark, on the coast fronting the barrier reef?1

1

See CCD13: 345.

1846. An account of the fine dust which often falls on vessels in the Atlantic ocean. By Charles Darwin, Esq., F. R. S., F. G. S. [Read 4 June 1845] Quarterly Journal of the Geological Society of London 2: 26–30. F1672 Many scattered accounts have appeared concerning the dust which has fallen in considerable quantities on vessels on the African side of the Atlantic Ocean. It has appeared to me desirable to collect these accounts, more especially since Professor Ehrenberg’s1 remarkable discovery that the dust consists in considerable part of Infusoria2 and |27| Phytolitharia.3 I have found fifteen distinct statements of dust having fallen; and several of these refer to a period of more than one day, and some to a considerably longer time.

1846. An account of the fine dust which often falls on vessels in the Atlantic ocean

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Other less distinct accounts have also appeared. At the end of this paper I will give the particular cases, and will here only refer to the more striking ones and make a few general remarks. The phænomenon has been most frequently observed in the neighbourhood of the Cape Verd Archipelago. The most southern point at which dust is recorded to have fallen is noticed by Capt. Hayward,* on whose vessel it fell whilst sailing from lat. 10° N. to 2° 560 N.; the distance from the nearest of the Cape Verd Islands being between 450 and 850 miles. Respecting the northern limit, the water for a great distance on both sides of C. Noon (in lat. 28° 450 ) is discoloured, owing in part, according to Lieut. Arlett,† to the quantities of falling dust. Hence the phænomenon has been observed over a space of at least 1600 miles of latitude. This dust has several times fallen on vessels when between 300 and 600 miles from the coast of Africa: it fell, in May 1840, on the Princess Louise‡ (in lat. 14° 210 N. and long. 35° 240 W.) when 1030 miles from Cape Verd, the nearest point of the continent, and therefore half-way between Cayenne in S. America and the dry country north of the Senegal in Africa. On the 16th of January (1833), when the Beagle was ten miles off the N.W. end of St. Jago, some very fine dust was found adhering to the under side of the horizontal wind-vane at the mast-head; it appeared to have been filtered by the gauze from the air, as the ship lay inclined to the wind. The wind had been for twenty-four hours previously E.N.E., and hence, from the position of the ship, the dust probably came from the coast of Africa. The atmosphere was so hazy that the visible horizon was only one mile distant. During our stay of three weeks at St. Jago (to February 8th) the wind was N.E., as is always the case during this time of the year; the atmosphere was often hazy, and very fine dust was almost constantly falling, so that the astronomical instruments were roughened and a little injured. The dust collected on the Beagle was excessively fine-grained, and of a reddish brown colour; it does not effervesce with acids; it easily fuses under the blowpipe into a black or gray bead. In 1838, from the 7th to the 10th of March, whilst Lieut. James4 in H. M. S. Spey was sailing, at the distance of from 330 to 380 miles from the continent, between lat. 21° 100 N., long. 22° 140 W., and lat. 17° 430 N., long. 25° 540 W., considerable quantities of dust fell on his vessel, four packets of which, together with a written communication, I owe to the

*

† ‡

Nautical Magazine, 1839, p. 364. [Hayward 1839.] The dust fell from the 9th to the 13th of February 1839, whilst sailing from (lat. 10° N., long. 29° 590 ) to (lat. 2° 560 N., long. 26° 300 W.). The wind on the 9th was E.N.E., on the 10th N.E. by E., and on the three succeeding days N.E. Geographical Journal, vol. vi. p. 296. “Survey of some of the Canary Islands and part of the coast of Africa, by Lieut. W. Arlett, R.N.” [Arlett 1836.] Edinburgh New Phil. Journal, vol. xxxii. p. 134. [Anon 1842.] The account is taken from Berghaus’ Almanack of the dust which fell on the Princess Louise on Jan. 14th and 15th, 1839, between (lat. 24° 200 N., long. 26° 420 W.) and (lat. 23° 050 N., and long. 28° 180 W.): and again in 1840 from the 6th to the 9th of May, whilst between (lat. 10° 290 N., long. 32° 190 W.) and (lat. 16° 440 N., long. 36° 370 W.). During the voyage of a vessel of the same name, in which Dr. Meyen was a passenger (Reise um Erde, Th. i. s. 54) on the 27th of October 1830, the sails were observed to be stained by a powder, which Dr. Meyen considered to be a minute Cryptogamic plant: the date would lead me to believe that in this case the phænomenon was different from that of the dust described in this paper. [Franz Julius Ferdinand Meyen (1804–40), Prussian botanist and physician and naturalist on board the Prinzess Louise, 1830–32. Meyen 1834.]

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kindness of Mr. Lyell.5 The dust which fell on the first day (or the 7th) was preceded by a thick haze, and it is coarser than that which fell on the succeeding days: it contains numerous irregular, transparent, variously coloured particles of stone about the 1/1000th of an inch square, with some few a little larger, and much fine matter. The fact of particles of this size having been brought at least 330 miles from the land is interesting, as bearing on the distribution of the sporules of cryptogamic6 |28| plants and the ovules of Infusoria. The dust which fell on the three succeeding days resembles in appearance and in its action under the blowpipe that collected by myself off St. Jago, and is so excessively fine, that Lieut. James was obliged to collect it with a sponge moistened with fresh water. As the wind continued nearly in the same direction during the four above-mentioned days, and the distance from the land was only a little increased after the first day, it would appear probable that the coarser dust was raised by a squall with which the breezes on this coast so often begin blowing. With respect to the direction of the wind during the falls of dust, in every instance where recorded it has been between N.E. and S.E.; generally between N.E. and E. In the case however given by the Rev. W. Clarke,* a hazy wind which had blown for some time from E. and S.E. first fell calm, and was succeeded for a few hours by a S.W. wind, and then returned strongly to the east; during this whole time dust fell. With respect to the time of year, the falls have always occurred in the months of January, February, March and April; but in the case of the Princess Louise in 1840, as late as on the 9th of May. In the one year of 1839, it has chanced that dust has been recorded as having fallen in the Atlantic (as may be seen in the references) on the 14th and 15th of January, and on the 2nd, 4th, 9th, 10th, 11th, 12th and 13th of February. I may add, that Baron Roussin,† during his survey of the north-western African coast, found, that whilst the wind keeps parallel to the shore, the haze and dust extend seaward only a short distance; but when during the above four specified months the harmattan7 blows from the N.E. and E.N.E., accompanied by tornados, the dust is blown far out, and is raised on high, so that stars and all other objects within 30° of the horizon are hidden. From the several recorded accounts‡ it appears that the quantity of dust which falls on vessels in the open Atlantic is considerable, and that the atmosphere is often rendered quite *

† ‡

Proceedings of the Geolog. Soc. vol. iv. p. 145. [William Branwhite Clarke (1798–1878), clergyman and geologist who emigrated to Australia in 1839. Clarke 1839.] The dust described by the Rev. W. Clarke fell February 2nd to the 4th, 1839, when between (lat. 21° 140 N., long. 25° 60 W.), and nearly (lat. 12° 360 N., long. 24° 130 W.). The direction of the wind has been already given in the paper; as it also has been, when the dust was collected by Lieut. James and myself. Mr. Clarke has since written a communication on the subject for the ‘Tasmanian Journal’ (vol. i. p. 321), to which I am indebted for two references. [Clarke 1842.] Nautical Magazine, 1838, p. 824. [Roussin 1826–7.] Nautical Magazine, 1837, p. 291. [Burnett 1837.] Mr. Burnett, on February 12th to 15th, in sailing from (lat. 4° 200 N., long. 23° 200 W.) to (lat. 8° N., long. 27° 200 W.), a distance of 300 miles, with the wind N.E., preceded by a S.E. squall which veered to E.S.E. and then to N.E., had the sails, rigging and mast covered with red dust. The dust began to fall as soon as the wind became N.E.: the atmosphere was very hazy. The nearest land was 600 miles distant. The same phænomenon was observed by Mr. Burnett in April 1836. Mr. Forbes gives an account (Sharon Turner’s S. Hist, of the World, p. 149) of dust which fell on a ship when 600 miles from the coast, between C. Verd and the R. Gambia: the wind all the previous night had been N.E. [Turner 1832–7.] In the Edinb. New Phil. Journal (vol. vii. p. 402) there is another account of dust which fell in considerable quantities on March 29th, 1821, in lat. 11° 30 N., when 300 miles from the nearest part of Africa. In Howard Malcolm’s Travels (vol. ii. p. 200) there is a similar account of dust which fell during several days in February on a ship north of the equator, when more than 1000 miles from the coast of Africa: the wind was N.E. [Malcolm 1839.]

1846. An account of the fine dust which often falls on vessels in the Atlantic ocean

195

hazy; but nearer to the African coast the quantity is still more considerable. Vessels have several times run on shore owing to the haziness of the air: and Horsburgh* recommends all vessels, for this reason, to avoid the passage between the Cape Verd Archipelago and the main-land. Roussin also, during his survey, was thus much impeded. Lieut. Arlett found the water so discoloured,† that the track left by his ship was visible for a long time; and he attributes this in part to the fine sand blown from the deserts, “with which everything on board soon becomes perfectly caked.” Professor Ehrenberg‡ has examined the dust collected by Lieut. James and myself; and he finds that it is in considerable part composed of Infusoria, including no less than sixtyseven different forms. These consist of 32 species of siliceous-shielded Polygastrica;8 of 34 forms of Phytolitharia, or the siliceous tissues of plants; and of one |29| Polythalamia. The little packet of dust collected by myself would not have filled a quarter of a tea-spoon, yet it contains seventeen forms. Professor Ehrenberg remarks, that as 37 species are common to several of the packets, the dust collected by myself, and on four successive days by Lieut. James, must certainly have come from the same quarter; yet mine was brought by a E.N.E. wind, and Lieut. James’s by a S.E. and E.S.E. wind. The Infusoria are all old known species, excepting one allied to a Hungarian fossil; and they are of freshwater origin with the exception of two (Grammatophora oceanica and Textilaria globulosa), which are certainly marine. Prof. Ehrenberg could not detect any of the soft parts of the Infusoria, as if they had been quickly dried up, and hence it would appear that they must have been caught up by the wind some time after having been dead. The greater number of the species are of wide or mundane distribution; four species are common to Senegambia and S. America, and two are peculiar to the latter country: moreover it is a very singular fact, that out of the many forms known to Professor Ehrenberg as characteristic of Africa, and more especially of the Sahara and Senegambian regions, none were found in the dust. From these facts one might at first doubt whether the dust came from Africa; but considering that it has invariably fallen with the wind between N.E. and S.E., that is, directly from the coast of Africa; that the first commencement of the haze has been seen to come on with these winds; that coarser particles have first fallen; that the dust and hazy atmosphere is more common near the African coast than further in the Atlantic; and lastly, that the months during which it falls coincide with those when the harmattan blows from the continent, and when it is known that clouds of dust and sand are raised by it, I think there can be no doubt that the dust which falls in the Atlantic does come from Africa. How to explain the enigma of the absence of characteristic African forms and of the presence of two species from S. America, I will not pretend to conjecture. Finally I may remark, that the circumstance of * †

‡

Horsburgh’s East Indian Directory, p. 11. [Horsburgh 1836.] In Tuckey’s Narrative of the Congo Expedition (p. 10), a discoloured sea and a hazy atmosphere are described on the 9th of April in lat. 22° N. and long. 19° 90 W., when 32 leagues from the main-land. [Tuckey 1818.] It may be worth here recording that Sir A. Burnes (Travels in Cabool, p. 223), in describing Khoten, a region of Upper Asia, adds, “it is said that its productiveness depends upon clouds of red dust, which always fall or are blown in this part of Asia.” But he thinks that the statement requires confirmation. [Burnes 1842.] These microscopic organized bodies have been described in the ‘Monatsberichten der Berlin Akad. der Wissens. Mai 1844; u. 27 Februar 1845.’ [Ehrenberg 1844 and 1845.] In the latter paper a full list of the names is given: the column marked St. Jago includes those collected by myself.

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1846. On the geology of the Falkland Islands

such quantities of dust being periodically blown, year after year, over so immense an area in the Atlantic Ocean, is interesting, as showing by how apparently inefficient a cause a widely extended deposit may be in process of formation; and this deposit, it appears from the researches of Prof. Ehrenberg, will in chief part consist of freshwater Polygastrica and of Phytolitharia.

1 2 3 4 5 6 7 8

See Journal of researches 2d ed., p. 5. Microscopic organisms, formerly also including siliceous skeletons of diatoms. Siliceous plant cells. Robert Bastard James, lieutenant and commander of the brig Spey from 1835. See CCD2: 77. Nonflowering plants. A dry and dusty West African trade wind which blows south from Sahara into the Gulf of Guinea between the end of November and the middle of March. Ciliated Protozoa, the Ciliata or Infusoria.

1846. On the geology of the Falkland Islands. By C. Darwin, Esq., F. R. S., F. G. S. [Read 25 March] Quarterly Journal of the Geological Society of London 2: 267–79. F1674 The Falkland Islands being a British colony, and the most southern point at which palæozoic fossils have hitherto been discovered, I am induced to lay a short account of the geological structure of these islands before the Society. They stretch from 51° to 52° 300 south, and extend about 130 miles in longitude. My examination was confined to the eastern island; but I have received, through the kindness of Captain Sulivan1 and Mr. Kent,2 numerous specimens from the western island, together with copious notes, sufficient to show the almost perfect uniformity of the whole group. |268| The low land consists of pale brown and bluish clay-slate, including subordinate layers of hard, yellowish, sometimes micaceous, sandstone: in the clay-slate organic remains are exceedingly rare, whilst in some of the layers of sandstone they are extremely numerous, the same species being generally grouped together. Messrs. Morris and Sharpe3 have kindly undertaken to describe these fossils in a separate notice: they consist (as I am informed by them) of three new species of Orthis, which have a Silurian character; three of Spirifer, which rather resemble Devonian forms, and approach closely to some of the Australian species described by Messrs. G. B. Sowerby and J. Morris;* one species both of Atrypa and Chonetes, the latter approaching very closely some of the varieties of C. sarcinulata of Europe; an Orbicula and an Avicula, the species not determinable; and lastly, a fragment of a Trilobite and numerous traces of Crinoidea, apparently related to the genus Actinocrinus. The concurrence of these several organic forms in this remote part of the southern ocean, giving to the aggregate so close a general resemblance with the palæozoic groups of *

Strzelecky’s Physical Description of New South Wales, &c., p. 279 et seq. [George Brettingham Sowerby (1788–1854), conchologist and artist. Strzelecki 1845.]

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the north, is an interesting circumstance. None however of the species appear absolutely identical with northern forms, or with the Silurian and Devonian mollusca described by M. A. d’Orbigny4 from the Bolivian Cordillera; these latter, eleven in number, are likewise all distinct from, though several are most closely related to, northern forms: two crustaceans however and a Graptolite appear to be identical with European species. With respect to the thirty-four or thirty-five palæozoic mollusca from Australia,* Mr. Morris has come to the conclusion that all are new, with the exception of one Terebratula: some of the species, moreover, have required the institution of new genera. Mr. Lonsdale5 has likewise found that the palæozoic Australian corals are almost all new species. Although the frequent and close general resemblance of the palæozoic fossils in very distant parts of the world is extremely remarkable, especially when we compare intra- and extra-tropical districts (as in the case of those described by M. d’Orbigny), yet I conceive that the opinion, that the further we look back in time, the more widely distributed the same species of shells were, must be greatly modified. We should bear in mind, that at the present day shells inhabiting seas, which instead of being divided by impassable barriers of land stretching north and south, are bordered by coasts running east and west or are interspersed with islands, often have enormous ranges: Mr. Cuming6 informs me, that he has upwards of a hundred species of shells from the eastern coast of Africa identical with those collected by himself at the Philippines and at the eastern coral-islands of the Pacific Ocean: now the distance from these islands to Eastern Africa is equal to that from pole to pole. Under similar circumstances Dr. Richardson7 has found that fishes have immense ranges. Moreover we should bear in mind, how few genera of shells are confined to particular regions of the world, that is, if we compare |269| the extra-tropical zones together and the inter-tropical zones together. Hence, from the distribution of existing mollusca, we ought not to feel surprised at the fossil species of the same period, in the most distant quarters of the same great zones, being sometimes identical, or differing only by specific characters. It is however right to add, that not only all the existing shells of the Falkland Islands and of Tierra del Fuego are specifically different from those of the northern hemisphere, but I think that they differ more palpably in form than do the palæozoic species from the same quarters: in this comparison however of the living shells, the littoral species are included; and these no doubt always show the effects of climate and other external influences more plainly than deep-water genera, such as probably were Spirifer and Orthis. The low clay-slate and sandstone districts of the Falkland Islands are broken by numerous ranges varying in height from a few hundred feet to between 2000 and 2500 feet, and all composed of stratified quartz. This rock varies from an arenaceous8 mixture to a pure white granulo-crystalline mass; it sometimes contains minute imperfect scales of mica arranged in parallel planes, and often small specks of a white substance, like earthy feldspar, exhaling an aluminous smell, but quite infusible under the blowpipe. Occasionally the rock assumes a curious brecciated appearance (apparently of concretionary origin), in which angular fragments of nearly pure quartz are imbedded in an opake siliceous paste, partly formed of the white earthy matter. I have observed these white and yellowish earthy specks in the quartz *

Strzelecky, ante cit., and the Appendix to C. Darwin’s Volcanic Islands.

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rocks of several other countries, and likewise in a calcareous rock in one of the Cape Verd islands, produced by the flowing of submarine lava over a recent shelly mass. The rock in this latter case is compact; and in a series of specimens, the gradual separation of the little specks of earthy matter, either through their mutual attraction, or more probably by the segregating influence of the stronger attraction of the atoms of carbonate of lime, could be most distinctly traced. There is good evidence that the quartz of the Falkland Islands has been softened by heat; and the analogy is so perfect between the little earthy specks in the two cases, that I believe they have been similarly produced. I nowhere actually saw the superposition of the clay-slate* on the quartz, but in several places on the sea-shore I traced the most gradual transitions between these two widely different formations. It was particularly curious to observe how insensibly the gently inclined planes of stratification in the quartz disappeared, and the highly inclined cleavage-laminæ of the clay-slate, extending in their usual course, appeared: it was impossible to point out where the stratification |270| ended and the cleavage commenced. From the manner in which the clay-slate and sandstone often come up on each side to the base of the quartz ranges, I have no doubt that this rock is a lower and more arenaceous formation metamorphosed. The many parallel ranges of quartz in the eastern part of the group extend east and west, but in the more westerly parts they run W.N.W. and E.S.E.: on the west side, however, of the great Sound between the two main islands, there is, according to Captain Sulivan, a fine range, 2000 feet in height, at right angles to the usual direction, and extending N.N.E. and S.S.W. The outline of the indented coast, and the position of the outlying islets, are in accordance with these axes of elevation. The cleavage-planes of the clay-slate strike almost invariably in the same direction with the quartz ranges: the laminæ are either vertical or highly inclined, generally at an angle above 50°, and dip either north or south, but most frequently to the south. The coincidence in direction (but not in dip) between the stratification of the quartz and the cleavage of the slate was strikingly seen at the western end of the Wickham Heights, which bend from their usual east and west line into a W. 35° N. course; and here at the foot of the hills I found the slate with an almost vertical cleavage striking in the unusual line of W. 30° to 40° N. I may add, that I found on the mainland of South America the cleavage-planes, with a high but variable dip, extending uniformly over extremely large areas, in the same direction as at the Falkland Islands, and in the same line with the prevailing axes of elevation, but intersected at right angles by other subordinate axes: I will not however here enlarge on this subject. The beds of sandstone included in the clay-slate in the lower and less troubled parts of the island are either horizontal, or dip in various directions, most commonly to the south, at angles between 10° and 20°. I repeatedly observed that the clay-slate had exactly the same highly inclined cleavage above and below these beds. Where this occurred, the sandstone generally broke, when struck, in the line of the cleavage, and transversely to its own planes of division, and the seams were full of fossil shells: Professor Sedgwick† has remarked the *

†

Captain Sulivan seems to have found on the western island subordinate beds of a conglomerate or coarse grauwacke. On this island there appear also to be traces of tertiary and boulder formations, corresponding with those of Tierra del Fuego. Captain Sulivan observed on the western island numerous basaltic dikes. Geological Transactions, 2nd Ser., vol. iii. p. 477.

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same fact in beds of limestone similarly situated; and it shows that the molecular arrangement even of these compact rocks has undergone some change. The strike of the cleavage, although coincident with the main lines of elevation, seems to have no reference to the minor flexures; and it preserves a remarkable uniformity whether the stratification of the clay-slate (distinguishable only by the intercalated beds of sandstone) has remained horizontal, or has been tilted at small angles in various directions. Captain Sulivan, who was so kind as to observe carefully the cleavage of the rocks, has however given me a drawing and minute description of some clay-slate beds, exposed in a cliff on the southern coast, in which the cleavage in some of the beds strikes perpendicularly without having been in the least influenced by the minor flexures; whilst in others |271| it is exactly at right angles to each flexure. The beds have been crushed into numerous successive folds, one of which is represented in the following woodcut.

A, D, F. Beds of clay-slate, with cleavage-laminæ perpendicular to the horizon. E and part of C. Similar beds, with the cleavage at right angles to every flexure. B and parts of C. Beds of imperfect, non-laminated clay-slate, with intercalated seams of sandstone represented by the dotted parts. F. Nucleus or core of clay-slate formed by the lateral crushing of the strata, about two feet high and one foot broad. These nuclei occur in almost all the folds.

Captain Sulivan states, that in some of the strata the cleavage “in every part, however much twisted, was perpendicular to the horizon;” in others “it was perpendicular to every curve.” I have never myself seen an instance of this structure, and I believe it is a new and interesting case. The remaining facts which I have to give refer entirely to the structure of the ranges, composed of quartz rock. In crossing the eastern island in a N.N.W. and S.S.E. direction, in a line intersecting the head of Berkeley Sound, we find north of it several low, parallel, interrupted, east and west ranges, with their strata all dipping a little west of south, at angles varying between 20° and 40°. South of Berkeley Sound the first range we come to is a short one, rising like all the others through the clay-slate formation: the strata near the summit of the

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principal hill are most regularly arched, with a curvature of 28° in the line of our imaginary section, and of from 14° to 16° in the line of the ridge: on the summit itself they are horizontal. A regular, flat-topped, oval dome (of which a section is here given) has thus been produced.

Dome-shaped hill of quartz, with strata dipping inwards at both the northern and southern base.

A valley having been hollowed out near the summit, a very curious scene of natural architecture is presented, which excited the utmost astonishment in the old voyager Dom Pernetti.9 At the northern and southern base of this hill, the strata, instead of being, as near the summit, dome-shaped, dip directly inwards at angles of 40° and 50°: I have little doubt, from what I saw in other places, that these strata form parts (as shown by the dotted lines in the section) of outwardly bulging |272| flexures, produced apparently by the weight of the superincumbent mass on the lower part when in a pasty state. Proceeding in our southern course, a second short east and west range is met with, formed of three principal hills, of which the first (960 feet high) is anticlinal with a broken summit. The second hill is also anticlinal, with horizontal strata on its broad summit, showing traces of curvature towards the edges: the inclination is rather greater on the south than on the north side. Between this second and third hill there is an anticlinal hillock, the strata on its south side dipping at an angle of 59°, and its summit folded as represented in the diagram.

Hillock of quartz with summit of axis-plane thrown over to the south.

We here see that the upper part of the axis-plane, to use a convenient term of the Professors Rogers, has been pushed over to the south. Throughout the third hill the strata at first appear all conformable, dipping from 50° to 55° N. by E.; but on examination I found a small portion, only fifty yards across in the line of the dip, inclined at an angle of 26° southward; and the tips of the adjoining beds were, as represented in the diagram, abruptly arched. Hence this hill

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has been formed by a mass of strata doubled on themselves, with the axis-plane thrown quite over to the south, as was the case with the upper part alone in the above-mentioned hillock.

Strata of quartz dipping 508 to 558 north, with a fold in the middle, only fifty yards across.

I have described this hill more particularly on account of a curious appearance presented by the arched parts of the strata. The arching has been so abrupt, that in some loose fragments, presenting a natural section, the radius of the curve is seen to be only seven feet. The end section of one such fragment, twelve feet in length, is accurately given in the following woodcut (No. 5), but allowance must be made for a little displacement from an open fissure crossing it.

Base of an arched fragment of quartz.

In this case the convex or outer and exposed surface is remarkably even and smooth; it is traversed in the line of the axis of curvature by numerous parallel veins, from the tenth to the twentieth of an inch in thickness, and from half an inch to two inches apart from each other: these often thin out at both ends, but where one thins out, another commences either a little above or below. The veins are partially filled by transverse threads of quartz very |273| imperfectly crystallized. The quartz-rock must obviously have been in a pasty condition, when it suffered without fracture such abrupt curvatures; and it was impossible to examine

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these veins without recognising in them the effects of the stretching, and in the fibres or imperfect crystals of quartz, the adhesive nature of the ductile mass.* This hill, as well as the two others in the range, show traces of a quâquâversal or dome-shaped stratification; and we can thus understand the occurrence of some few veins at right angles to those numerous ones in the line of the principal curvature; for there must have been some stretching in two directions. I may add that the arched strata in the more regularly domeshaped hill before described (No. 2), were intersected by a rectangular network of similar veins, almost equally numerous in both directions. All these greatly arched masses of quartz are very brittle. Referring once again to the fragment last figured (No. 5), it is seen to be divided by interrupted lines of stratification, concentric with the outer and convex and now accidentally exposed surface, but firmly united together. Captain Sulivan however found in another place innumerable similar fragments, in which the concentric layers were separate, so that the ground was strewed with gigantic semi-cylinders of quartz, like draining or ridge tiles; he measured one, represented in the diagram annexed (No. 6) and found it twenty feet in length, with a nearly regular diameter of twelve feet.

In this instance the edges or rim on both sides are of equal thickness; but in some other cases, whilst the rim on one side was two feet thick, on the other it thinned off to a knifeedge, evidently in consequence of the unequal pressure it had undergone. *

In a paper by M. Elie de Beaumont [Jean Baptiste Armand Louis Léonce Élie de Beaumont (1798–1874), French mining engineer and geologist. Élie de Beaumont 1839.] read before the Soc. Philomathique, May 1839 (L’Institut, 1839, p. 161), it is stated that M. Gaudin [Charles Théophile Gaudin (1822–66), Swiss palaeobotanist.] was able to draw out threads of melted quartz: M. Gaudin also found that quartz (differently from alumina) retained its viscidity for some time when cooling,—a fact to be borne in mind when we attempt to account for the remarkable flexures which nearly all the quartzose ranges in this island, and likewise in many other parts of the world, have undergone.

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Crossing a wide valley of slate and sandstone we come to the chief mountain-axis of the island, varying from 1500 to 2500 feet in height, and running nearly east and west. The strata on its northern flank dip northward; on the summit, which is from one to two miles broad, they are horizontal; on its southern side they are almost vertical with a southerly dip, and with their summits close to the horizontal beds abruptly arched; so that in this main range we have the same peculiar form of elevation, so common in all the smaller hills. At the southern base the strata were in some places folded in the |274| shape of upright arched gateways. I may mention that fifteen miles to the westward, at the foot of this same range, I found two hillocks of quartz only twenty yards apart, with the strata dipping at exactly the same angle of 40° to S.S.W., and therefore apparently quite conformable; but on close inspection the ends of the beds on the inner side of one hillock were seen to be arched in such a manner, as to show that they had been doubled on themselves, with the axis-plane inclined at an angle of 40°. A wide undulatory district of slate and sandstone extends southward of the main range; but on the coast, Captain Sulivan again found two east and west quartz ranges: one of these is transversely intersected by a creek (near Port FitzRoy), and two good sections, a hundred feet in height, are exposed. These are given in the following diagram on account of the complexity of the curvatures, almost resembling those produced by the mingling together of two viscid fluids; and because in crossing the country any one would be apt to think that the dome-formed hills had been produced by single impulses from below, whereas we now see that perpendicularly beneath one dome, another may lie hidden in the solid rock.*

I will not take up the time of the Society by giving any further details on the geology of these islands; nor would the foregoing account have been worth communicating, had it not been for the interest which is justly taken in ancient fossils coming from a very distant quarter of the world.

*

It is singular in how many points the old quartz-rock of Anglesea, as described by Professor Henslow in his admirable paper in the Cambridge Phil. Trans. (vol. i. p. 359), agrees with that of the Falkland Islands. The quartz of Anglesea is granule-crystalline, and contains white earthy spots and a little mica; it passes insensibly into an overlying chloritic schist, and this again into clay-slate. The strata have been in a pasty condition, and have been singularly curved: they strike in the same direction with the laminæ of the overlying slates, but their average inclination is less.

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Bartholemew James Sulivan (1810–90), second Lieutenant on second voyage of the Beagle with CD. William Kent, joined Beagle in 1833 as Assistant Surgeon on return voyage. John Morris (1810–86) and Daniel Sharpe (1806–56), geologists. Morris and Sharpe 1846. Orbigny [1834]–47. William Lonsdale (1794–1871), soldier, geologist and Curator and Librarian of the Geological Society of London 1829–42. Hugh Cuming (1791–1865), naturalist and traveller who collected shells and orchids in Chile and the Pacific. John Richardson (1787–1865), ships’ surgeon, naturalist and arctic explorer. Richardson 1845. Derived from or containing sand. Pernety 1770.

[Darwin, C. R.] 1847. [Review of] A natural history of the Mammalia. [vol. 1, Marsupialia] By G. R. Waterhouse, Esq., of the British Museum. Illustrated with engravings on wood and coloured plates. London, H. Baillière. Annals and Magazine of Natural History 19 (January): 53–6. F1675 The first volume of this excellent work,1 in which every species in the class Mammalia will be described in detail, is now completed. The author is already favourably known to the public by various monographs, and by papers in this Journal, on the Rodentia, Marsupiata and other animals. His former connexion with the Zoological Society and his present position in the British Museum (where he is |54| at present chiefly employed on fossil Mammalia),—his extensive acquaintance with the works of foreign naturalists, as shown by the numerous references in this publication,—together with several visits undertaken solely from his love of science to the museums on the continent, eminently fit him for the great work here commenced. We use this expression advisedly, for it must not be supposed that we have here merely a compilation; original descriptions, and measurements generally taken from more than one specimen, are in the majority of cases given. The dental and osteological details are described with particular care, and are illustrated by distinct and careful plates: in the precision of these details, we imagine we see the effects of Mr. Waterhouse’s long and ardent attachment to entomology. Although the work is not a compilation, the author has not neglected any source of information; and in this first volume, which is confined to the Marsupiata, he is much indebted to Mr. Gould’s admirable labours in Australia. Mr. Waterhouse however often differs from Mr. Gould with respect to specific characters, and we rejoice to see no signs of that rage to create new species, so prevalent amongst zoologists. A distinguishing feature in this work is the notice of all fossil species, interpolated in their proper places; hence, when the whole is completed, we shall have a comprehensive view of the entire class of Mammalia, as far as known; and the accident of extinction will not remove from the series, as is too often the case in systematic works, allied or intermediate forms. Many curious and original remarks are interspersed on the affinities of the various genera and families; but we find no trace of those fanciful speculations on analogies—such as

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between a mouse’s nose and a snipe’s beak, or between oxen and poultry—which we fear must have lowered us in the estimation of continental naturalists. In reference to affinities, we must express our regret that the Marsupiata were not ranked, in conformity with Prof. Owen’s views, as a sub-class distinct from the placental mammifers. Whether we view classification as a mere contrivance to convey much information by a single word, or as something more than a memoria technica, and as connected with the laws of creation, we cannot doubt that where such important differences in the generative and cerebral systems, as distinguish the Marsupiata from the Placentata, run through two series of animals, they ought to be arranged under heads of equal value. We are not convinced by the ingenious remarks on this subject given at p. 17; we cannot admit that numerical differences in the number of the species in two groups, or their geographical distribution, or a somewhat hypothetical statement that the amount of difference is greatest amongst the lower forms in each class, ought to be taken into account in a system of classification; we believe that our best botanists, who may well serve as guides on this subject, eschew such considerations, and confine themselves to the strict rule of difference in structure. Should this rule be disregarded, some naturalists would admit habits (useful as they undoubtedly are)—some would admit analogies, or, as well expressed by Lamarck, adaptations in widely different |55| beings to similar external conditions,—some would admit the supposed order of the appearance of organic beings (as has been suggested) on the surface of the earth, as aids or bases of classification;—the result would be, that no two naturalists would agree in the same conclusion, and our system, instead of becoming a solid and simple edifice, would be a labyrinth of blind passages. An admirable feature in Mr. Waterhouse’s work is the great attention paid to Geographical distribution, that noble subject of which we as yet but dimly see the full bearing. The following remarks (p. 537) give us an excellent summary on the distribution of the Mammalia on the Australian continent:— “Australia may be conveniently divided into five principal divisions or districts, of which the east, west, north and south portions of the main land will each form one province, and Van Diemen’s Land2 the fifth. Of these provinces, the northern one has the greatest number of species peculiar to it, since out of ten species discovered in that part of Australia, eight are not found elsewhere. The Marsupiata of the eastern district are for the most part distinct from those of the opposite side of the continent, there being but eight species, out of upwards of sixty inhabiting the two provinces, which are found in both. But if the three districts mentioned are characterized by the few species which they have in common, South Australia must be characterized by an opposite quality, that of having a comparatively large proportion of species identical with those of other districts; indeed I know of but four species which are peculiar to this district: it possesses sixteen species in common with Western Australia, and fifteen in common with Eastern Australia. Western Australia possesses one genus (Tarsipes)3 which is peculiar to it, and one sub-genus (Macrotis);4 none of the other districts of continental Australia possess any genera which are not found elsewhere. About half of the species found in Van Diemen’s Land are peculiar to that island—in fact, nine out of twenty: of the remainder, the greater portion are found on the eastern part of the main land. This island, moreover, possesses one genus (Thylacinus)5 and one sub-genus (Sarcophilus)6 which are now peculiar to it. Examples of both these sections have, however, been found in a fossil state on the main land.”

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Speaking strictly we have here four divisions, for South Australia does not appear from these remarks, zoologically considered, to deserve to be ranked as a subdivision. New Guinea, however, and the adjacent islands form a well-marked fifth subdivision, and an interesting table is given (at p. 3) of the ranges of the quadrupeds inhabiting them. The fact of South Australia possessing only few peculiar species, it having apparently been colonized from the eastern and western coasts, is very interesting; for we believe that Mr. Robert Brown7 has shown that nearly the same remark is applicable to the plants; and Mr. Gould finds that most of the birds from these opposite shores, though closely allied, are distinct. Considering these facts, together with the presence in South Australia of upraised modern tertiary deposits and of extinct volcanos, it seems |56| probable that the eastern and western shores once formed two islands, separated from each other by a shallow sea, with their inhabitants generically though not specifically related, exactly as are those of New Guinea and Northern Australia, and that within a geologically recent period a series of upheavals converted the intermediate sea into those desert plains which are now known to stretch from the southern coast far northward, and which then became colonized from the regions to the east and west. We will only further point out an interesting table (p. 536) showing that in South America, Brazil is the metropolis of the Didelphidæ,8 a family which, as Mr. Waterhouse remarks, curiously replaces in that continent the Insectivora9 of the Old World. Most of the genera are illustrated by elegant and spirited copperplates; there are also many woodcuts; some few however of these latter are rather unfortunate works of art. The plates are printed on excellent paper, and the whole work is got up in a style creditable to the publisher. The Marsupiata, though highly interesting in their structure and affinities, yet are less so in their habits than the higher mammalia; but from some scattered notices we clearly see that this amusing part of the subject will not be neglected. To the professed naturalist we believe that this work will be almost indispensable; but we also strongly recommend it to those who do not come under this class, but yet are interested in the wide field of nature. We do not doubt that Mr. Waterhouse is conferring by this publication a real service on natural science; we therefore trust to his continued perseverance, and we heartily wish him all success.

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Waterhouse 1846. The second volume (On Rodentia, or gnawing animals) appeared in 1848. George Robert Waterhouse (1810–88), mammalogist and entomologist. Keeper of Mineralogy and Geology at the British Museum (Natural History); a friend of CD’s and often at Down House. Waterhouse wrote Mammalia 1838–9. See CCD3: 374. Tasmania. Mouselike Australian marsupial, the honey possum. A marsupial genus of rabbit-eared bandicoots or bilbies. Tasmanian wolf. Tasmanian devil. Robert Brown (1773–1858), botanist. First Keeper of Botany at British Museum. American opossums. Hedgehogs, shrews, moles etc.

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1847. Salt. Gardeners’ Chronicle and Agricultural Gazette no. 10 (6 March): 157–8. F1676 Your correspondent “W. B. N”1 must, I think, have seen salt from other salinas than those described by me;2 probably (as I infer from his statement that the salt is brought into Buenos Ayres in ox-waggons), from the salinas north of S. Ventana. The salt from the Rio Negro, from the S. Chiquitas and from San Julian, instead of being an “amorphous mass,” yielding “a soft powder,” is coarsely crystallized, some of the cubes being even 3 or 4 inches square. Instead of being |158| mixed with much earth, the salt presents an expanse as white as newly fallen snow, which, viewed from a distance, as I well remember to my cost, might readily be mistaken for a lake. Your correspondent seems to think that by the term purity, I imply freedom from dirt, but in my work I explain that I mean, “the absence of those other saline bodies found in all sea-water,”— a remarkable fact, which I state after the careful analysis of Mr. T. Reeks3 of the Museum of Econom. Geology. The salt consists entirely of chloride of sodium, with the exception of only 0.26 of sulphate of lime, and 0.22 of earthy matter. This fact having been ascertained, and the mass being well crystallised, it still appears to me that its lesser value for curing meat is probably owing to its purity, in the sense in which I have perhaps inappropriately used the term, that is, to the absence of those other saline substances found in sea-salt. I should not, however, have ventured on this opinion, had not Prof. Johnston4 come to the conclusion “that those salts answer best for preserving cheese which contain most of the deliquescent chlorides.”5 I must yet think that the experiment of adding some of the muriates of lime and magnesia to the salt from the Rio Negro, would be very well worth trial by the owners of the Saladeros near Buenos Ayres.—C. Darwin.

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4 5

W. B. N. 1847. See Journal of researches 2d ed., pp. 65–7. Trenham Reeks (1823/4–79), mineralogist. For Reeks’ analysis of some of CD’s mineral specimens from the Beagle voyage see Journal of researches 2d ed., p. 66 and CCD3, letter to T. Reeks [before 8 February 1845], and letter from T. Reeks, 8 February 1845. James Finlay Weir Johnston (1796–1855), reader in chemistry and mineralogy at Durham University and the practical chemist of the Agricultural Chemical Association. A paraphrase of comments printed in Report of the Agricultural Chemical Association. Gardeners’ Chronicle and Agricultural Gazette no. 6 (8 February 1845): 93.

1847. Copy of Memorial to the First Lord of the Treasury [Lord John Russell], respecting the Management of the British Museum. Parliamentary Papers, Accounts and Papers 1847, paper number (268), vol. XXXIV.253 (13 April): 1–3. F1831 To the Right Honourable Lord John Russell, M. P., First Lord of the Treasury, &c. &c.1 We, the undersigned, members of the British Society for the Advancement of Science, and of various scientific societies, respectfully submit to the consideration of your Lordship, that a strong feeling pervades the naturalists of our country, that the promotion of the science of

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1847. Copy of Memorial to the First Lord of the Treasury [Lord John Russell]

Natural History is very inadequately provided for by the present constitution of the Board of Trustees of the British Museum. So long as that institution consisted only of a library, with limited collections of antiquities and natural curiosities, it was easily managed by a body consisting of public functionaries, men of rank and general attainments, and the representatives of the chief donors of the Museum. When, however, the establishment was so enlarged as to become a national deposit of the productions of nature, both recent and fossil, together with vast additions to the books, manuscripts, prints, statues, &c., supplemental trustees were elected to aid in the direction. We rejoice that eminent men of letters were thus associated in the Trust; but even so amended, the Board, with the best intentions, we believe, has found it very difficult satisfactorily to perform the numerous and various duties devolving upon it; for although the “ex officio” Trustees, the Presidents of the Royal Society and of the College of Physicians, are necessarily persons of weight in science; and although we gratefully witnessed the election of the eminent astronomer, Sir John Herschel, we would earnestly represent to your Lordship, that the qualifications of these gifted individuals do not necessarily include an interest in, or the ability to judge of, many of those measures which may best promote Natural History; and, consequently, that there is no effective provision (in the absence of other men of science) for the proper guidance of the Natural History department, or for having at the Board, trustees who can explain to their associates the desiderata of naturalists, and estimate the value of new specimens, either offered to or purchased by the nation. Fully acknowledging, that in their accomplishments and high characters the present Trustees offer the best sureties for the satisfactory execution of any duties connected with their own pursuits, we still think that, with the best disposition (and they have already done much good service) these distinguished men are unable adequately to direct the vast and rapidly increasing Natural History departments of the Museum; and we can even well suppose that they would themselves be happy to be relieved from the heavy responsibility which must be attached to the application of the large sum annually voted by Parliament for the support of natural science. Now, in the event of a knowledge of Natural History being in future recognized among the grounds for election to the Trusteeship of the British Museum, we should have reason to anticipate that the sum allotted to this subject would be applied so efficiently and regularly to its extension and improvement, as would |2| best secure the progress of science, and yield most interest and instruction to the public. Deeply impressed with these sentiments, we beg to suggest, for the consideration of your Lordship, that steps should be taken to effect such an improvement in the constitution of the Trust, as shall render the management of the Natural History departments of the British Museum, as far as possible, independent of the other divisions; and on this point we would beg to refer your Lordship to the original plan of Sir Hans Sloane.2 In offering this suggestion, we do not contemplate a separation of the Natural History collections from the other departments of the British Museum, as we well know that the cultivation of natural science cannot be efficiently carried on without reference to an extensive library.

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What we chiefly desire to see is, the formation of such a responsible system of management as may satisfy the public and ourselves, that in this great national establishment, the interests of all branches of natural science will be thoroughly protected and advanced, and that the halls devoted to it shall be so enriched with well selected and well classified objects of contemplation and comparison, as shall not merely gratify the curiosity and excite the wonder of the multitude, but shall prove of real use to the researches of the student and the man of science. (signed) C. Darwin, F. R. S. F. G. S. &c. [The other 56 names are omitted.]

1

Presented on 10 March 1847. See CCD13: 368–71. A Royal Commission was appointed as a result of this petition in June 1847. Its recommendations were not followed and no serious reorganisation took place until the natural history collections were moved in 1880 to South Kensington in the new British Museum (Natural History) building. 2 Hans Sloane (1660–1753), physician and collector who bequeathed his collections to the nation in 1753, leading to the foundation of the British Museum in 1754.

1848. On the transportal of erratic boulders from a lower to a higher level. By C. Darwin, Esq., F. R. S., F. G. S. [Read 19 April] Quarterly Journal of the Geological Society of London 4: 315–23. F16771 It will, I think, be generally admitted that the most valid objection which has been advanced against the theory of the transportal of erratic boulders by floating ice, lies in the fact of their having not unfrequently been carried from a lower to a higher level. Mr. Hopkins,* indeed, referring to certain boulders of a peculiar conglomerate described by Prof. Phillips, considers this fact as affording an absolute proof of the diluvial theory, since, he adds, “it is evident that no floating ice could possibly transport a boulder from the depths of the vale of Eden over the heights of Stainmoor.” Prof. Hitchcock2 has several times alluded to similar cases in North America as offering a very great difficulty. The first instance recorded, as far as I know, of the transportal of boulders from a lower to a higher level, is by Prof. Phillips,† who in 1829 described numerous large blocks of grauwacke not far from Kirby Lonsdale, scattered over the mountain limestone from a height of 50 to 100 feet above the parent rock, which lies immediately beneath. He adds, “Further on, to an elevation of 150 feet, the blocks are still numerous, and they may be seen, by ascending one ledge after another, almost to the top of the Fell,3 500 feet above their original position. They appear,” he continues, “to have been driven up at a particular place by a current towards the north, and afterwards carried along the surface of the limestone in a narrow track toward the summit of the Fell.” The conglomerate alluded to by Mr. Hopkins has been transported from the bottom of the valley of the Eden, where the rock lies in situ at the height of 500 feet above the level of the sea, to and over the pass of Stainmoor at the * †

Journal of the Geol. Soc. vol. iv. p. 98. [Hopkins 1848.] Transactions of the Geol. Soc. vol. iii. (second series) p. 13. [J. Phillips 1835.]

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height of 1400 feet:* therefore the boulders now lie 900 feet above their original position. In 1838 I observed many boulders of granite strewed on Ben Erin on the western side of Glen Roy,† up to the height of 2200 feet above the sea; the granite resembled in character that seen in situ at the head of the Spey, and which, in Macculloch’s Geological Map,4 is likewise the nearest district of granite: if, as I believe, the boulders came from this place, they must have been carried up at least 900 feet. Mr. Maclaren‡ has described (1839) numerous blocks of sandstone on the higher parts of Arthur’s Seat, “400 feet above any spot where sandstone now exists in situ.” Quite recently Mr. D. Milne§ has noticed other boulders on the same hill, belonging to the coal series, and remarks “that there is no place in the neighbourhood from which these blocks could have come which is not at least 200 feet below their level.” In the Isle of Man, the Rev. J. G. Cumming5 has observed with great care a |316| striking case, and has most kindly communicated to me the details, which will immediately appear in his work:** near South Barrule there is a hillock formed of granite, quite different in nature from any other rock in the island; this mass of granite is about three-fourths of a mile square, and is 757 feet above the level of the sea; from this point the boulders are thickly dispersed to the south-west, and they can be continuously followed up to a height of 788 feet above the summit of the present boss. Mr. R. Mallet6 informs me that facts of a similar nature have been observed in Ireland. More striking cases occur in the United States, in New England, in New York, and in northern Pennsylvania. Prof. Hitchcock observes,†† that the Silurian rocks of New York and the quartz in the valleys of western Massachusetts have undoubtedly been carried over and left upon the Hoosac and Taconic mountains, at a height of “upwards of one thousand or two thousand feet.” Lastly, I may mention the analogous case of the chalk-flints, associated with boulders of various kinds, observed by the Dean of Westminster7 and myself on Moel Tryfan, at the height of 1392 feet above the level of the sea, and which (as well as the chalk-flints at the intermediate point of the Isle of Man)‡‡ there is good reason to believe must have come from Ireland, and therefore, at least in the case of North Wales, from a considerably lower level. The first point to consider is whether, in these several instances, the boulders have really come from a lower level, or whether they may not (and I am indebted to Sir H. De la Beche8 for this caution) have been derived from strata now entirely denuded, but which formerly extended up to the same level with the boulders. Or secondly, whether the boulders, after having been deposited, may not have been raised by an unequal elevatory movement above their parent district, or the district itself have been depressed by subsidence below them. With respect to the former supposed greater extension and subsequent denudation of the parent rock,—in such cases as those near Edinburgh it is possible that this may be sufficient * † ‡ §

** †† ‡‡

Treatise on Geology (Lardner’s Encyclop.), by John Phillips, vol. i. p. 270. Philosophical Transactions, 1839, p. 69. [Darwin 1839, F1653 (p. 50).] Geology of Fife, &c. p. 47. [Maclaren 1839.] Edinburgh New Philosophical Journal, vol. xlii. p. 167. [David Milne-Home [or David Milne] (1805–90), Scottish advocate and geologist. Milne 1847.] The Isle of Man, its History, &c., by the Rev. J. G. Cumming. [Cumming 1848.] Geology of Massachusetts, vol. i. (Postscript, p. 5a), [Hitchcock 1841.] and Address to Association of American Geologists, 1841. [Rogers 1844.] The Rev. J. G. Cumming in Transactions of British Association, 1845, p. 61. [Cumming 1846.]

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to account for the phænomenon. Where the boulders are of granite, as at Glen Roy and the Isle of Man, this view implies that a mass of that rock has been worn down, equalling in thickness the difference in level between the existing mass in situ and the boulders: in North America, where the boulders lie from 1500 to 2000 feet above their source, the denudation on this view must have been immense, and it must all have been effected within the glacial period, as the low country is covered with boulders; this likewise is the case with the boss of granite in the Isle of Man. Can it be supposed with any probability that the chalk-formation formerly extended in Ireland up to a height of nearly 1400 feet? In the case of the boulders described by Prof. Phillips, I am assured by him that the above view is quite inadmissible; and he has pointed out to me conclusive reasons, but which, considering |317| his high authority, I do not consider it necessary to give in detail; I will only mention that the grauwacke was planed down level, before the thick mass of mountain-limestone on the surface of which the boulders lie was deposited on it, and that at a short distance the grauwacke is quite cut off by the Craven fault:9 the conglomerate beds, whence the boulders at a height of 900 feet on Stainmoor were derived, are horizontal. With respect to subsequent unequal elevation having caused the boulders now to lie above their parent rocks, the simple fact of the number of points, irregularly placed both in Great Britain (namely, in northern and central Scotland, in the Lake district, North Wales, Isle of Man and Ireland,) and likewise in the United States, appears to me to render this view extremely improbable; for on such a view it must be admitted that in Great Britain and America several great mountains and mountain-chains have been formed so lately as during the glacial period, and this is a proposition to which few geologists will be inclined to assent. Moreover, in the case of Stainmoor, it is known that its crest now holds, one part with another, the same relative level as it did during the glacial period, for the boulders have crossed it only in one notch or gap, which is now the lowest part; and certain chains of hills which would at present intercept boulders coming from one quarter likewise did so at the glacial epoch. In the Isle of Man the parent granite and the boulders which lie 788 feet above it are scarcely more than two miles apart, and in the intermediate tract, thickly covered with the boulders, Mr. Cumming has in vain searched for evidence of a fault. In the Lake district there is, I think, conclusive evidence that unequal elevation is not the true explanation, for the boulders there lie so close to the rocks in situ that there would necessarily be, if the boulders had been subsequently upraised, a fault or abrupt flexure, in one case of 900 and in the other of 500 feet. Hence we must conclude, in accordance with the views of the several authors who have described the above cases, that the boulders have really been drifted nearly as many feet upwards (that is, making in almost every instance some allowance for the subsequent denudation of the parent rock) as they now lie above their original source. Those who believe in the powerful agency of ice in moving boulders will probably at first conclude that icebergs have in some manner transported them from a lower to a higher level. But the most obvious method by which fragments of rock can get on icebergs is by their having first fallen from the surrounding precipices on glaciers entering the sea, and therefore they must have come from a higher to a lower level. It seems impossible, owing to the

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temperature of the water, that at any considerable depth, boulders could be frozen into the bottom of icebergs; and even if at lesser depths they did become so frozen* or mechanically wedged in, and if by the icebergs being overturned they were saved from being soon thawed out, yet they could be deposited above their former level only by so much as |318| the ice under water had decreased in thickness in the interval of the boulders having been caught up and dropped. In any case the notion of icebergs having, in the States of New York, New England, and northern Pennsylvania, lifted up numerous boulders from a depth of between 1000 and 2000 feet, is quite inadmissable. In my paper on the Boulders of the Southern hemisphere, read before this Society,† I pointed out that there were two methods, essentially distinct both in the requisite climate and in the results produced, by which fragments of rock are transported; namely, by icebergs and by coast-ice. Icebergs now transport fragments of rock on the west coast of South America, in the latitude of the central parts of Europe, under a temperate climate where the sea, even in protected bays, is never frozen. On the other hand, in the northern parts of the United States and in the Gulf of Bothnia, where the climate is excessive, but yet under a latitude where glaciers never descend to the level of the sea, fragments of rock are annually enclosed by the freezing of the coast-water, and are thus transported. In the polar regions both actions concur. Icebergs will transport such fragments of rock as fall on the parent glaciers, and these are generally quite angular. From the vast size of the bergs, the fragments will often be transported to great distances, and when deposited, it must be in deep water, and therefore (as well as from the original descending movement of the glacier) at a much lower level than the parent rock: when once dropped, they will probably never again be moved by ice. On the other hand, coast-ice will transport whatever fragments of rock or pebbles lie on or near the shore. These fragments, from being repeatedly caught in the ice and stranded with violence, and from being every summer exposed to common littoral action, will generally be much worn; and from being driven over rocky shoals, probably often scored. From the ice not being thick, they will, if not drifted out to sea, be landed in shallow places, and from the packing of the ice be sometimes driven high up the beach, or even left perched on ledges of rock. By this agency boulders will probably not be carried to such great distances as by icebergs, and the limit of their transportal will perhaps be more defined. In South America there is a considerable difference in the state of the boulders in Tierra del Fuego, where a large proportion are much rounded, and on the plains of Patagonia and in Chiloe further from the pole, where the boulders are larger and quite angular. I attributed the presence of these latter to the exclusive action of icebergs; whilst in Tierra del Fuego coast-ice appears formerly to have come into play. On Moel Tryfan‡ the wellrounded fragments of chalk-flints were in all probability transported by coast-ice: though I cannot doubt, from the extraordinary manner in which the laminæ of the slate rocks have there been shattered, that icebergs have likewise been driven against them when under water; * † ‡

See some excellent remarks on this subject in Sir H. De la Beche’s Anniversary Address for 1848, p. 68 et seq. [De la Beche 1848.] Transactions of the Geol. Soc. vol. vi. (second series) p. 430. [Darwin 1841, F1657 (p. 128).] London Philosophical Journal, vol. xxi. p. 186. [Darwin 1842, F1660 (p. 140).]

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so that both actions seem there to have concurred. Some other distinguishing characters between the action of coast-ice and of icebergs will presently be pointed |319| out; and it is by coast-ice, as I believe, that boulders have been transported from a lower to a higher level. To take the case of North America: Mr. Lyell* has shown, from an independent train of reasoning, that this country during the glacial period slowly subsided to a considerable amount: several American geologists have come to a similar conclusion, and they believe that the subsidence amounted to two or three thousand feet, or even more. Let us suppose a sinking movement to be now going on in the estuary of the St. Lawrence or on the coast of Labrador, where we know, from the observations of Lieut. Brown and Capt. Bayfield,10 as given by Mr. Lyell† (and illustrated by striking sketches), that annually an enormous number of boulders, both on and near the coast, are frozen into the coast-ice and transported to shorter or greater distances; can we doubt, that if during the year the land sunk a few inches or feet, the boulders, whilst actually frozen in or when refrozen during the ensuing winter, would be lifted up and landed so many inches or feet higher up on the coast? Capt. Bayfield, as stated by Mr. Lyell,‡ saw masses of rock, “carried by ice through the straits of Belle Isle, between Newfoundland and the continent, which he conceives may have travelled in the course of years from Baffin’s Bay.” Now if during this probably long course of years,—for the boulders seem generally to be transported only a short distance each winter,—the land had subsided one or two hundred feet, is it not almost certain that they would have been landed so many feet higher up with respect to their former level, in the same manner as would have happened with so much drift timber? It is indeed paradoxical thus to speak of the boulders having been carried up, whilst the land has gone down; for, in fact, the boulders are merely kept by the floating ice at the same level, whilst the land sinks. No doubt during this process some boulders would be dropped in water too deep to allow of their being refrozen, and they would be thus left behind. Scarcely any form of land would prevent the boulders from being annually landed on a temporary resting-place: even a line of perpendicular cliff, if not of very great length, would probably only cause the tidal currents to drift the coast-ice further onwards; a few more boulders, perhaps, being dropped there than elsewhere. I can see only one difficulty of any weight to this view, namely, that the boulders would be ground down into mud and destroyed from having been stranded such innumerable times, as must have happened with those which were kept up to the same absolute level during a sinking of the land of many hundred feet. On an exposed coast, where the breakers had power to dash pebbles against the boulders, I have no doubt that this would take place, more especially with boulders small enough to be themselves rolled over. But on a broken coast, amongst islands and in bays, I do not believe that this would happen. We may infer from the fact of scored rocks having been observed both in Scotland and in North Wales, dipping |320| under the surface of lakes, in a quite unaltered condition, that the action of simple water, and of such little waves as lakes can produce, even when prolonged from the glacial period to the present day, is absolutely as nothing; and in sheltered bays, the force * †

Travels in North America, vol. i. p. 99, and vol. ii. p. 48. [Lyell 1845.] ‡ Principles of Geology, 7th edit. p. 222. [Lyell 1847.] Ibid. p. 231.

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of the waves is not very much greater than in lakes. Moreover, in South America I have seen many boulders lying on sea-beaches, exposed to the wash of rather open channels, and which, so far from having been destroyed, yet retained their angles perfect. Nevertheless it might certainly be expected that boulders which had thus been buoyed up by coast-ice during long-continued ages would be well-rounded. According to Prof. H. D. Rogers, this is the case with the majority of the boulders in North America: those at Glen Roy were rounded, but they were composed of granite subject to disintegration; this likewise is the case with those in the Isle of Man: Mr. Cumming however informs me that the boulders, with some marked exceptions, “diminish in number and size the further we proceed” from the granitic boss. The boulders on Arthur’s Seat,11 judging from the remarks of Messrs. Maclaren and Milne,12 are rounded. Those near Kirby Lonsdale, which now lie, according to Prof. Phillips, 500 feet above their parent rock, are not rounded; but they are composed of slate, a rock very little liable to be rounded, and they appear to lie in a sort of train up a valley surrounded by mountains, which must formerly have been a well-protected bay. It would be interesting to ascertain whether those boulders which now stand highest above the parent rock are more worn than those at a lower level, which latter I believe to have been dropped during the long-continued buoying-up process. We have seen that, according to Mr. Lyell, the northern parts of the United States did actually subside during the glacial period. I am not aware that anyone has attempted to show that Great Britain was similarly affected during this same period. The following considerations, however, appear to me to render it in some degree probable: in Staffordshire there are many great and perfectly angular boulders of northern rocks, which almost every geologist believes were transported on icebergs, now lying at the height of above 800 feet above the sea; and on Moel Tryfan, at a height of nearly 1400 feet, there are stratified beds of the glacial epoch (as known by the included shells discovered by Mr. Trimmer),13 which beds, after careful examination, I cannot doubt were deposited in the ordinary manner under the sea. On the other hand, the character of the miocene formations, on the east coast of England, belonging to an epoch just antecedent to the glacial, lead to the conclusion that the land then did not hold a level widely different from the present one: if so, unless we suppose a great inequality in the changes of level between the east and west coasts of England, the land must have sunk after the miocene age to allow of the deposition of the glacial deposits at the heights above specified. This conclusion accords perfectly with Professor E. Forbes’s statement,* that all the organic remains seen by him, from the glacial formation, indicate a depth of less than 25 |321| fathoms. As far then as these considerations can be at all trusted, we are, according to the view given in this paper, in a position to explain the transportal of the boulders from a lower to a higher level, in Great Britain as well as in the United States. I will make only one other remark on this head: though I believe that Great Britain subsided during the glacial period, yet I conceive it must also have subsequently attained during this same prolonged period a considerable portion of its present height. I infer this from the

*

Memoirs of the Geological Survey, p. 376. [Forbes 1846.]

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plain marks of true glacier action, low down the valleys in North Wales, within 300 feet of the present level of the sea.* A second objection of apparently considerable weight has been advanced against the theory of floating ice; namely, that in some instances the blocks decrease very regularly in size in proceeding from their source. Prof. H. D. Rogers† says that this is markedly the case in going southward in the United States. According to Mr. Hopkins‡ it is also the case in the Lake district; “the blocks becoming smaller as we approach the coast of Yorkshire, till they degenerate into pebbles in the more remote localities, in which the Cumbrian rocks can be identified.” He adds, “These facts are strongly in favour of those views which would refer the transport of these masses to diluvial currents.” This sorting of the boulders does not always hold good: on the plains of Patagonia the two largest boulders which I saw were near the outskirts of the deposit. Sir R. Murchison also remarks on the vast size of the many boulders in the south-east parts of Shropshire, near the southern limit of his northern drift, though he elsewhere states that the boulders generally decrease in size in going from north to south. In these cases, if we look at the boulders as having all been transported on icebergs, there certainly appears no reason why they should have been dropped from such immense masses of ice, with any approach to order according to their size and to their distance from their source. But this does not hold good with boulders transported in sheets and fragments of coast-ice: here the buoying agent is not of disproportionate power to its burthen; as the ice decays, the heaviest fragments would naturally be apt to drop out first; and it would appear from the accounts given to us, that the largest boulders during some winters escape being moved at all, whilst the smaller ones are drifting onwards. Moreover, the boulders (and great stress may probably be laid on this point) which had travelled furthest, would, from having been repeatedly stranded, and necessarily so every summer, be most worn, and therefore would be smaller than those which had travelled to a shorter distance. I have shown, in my volume on South America, that the sea has |322| the power by some means of sorting the pebbles which lie at the bottom, their size decreasing with surprising regularity, even till they pass into sand, with the increasing depth.14 There is some difficulty in understanding how this is effected: Playfair has suggested that the undulations of the sea propagated downwards from the surface, tend to lift up and down the pebbles at the bottom, and that such are liable, when thus quite or partially raised, to be moved onwards even by a very weak current. Should, therefore, a boulder formation be exposed during subsequent changes of level to the action of the sea, pebbles derived from it, and decreasing in size with perfect regularity according to their distance from their source, might be thus spread out. Hence I conceive that from a group of mountains, which had once existed as an island, boulders, decreasing in bulk with some degree of regularity, and beyond them pebbles degenerating with perfect regularity into sand, might be spread out, thus simulating the effects of a great debacle, which in rushing along had insensibly lost its power, and yet that *

†

Since the above was written, I have found that Mr. Trimmer, in his interesting paper on the Geology of Norfolk (Journal of the Royal Agricultural Society, vol. vii. part 2), has shown that that district subsided at least 600 feet, and was likewise upraised during the boulder or glacial period. [Trimmer 1847.] ‡ Address to the Association of American Geologists, 1844, p. 45. Journal of the Geological Society, vol. iv. p. 98.

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both boulders and pebbles had been transported by the ordinary currents of the sea; aided, in the one case, by floating coast-ice, in the other, apparently by the undulating movement of the water. The two objections, therefore, which have been here discussed, cannot, I think, any longer be considered as absolutely fatal to the theory of floating ice; and thus far the hypothesis of a debacle is no longer necessary. If the explanation here given of the transportal of boulders from a lower to a higher level be hereafter proved correct, we gain, in all cases where the horizontal distance between the boulders and the parent rock is not so great as to allow of the probability of subsequent unequal movements of elevation, a valuable measure of subsidence during a defined period. We are accustomed to precise measurements of elevation, from the ascertained heights of upraised marine remains; but it seemed quite hopeless to expect this, even in a lesser degree, with respect to subsidence,—that movement which hides under the sea the surface affected. It is marvellous that Nature should have thus marked by buoys made of stone, the former sinking of the earth’s crust, and likewise, I may add, its subsequent elevation; and that on these blocks of stone the temperature, during the long period of their transportal, may be said to be plainly engraved. Moreover, it is thus shown that the subsidence during no one entire summer was so great as to carry the coast-boulders beneath that small limit of depth at which the salt water during each ensuing winter became frozen. Note.—After this paper was read, Mr. Nicol15 objected that when the parent rock was once submerged, no further supply of boulders could be derived from it, and consequently if afterwards, each time they were afloat, only one boulder out of a hundred was dropped in water too deep for it to be refrozen in the coast-ice, after a certain time there would be none left to be carried up, during the continued subsidence, to the higher levels. This appears to me an objection of much force. I would, however, remark in the first place, that I do |323| not suppose that the boulders over the whole area of subsidence are carried far up, but only those in certain favourable situations. Secondly, several Arctic voyagers have stated that the pack-ice frequently piles up and leaves masses of boulders at a height of even 20 and 30 feet above high-water mark; now after a subsidence, the ice during the first gale would drive these boulders still higher up, and so onwards and upwards, with scarcely any tendency to carry them out to sea. In a bay open to the prevailing winds, and without any river entering it, I should imagine that the coast-ice would rarely be drifted outwards. Thirdly, I believe that any floating object thrown into the water not far from an extensive coast-line, is generally driven soon on shore: this certainly seems to be the case with the wrecks of boats; and if so, any ice-borne boulders, carried by the wind off the land, would generally be again thrown on the coast.

1

CD’s explanation for boulders found far from their native rock formations, as suggested by Lyell, was that they had been transported by floating ice. Hopkins 1848 argued that only a great rush of water and not floating ice could account for boulders found higher than their native formations. This article was CD’s response in which he proposed that boulders locked in place by coastal ice, with terrestrial subsidence, could be incrementally elevated. This theory was superseded by Agassiz’s glaciation theory.

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11 12 13 14 15

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Edward Hitchcock (1793–1864), American geologist and clergyman. Wild, upland fields. MacCulloch 1836. Joseph George Cumming (1812–68), clergyman and Vice-Principal of King William’s College on the Isle of Man. Robert Mallet (1810–81), civil engineer and seismologist. William Buckland, Dean of Westminster from 1845. Henry Thomas De la Beche (1796–1855), geologist and first director of the Geological Survey of Great Britain, 1835–55. A series of geological fault lines which run along the southern and western edges of the Yorkshire Dales. ‘Brown’ is a mistake for Augustus Frederick James Bowen (1802/04–76), who was the assistant of Bayfield (see below). They surveyed the St. Lawrence River and the coast of Labrador, 1827–40. See CCD4: 123. Henry Wolsey Bayfield (1795–1885), naval officer and geologist. A prominent 251m volcanic hill in Edinburgh. Maclaren 1839, Milne 1847. Joshua Trimmer (1795–1857), geologist, employed on the Geological Survey of England, 1846–54. South America, pp. 22 ff. James Nicol (1810–79), Scottish mineralogist and stratigrapher.

1849. Geology. By Charles Darwin, Esq., F.R.S., F.G.S. In Herschel, J. F. W. ed., A manual of scientific enquiry; prepared for the use of Her Majesty’s Navy: and adapted for travellers in general. London: John Murray, pp. 156–95. F3251 A person embarked on a naval expedition, who wishes to attend to Geology, is placed in a position in some respects highly advantageous, and in others as much to the contrary. He can hardly expect during his comparatively short visits at one place, to map out the area and sequence of widely extended formations: and the most important deductions in geology must ever depend on this having been carefully executed; he must generally confine himself to isolated sections and small areas, in which, however, there can be no doubt many interesting facts may be collected. On the other hand, he is admirably situated for studying the still active causes of those changes, which, accumulated during long-continued ages, it is the object of geology to record and explain. He is borne on the ocean, from which most sedimentary formations have been deposited. During the soundings which are so frequently carried on, he is excellently placed for studying the nature of the bottom, and the distribution of the living organisms and dead remains strewed over it. Again, on sea-shores, he can watch the breakers slowly eating into the coast-cliffs, and he can |157| examine their action under various circumstances: he here sees that going on in an infinitesimally small scale, which has planed down whole continents, levelled mountain-ranges, hollowed out great valleys, and exposed over wide areas rocks, which must have been formed or modified whilst heated under an enormous pressure. Again, as almost every active volcano is situated close to, or within a few leagues of the sea, he is admirably situated for investigating volcanic phenomena, which in their striking aspect and simplicity, are well adapted to encourage him in his studies.

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In the present state of the science, it may be doubted whether the mere collection of fragments of rock without some detailed observations on the district whence they are brought, is worthy of the time consumed and the carriage of the specimens. The simple statement that one part of a coast consists of granite, and another of sandstone or clay-slate, can hardly be considered of any service to geology; and the labour thus thrown away might have been more profitably spent, and thus saved the collector much ultimate disappointment. It is now generally recognized that both the sedimentary rocks, and those which have come from below in a softened state, are nearly the same over the whole world. A mere fragment, with no other information than the name of the place where collected, tells little more than this fact. These remarks do not at all apply to the collection of fossil remains, on which subject some remarks will presently be made; nor do they apply to an observer collecting suites of rock-specimens, with the intention of himself subsequently drawing up an account of the structure |158| and succession of the strata in the countries visited. For this end, he can hardly collect too copiously, for errors in the naming of the rocks may thus be corrected, and the careful comparison of such specimens will often reveal to him curious relations which at the time he did not suspect. In order to make observations of value, some reading and much careful thought are necessary; but perhaps no science requires so little preparatory study as geology, and none so readily yields, especially in foreign countries, new and striking points of interest. Some of the highest problems in geology wait on the observer in distant regions for explanation; such as, whether the successive formations, as judged of by the character of their fossil remains, correspond in distant parts of the world to those of Europe and North America, or whether some of them may not correspond to blank epochs of the north, when sedimentary beds either were not there accumulated, or have been subsequently destroyed. Again, whether the lowest formation everywhere is the same with that in which living beings are first present in the countries best known to geologists. These and many other such wide views in the history of the world are open to any one, who, applying thought and labour to his subject, has the good fortune to geologise in little frequented countries. A person wishing to commence geology, is often deterred by not knowing the names of the rocks; but this is a knowledge, he may rely on it, easily acquired. With half a dozen named crystalline rocks, or even by patiently familiarizing his eye (aided by a lens) to the |159| aspect of the feldspar and quartz in granite, he will know the two most essential ingredients in most igneous rocks; and in granite he will often find the glittering scales of mica replaced by a dark green mineral, less hard than the feldspar and quartz; and then he will know the third most important mineral, hornblende. The sedimentary rocks can hardly be described, except by the terms in common use: impure limestone, which cannot be readily recognized by the eye, can be distinguished by its effervescence with acids. By the repeated comparison of freshly fractured sedimentary and igneous rocks, such as sandstone and clay-slate on the one hand, and granite and lava on the other, he will learn the difference between crystalline and mechanical structure; and this is a very necessary point. Let no one be deterred from geology by the want of mineralogical knowledge; many excellent geologists have known but little; and from this reason its value has perhaps sometimes been

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underrated, for many of the obscurer points in geology, such as the nature of the metamorphic changes in rocks, and all the phenomena of metallic and other veins, almost require such knowledge. The appearances presented by the different forms of stratification (that is, the original planes of deposition) may be soon learnt in the field; though no doubt the beginner would be aided by the diagrams given in many elementary works. The two most useful works which the geologist can carry with him, are without doubt the ‘Principles’ and the ‘Elements of Geology,’ by Sir Charles Lyell. He should procure a treatise on mineralogy, for instance, ‘Phillips’s Mineralogy,’ by Allan.2 If he has the opportunity |160| to procure others, Sir H. Delabeche’s ‘Researches in Theoretical Geology’3 would be particularly desirable from discussing many of the questions which ought especially to engage the attention of a sea voyager. As he will probably visit many volcanic regions, Dr. Daubeny’s ‘Treatise on Volcanos’4 would be extremely useful; and a list is there given of special treatises on the volcanic countries likely to be visited by him. The ‘Description Physique des Isles Canaries,’ by Von Buch,5 may be cited as a model of descriptive powers. The voyager in the Temperate and Polar regions ought to have Agassiz’ work on Glaciers.6 The geologist fortunately requires but little apparatus; a heavy hammer, with its two ends wedge-formed and truncated; a light hammer for trimming specimens; some chisels and a pickaxe for fossils; a pocket-lens with three glasses (to be incessantly used); a compass and a clinometer, compose his essential tools. One of the simplest clinometers is that constructed by the Rev. Prof. Henslow: it consists of a compass and spirit-level, fitted in a small square box; in the lid there is a brass plate, graduated in a quadrant of 90 degrees, with a little plumb-line to be suspended from a milled head at the apex of the quadrant. The line of intersection of the edge of the clinometer, when held horizontally, with the plane of the stratum, gives its strike, range, or direction; and its dip or inclination, taken at right angles to the strike, can be measured by the plumb-line. In an uneven country, it is not easy without the clinometer to judge which is the line of greatest inclination of a stratum; and it is always more satisfactory to be certain of the angle than |161| to estimate it. A flat piece of rock representing the general slope can usually be found, and by placing a note-book on it, the measurement can be made very accurately. In studying the cleavage or slaty structure of rocks, accurate observations are indispensable. A mouth blow-pipe with its apparatus, and a book with instructions for its use (Phillips’s Mineralogy contains brief directions), teaches a little mineralogy in a pleasant manner. Besides the above instruments, a mountain barometer is often very necessary: a portable level would, in the case of raised sea-beaches and terraces, be useful. Messrs. Adie and Son,7 of Edinburgh, sell a hand-level, a foot in length, which is fitted with a little mirror on a hinge, so that the observer, whilst looking along the level, can see when the bubble of air is central, and thus instantly find his level in the surrounding district. This is a very valuable instrument. Mr. R. Chambers,8 moreover, and others have found, that an observer having previously ascertained the exact height of his eye when standing upright, can measure the altitude of any point with surprising accuracy; he has only to mark by the level some recognizable stone or plant, and then to walk to it, repeat the process, and keep an account how many times the levelling has been repeated in ascending to the point, the height of which he wishes to ascertain.

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A few cautions may be here inserted on the method of collecting. Every single specimen ought to be numbered with a printed number (those which can be read upside down having a stop after them) and a book kept exclusively for their entry. As the value of many specimens entirely depends on the stratum or locality whence |162| they were procured being known, it is highly necessary that every specimen should be ticketed on the same day when collected. If this be not done, in after years the collector will never feel an absolute certainty that his tickets and references are correct. It is very troublesome ticketing every separate fossil from the same stratum, yet it is particularly desirable that this should be done; for when the species are subsequently compared by naturalists, mistakes are extremely liable to occur; and it should always be borne in mind, that misplaced fossils are far worse than none at all. Pill-boxes are very useful for packing fossils. Masses of clay or any soft rock may be brought home, if small fossil shells are abundant in them. Rock-specimens should be about two or three inches square, and half an inch thick; they should be folded up in paper. To save subsequent trouble, it will be found convenient to pack up and mark outside, sets of specimens from different localities. These details may appear trifling; but few are aware of the labour of opening and arranging a large collection, and such have seldom been brought home without some errors and confusion having crept in. To a person not familiar with geological inquiry, on first landing on a new coast, probably the simplest way of setting to work, is for him to imagine a great trench cut across the country in a straight line, and that he has to describe the position (that is, the angle of the dip and direction) and nature of the different strata or masses of rock on either side. As, however, he has not this trench or section, he must observe the dip and nature of the rocks on the surface, and take advantage of every river-bank or |163| cliff where the land is broken, and of every quarry or well, always carrying the beds and masses in his mind’s eye to his imaginary section. In every case this section ought to be laid down on paper, in as nearly as possible the real proportional scale, copious notes should be made, and a large suite of specimens collected for his own future examination. The value of sections, with their horizontal and vertical scales true to nature, cannot be exaggerated, and their importance has only lately been appreciated to the full extent. The habit of making even in the rudest manner sectional diagrams is of great importance, and ought never to be omitted: it often shows the observer palpably and before it is too late (a grief to which every sea-voyager is particularly liable), where his knowledge is defective. Partly for the same reason, and partly from never knowing, when first examining a district, what points will turn out the most important, he ought to acquire the habit of writing very copious notes, not all for publication, but as a guide for himself. He ought to remember Bacon’s aphorism, that Reading maketh a full man, conference a ready man, and writing an exact man;9 and no follower of science has greater need of taking precautions to attain accuracy; for the imagination is apt to run riot when dealing with masses of vast dimensions and with time during almost infinity.10 After the observer has made a few traverses of the country and drawn his sections (and the coast-cliffs often afford him an invaluable one), he will be himself astonished how, in the most troubled country, over which the surface has been broken up and re-cemented, almost like the fragments of ice on a great river, how all the parts |164| fall into intelligible order. He

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will in his mind see the beds first horizontally stretched out one over the other in a fixed order, and he will then perceive that all the disturbance has arisen from a few nearly straight cracks, on the edges of which the beds have been upturned, and between which he will sometimes find great wedges of once heat-softened, but now crystalline rocks. He will find that large masses of strata have been removed and denuded, that is ground down into pebbles and mud, and long ago drifted away to form in some other area newer strata. He will now have a good idea of the physical structure of his district; and this much can be acquired with much greater facility than he will at first readily anticipate. In examining a district to make a section, many minor points of detail will occur for observation, which can hardly be specified; such as the nature and cause of the transitions and alterations of the different strata, the source of the sediment and pebbles, the alterations in chemical nature, either of the whole mass, or of parts, as in concretions; the presence, and grouping and state of the fossil remains; the depth and condition of the old sea-bottom, when the beds were deposited, and an infinity of similar points: Probably the best method of obtaining this power of observation, is to acquire the habit of always seeking an explanation of every geological point met with; for one mental query leads on to another, and this will at the same time give interest to his researches, and will lead him to compare what is before his eyes, with all that he has read of or seen. With his increasing knowledge he will daily find his powers of |165| observation, his very vision, become deeper and clearer. No one, however, must expect to solve the many difficulties which will be encountered, and which for a long time will remain to perplex geologists; but a ray of light will occasionally be his reward, and the reward is ample. Organic Remains.—In the sectional diagram which we have supposed to be made, the simple superposition of the beds gives their relative antiquity; but the best section which a sea-voyager can hope to make, will seldom include but a small portion of the long sequence of known geological formations. And as the voyager seldom passes over large districts, he will rarely succeed in placing in proper order, by the aid of superposition alone, the formations which he successively meets with even in the same country. Hence he must, more than any other geologist, rely on the characters of the embedded organic remains, and must sedulously collect every specimen and fragment of a specimen. By the means of fossil remains, not only will he be enabled to arrange (with the help of naturalists on his return home) the formations in the same country according to their age, but their contemporaneity with the deposits of the most distant parts of the world can thus and by no other method be ascertained; for it is now known that at each geological epoch the marine animals partook in the most distant quarters of a general similarity, even when none of the species were identically the same: thus beds have been recognized in North and South America, and in India, which must have been deposited when the chalk in Europe was accumulating beneath the sea. |166| It is highly necessary most carefully to keep the fossils found in different strata separate; it will often occur in passing upwards from one bed to another, and occasionally even without any great change in the character of the rock, that the fossils will be wholly different; and if such distinct sets of fossils are mingled together, as if found together, undoubtedly it would

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have been better for the progress of science that they had never been collected. As there is some inconvenience in keeping the fossils collected on the same day separate, this caution is the more requisite. The collector, if he be not an experienced naturalist, should be very cautious in rejecting specimens, from thinking them the same with what he has already got; for it requires years of practice to perceive at once the small, but constant, distinctions which often separate species: the same species, moreover, if collected in different localities, or in beds one placed far above the other, are generally more valuable to the geologist than new species. In formations from a few hundred to a thousand feet and upwards in thickness, the whole of which does actually belong to the same geological age, and is therefore characterized by the same fossils, most curious and important results may be sometimes deduced, if the position or relative heights at which the groups of fossils are embedded be noted; and this is a point usually neglected. For, thanks to the researches of Professor E. Forbes,11 the depth of water under which a collection of shells lived can now be approximately told; and thus the movement of the crust of the earth, whilst the strata including the shells were accumulating, can be inferred. For instance, |167| if at the bottom of a cliff, say 800 feet in height, a set of shells are buried, which must have lived under water only 50 or 100 feet in depth; it is clear that the bottom of the sea must have sunk to have allowed of the deposition of the 700 feet of superincumbent submarine strata; subsequently the whole 800 feet must have been upraised. For this same purpose, and for other ends, it is desirable that it should be noted which species are the most numerous, and whether layers are composed exclusively of single kinds. It should be also remarked, whether the more delicate bivalve shells retain their two valves united, and whether the burrowing kinds are embedded in their natural positions, as these facts show that the shells have not been drifted from afar. Where there are fossil corals, it should be observed whether the greater number of specimens are upright, in the positions in which they grew. The remark formerly made that the collection of mere fragments of rock is of little or no use to geology, is far from applicable to fossil remains. Every single fossil species, bones, shells, crustacea, corals, impressions of leaves, petrified wood, &c., should be collected, and it is scarcely possible to collect too many specimens. Even a single species without any information of any kind, if it prove a quite new form, will be valuable to the zoologist; if it prove identical with, or closely allied to a known species, it may interest the geologist. A set of fossils, however, and still more several sets, with their superposition known, cannot fail to be of the highest value; they will tell the age of the deposit, and perhaps give the key to the whole geology of the country: some of the highest problems in this |168| science wait for solution on large collections of species carefully made in distant regions. A collection of recent shells (both those living on the coast and those to be procured by the dredge off it) from the same country or island at which a collection of tertiary fossil shells is made, is generally of very great service to the palæontologist, who undertakes the description of the fossils. The collecting recent shells will, moreover, with the aid of a little study, teach the geologist some conchology, and this is an acquirement yearly becoming more necessary: the geologist should exert himself to learn some general zoology. The bones of vertebrated animals are much more rarely found than the remains of the lower marine animals, and they are almost in proportion more valuable. A person not

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acquainted with the science will hardly be able to imagine the deep interest which the discovery of a skeleton, if of higher organization than a fish, in any of the oldest formations would most justly create. The age of such a formation would have to be judged of by the co-embedded shells, and therefore, if possible, part of the slab containing the bones should include one or two shells to demonstrate their contemporaneity. Bones, however, from any formation are sure to be valuable; even a single tooth, in the hands of a Cuvier or Owen, will unfold a whole history; the heads, jaws, and articular surfaces are the most valuable; but every fragment should be brought home. Where bones are found close together, and especially if some of the parts lie in their natural positions, they should be packed |169| together. Every bone, if found even six inches beneath the black vegetable mould, should be collected; there can be no doubt that many most valuable relics have been neglected, from the supposition that they belonged to still living animals. Low cliffs of mud, gravel, and clay on the banks of streams and on sea-shores (as well as in bared reefs extending from them), are the most likely places for the discovery of the remains of quadrupeds. Gravel beds under streams of lava; fissures in volcanic rocks; peat beds, and the clay or marl underlying peat, are all favourable places. Fishes’ bones are found occasionally in all sedimentary strata, and are highly interesting. Caverns.—These most frequently occur in limestone rocks, and they have yielded a truly wonderful harvest of remains in Europe, South America, and Australia. The bones generally occur in mud, under a stalagmitic crust produced by the dripping of the lime-charged water, which requires being broken up by a pickaxe. As caverns have often been used by wild races of man as places of habitation and burial, a most careful examination should be made to detect any signs of the surface having been anciently broken up near where the bones are found. Even small islands, not now inhabited by any land quadruped, if not very distant from a continent, are almost as likely to contain osseous remains as larger tracts of land. The interest of the discovery of the remains of land quadrupeds in an oceanic island would be extreme: for instance, it has been stated that the tooth of a mastodon has been found in one of the Azores; if this were confirmed, few geologists would doubt that |170| these islands had once been united to Europe, thus enlarging wonderfully our ideas of the ancient geography of the Atlantic: so also the remains of a mastodon are said to have been brought from Timor, thus perhaps indicating the road by which this great quadruped formerly reached Australia. Fossil Footsteps.—As allied to organic remains, fossil footsteps may be here referred to. They have been observed in Europe and North America, but hitherto in no other part of the world. These curious vestiges not only proclaim the former existence of reptiles and birds at very remote periods, and in rocks often not containing a fragment of bone, but they generally prove that the level of the land subsided after the animal had left its impress on the ancient sea-beach, thus allowing thousands of feet of strata to be thrown down over them. The best place for searching for footsteps is in quarries of sandstone, in which the strata are separated by seams of shale. The best indication of their probable occurrence is the rock being rippled, that is marked with narrow little wavy ridges, such as occur on most sandy shores when the tide is down, and which indicate that the now rocky surface was once either a tidal beach or a shallow surface, over which the ancient animals walked. In the case of fossil footsteps being found, the largest slab which could possibly be removed ought to be brought away, and

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accurate drawings, or still better, casts, made of several of the footsteps. A plan from accurate measurement ought to be taken of any row of steps. The value of such fossil footsteps would be in a manifold degree increased, if the age of the deposit could be |171| determined by shells found in the same stratum, or above it. Coal Deposits.—The origin of coal presents a most curious and difficult problem in geology, and though a vast amount of information has been accumulated on the subject, yet good observations in distant countries would be of the highest value. A very brief statement of the most prominent difficulties in the theory of its origin will, perhaps, be the best guide for further inquiries. If we look first to the coal itself, the frequency with which, both in Europe and North America, upright vegetables have been found in and on the coal, and the curious relation between the presence of coal, and the nature of the clayey bed (abounding with roots) on which it rests, can leave no doubt that in these so frequent instances the vegetation, whence the coal has been derived, grew on the spot where now embedded. The regularity and wide extent of the beds of coal, and especially of certain subordinate seams in them, the stratification and fineness of the deposits alternating with the coal, and the rarity of channels (such as would have been formed by a stream or river) cutting through the associated strata, all seem pretty clearly to indicate that the coal was not formed on the surface, like a mass of peat, but under water. What, then, was the nature of those vast expanses of shallow water under which the coal was accumulated? The character of the upright fossil plants, according to our present knowledge, absolutely contradicts the idea of their having lived in the sea; yet occasionally strata, containing undoubted marine remains, are associated with the carboniferous series. |172| On the other hand, how can we believe that lakes, allowing of course their beds slowly to sink, could contain the enormous thickness, amounting in some instances to several thousand yards, of the coal-bearing strata? From these few remarks it will be seen how many points deserve careful examination in any new coal district; the chief points being, the presence of upright vegetables and trunks of trees (of the position of which careful drawings should be made), and whether furnished with roots, —the nature of the beds on which the coal rests, and generally of all the strata; the continuousness and form of the strata, and whether ripple-marked; the existence of marine animal remains, and whether such lived on the spot, or were drifted into their present positions, and many other similar points. It is superfluous to observe that all fossil plants should be collected; those found upright should be carefully distinguished from those embedded horizontally. The contents of any upright stems and of the roots should be examined; as it appears they have generally first become hollow from decay, and then been filled up with mud, which in some instances is charged with seeds and leaves. Salt Deposits.—Information is much required on this subject; and this is a case in which good suites of specimens, illustrating the nature of the rocks beneath and above the salt, would possess much interest. Do they contain any organic remains? Did such live on the spot where now buried? Do the rocks show signs of having undergone in any degree the action of heat? Are the strata regular, or are they crossed by oblique layers, showing the probable action of currents? Are there ripple-marks, |173| or beds of coarse pebbles, or other indications of the strata having been deposited in shallow water? What is the thickness,

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form, and dimensions of the beds of salt? Specimens of the salt, and of any associated saline substances, ought to be brought home in bottles for analysis. The origin of beds of salt, found in formations of very different ages in different parts of the world, is at present quite obscure; some authors attribute it to the sinking of superficial sea-water, rendered more saline by evaporation; others to the evaporation of sea-water periodically overflowing extensive low sandy tracts, like parts of the Run of Cutch;12 others suspect that its deposition is in some unknown way connected with the sea’s bottom having been heated by volcanic action. In some countries there are large lakes of brine, often covering thick beds of salt; these deserve examination: on what does such salt or brine rest, whether on the bared underlying strata, or on sand or gravel, such as cover the surrounding country? Does the salt contain the remains of animals or plants? Specimens of the salt ought to be brought home in bottles, and attention paid, whether beneath it there is any thin layer of other saline substances. Cleavage.13—The slaty structure of rocks will at first perplex the young geologist; for in proportion as it becomes well developed, the planes of stratification or of original deposition become obscure, and are often quite obliterated. As the sea-voyager, and especially the surveyor, often visits numerous points on the same line of coast, he possesses some great advantages for studying this subject, and numerous observations made with care |174| would probably give striking results. The range or strike of the cleavage is uniform over surprisingly large areas; whereas both the angle and point of dip varies much; but there is reason to believe that the planes of inclination, examined across a wide tract transversely to the range, will fall into order and show that they are the truncated edges of a few great curves or domes. The relation of the cleavage-planes to those of the stratification, or axes of elevation, should be carefully noted, and likewise to the general outline of the whole country. Long sections at right angles to the strike of the cleavage, with the dip carefully protracted on paper, would be highly interesting. When two chains of hills, each having its independent cleavage, cross each other, careful observations should be made. In all cases, any mineralogical difference, however slight, in the parallel cleavage-layers, deserves attention; but observations on this head would be hardly trustworthy, without the planes of stratification were so distinct that there could be no possibility of confounding (as has often happened) cleavage and stratification. Where a stratum of sandstone, or of any other rock without cleavage, is interstratified with a slaty rock, the surface of junction ought to be minutely examined, to see if the slate has slipped along the planes of cleavage, or whether again the mass has not been either stretched or compressed at right angles to these same planes. Fossil shells have been found by Mr. Sharpe14 in slaty rocks, which have had their shapes greatly altered, and all in the same direction; here then we have a guide to judge of the amount and direction of the mechanical |175| displacement which the surrounding slate-rocks have undergone.* Observations on cleavage, to be useful, must be numerous and very accurately made.

*

With respect to further observations on this important point, Mr. Hopkins remarks, in his paper ‘On the Internal Pressure of Rock Masses’ (Cambridge Philosoph. Transact., vol. viii.), that the observer should direct his attention especially to those cases in which the inclination of the cleavage planes to the bedding is either small, or nearly 45°. [Hopkins 1849.]

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The foliation of the metamorphic schists, that is, the origin of the layers of quartz, mica, feldspar, and other minerals, of which gneiss, micaceous, chloritic, and hornblendic schists are composed, is intimately connected with the cleavage of homogeneous slaty rocks.15 Nearly all the proposed observations on cleavage are applicable to foliation. Wherever large districts of foliated and ordinary slaty rocks unite, observations would be most desirable. These foliated rocks have all undergone metamorphic action, that is, they have been mineralogically altered and rendered crystalline by chemical attraction, aided by heat; but this is a most obscure subject, one on which it would appear that much further light will not be thrown without the aid of a profound knowledge of mineralogy or chemistry. It is now known that granitic rocks, which have been fluidified (as may be told by their sending great veins into, and including fragments of, the overlying rocks), are foliated in a more or less perfect degree: in these cases the relation of the planes of foliation with those of the adjoining rocks, which have been metamorphosed but not fluidified, would be eminently curious. Nature of the Sea-bottom.—As every sedimentary stratum has once existed as the bed of the sea or of a lake, the importance of observations on this head is obvious; |176| and no one is so favourably circumstanced for making them as a naval officer on a surveying expedition. The limits of depth under different latitudes at which the various marine animals live or are found strewed dead, is perhaps the most important point for further investigation which can be suggested in the science of geology: scarcely any observations with the dredge have been made within the tropics. Not only the shells, corals, sea-urchins, crabs, &c., brought up from different stated depths, should be preserved, but the proportionate numbers of each kind be carefully noted, as well as the nature of the sea-bottom. An observer could not labour too much in this line, and especially if he would subsequently himself undertake to tabulate and work out the results.* There is another point of view under which the bed of the sea would amply repay long-continued observations. It is well known that the nature of the bottom often changes very regularly in approaching a coast; the pebbles, for instance, increasing in size in a surprisingly steady ratio with the decreasing depth. But the means by which the pebbles are thus sorted is not known: is it by the oscillation of the waves at ordinary periods, or only during gales; or is it by the action of currents? A chart, with the nature of the bottom carefully noted on it and the currents laid down, would by itself throw some light on this question. The nature of the pebbles being observed, perhaps a point would be found whence they radiated. Excellent observations have been made by engineers on the travelling of shingle-beaches, but scarcely anything is |177| known of their movement under water. In what condition are the pebbles?—are they encrusted (as often happens) with delicate corallines—after a heavy gale are the spines of such corallines found broken? In narrow channels where there are rapid currents, and in the open sea in front of straits, where the water often suddenly deepens, what is the nature of the bottom? To what depth does the sea in a storm render the water muddy? How far from the beach, and to what depth, does the *

The best kind of dredge, and the manner of using it, are described under the Zoological Section.

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recoil of the waves, or the undertow, act, for instance, on light anchors? At what depth can the sea wear solid rock? This may sometimes be judged of by the nature of the bottom; thus, where soft mud overlies the rocky surface, we may infer that the sea can hardly now be a destroying agent, even if the inclination of the strata on the adjoining coast shows that rocky strata must once (probably, when the land stood at a different level) have extended much further. Is it at the line of high or low water, or between them, that the breakers most vigorously eat into coast-cliffs? Gigantic fragments of rock, much too large to be themselves rolled about, may be seen at the foot of almost every line of high cliffs; by what means in the course of time will these be removed, as must have happened with their innumerable predecessors? Are they slowly worn away or broken up? It may be well to recollect that in the tropics the powerful action of frost in splitting stones is entirely eliminated. Our observations, moreover, on the alluvial and sub-littoral deposits of these latitudes are not perplexed by the ancient effects of floating ice. The spray of salt-water, above the line of breakers, corrodes by |178| chemical decomposition calcareous rocks; does this play any important part on other rocks? Most bold coasts are fronted by sharp promontories and even isolated pinnacles; are these exclusively due to the greater hardness of the rocks composing them, or do not the breakers act more efficiently when eddying round any slight projection? Rocks rising steeply out of the open ocean, and exposed to the incessant wash of the heaviest surf, are often thickly coated over with various marine animals, and this would seem to indicate that pure water has not the power of gradually wearing away hard rocks, though the waves may occasionally tear off large fragments. Is the washing to and fro of pebbles, or of sand, a necessary element in the corroding power of waves on hard rocks? but how comes it that small land-locked harbours, where the waves can hardly have force to move the shingle, should ever be surrounded by cliffs, which, in most cases, clearly prove that considerable masses of rock have been worn down into mud and removed? Again, at a moderate depth, where the bottom is covered with shingle, does the rolling to and fro of the pebbles wear away solid rock? if so, the pebbles would be clean, and the submarine rocky surface probably worn into furrows or channels at right angles to the beach. Where there are violent currents and eddies, are deep round holes worn in the bottom, like those produced by eddies at the foot of cascades? This, perhaps, might be ascertained by a long pole at the turn of the tide: deep round holes have been observed on rocks formerly covered by the sea, and their origin has perplexed geologists. |179| Any person steadily attending to these subjects will occasionally be enabled to form an opinion on points at first appearing hopelessly obscure to him. The common deep-sea lead, especially if made a little bell-shaped and well armed, gives a surprisingly good picture of the bottom. There can be no doubt that whoever will for a long period collect and compare observations, made over wide areas and under different circumstances, will arrive at many curious, novel, and important results. An observer occasionally may arrive at a district where lately some great aqueous catastrophe has occurred, such as the bursting of a lake temporarily formed by a slip, or the rush of a great earthquake-wave over low land. In such cases all the effects produced, such as the thickness and nature of any deposit left—whether stratified irregularly or continuously—whether any rocky surface, over which the debacle has passed, be scored

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or smooth; all such points should be minutely described, and measurements taken of any great blocks which may have been transported: the great desideratum is accuracy and minuteness. Ice Action.—The voyager in the Polar Seas would render an excellent service to geology by observing all the effects which icebergs produce in rounding, polishing, scoring, and shattering solid rocks, and likewise in transporting gravel and boulders. Floating ice under two forms is known to transport fragments; namely, coast-ice, in which the stranded boulders are frozen, and icebergs formed by glaciers entering the sea, on the surface of which masses of rock had previously fallen from the surrounding precipices. It is obvious that in the latter case |180| the fragments would generally be quite angular, and they could not be landed in water shallower than the thickness of the submerged ice, requisite to float the berg. On the other hand, the boulders frozen in coast-ice would generally be previously water-worn, and they could be landed on an ordinary beach, and might be driven by the force of the pack high and dry, and perhaps left piled in strange positions. All facts illustrating the difference in the results produced by coast-ice and true icebergs would be very valuable. Do the boulders fixed on coast-ice, when driven over rocky shoals, become themselves scored? Wherever there was reason to believe that a surface had been scored by recent ice-action, a minute description and drawings ought to be made of the depth, length, width, and direction of the grooves; and even large slabs brought home. On true icebergs are the fragments of rock generally fixed or loose; when icebergs turn over, are fragments frequently seen embedded in that part which was under water; and how were they fixed there? The nature, number, size, form, and frequency of occurrence of all fragments of rock seen on floating ice ought to be recorded, and the distance from their probable source. A polar shore, known from upraised organic remains to have been lately elevated, would be eminently instructive. Do great icebergs force up the mud and gravel at the bottom of the sea in ridges like the moraines of glaciers? Can shells, or other marine animals, live in a shallow sea, often ploughed up and rendered turbid by the stranding of icebergs? The dredge alone could answer this. The means to distinguish the effects of ancient floating ice |181| from those produced by ancient glaciers is, at present, a great desideratum in geology. M. Agassiz’ work on Glaciers,16 with its admirable plates, ought to be procured by any one going to the colder regions of the north or south. Erratic boulders occur in Europe, N. America, and in the southern parts of S. America, which, it is believed by most geologists, were transported by ice; those near mountains, by ancient glaciers; and those on the lowlands, by floating ice. Erratic boulders, when not of gigantic size, may be confounded with rounded stones, transported by occasional great floods or by the coast-action of the surf during slow changes of level of the land. Masses of granite, from often disintegrating into large, apparently water-worn boulders, and then rolling downwards, have several times been erroneously described as belonging to the erratic class. Where the nature of all the rocks in the vicinity is not perfectly known, great size and the angularity of the fragments (though by no means a constant concomitant) are the most obvious distinctive characters; but even when the surrounding country is not at all

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known, the composition of a single isolated hill or small island may easily be ascertained, and if large fragments of foreign rock lie strewed on its surface, these may be assumed almost certainly to be erratic boulders. Here, however, a caution has been found necessary; for in the case of fragments of sedimentary rocks, they may be the last remnant of a denuded overlying formation. Wherever erratic boulders are found, their composition, form—especially attending to whether they are angular, water-worn, or scored, and |182| their size, from actual, though rude measurements, should be given. Both in the north and south a peculiar formation called till has been found connected with erratic boulders; it consists generally of mud, containing angular and rounded stones of all sizes up to the largest boulders, mingled in utter confusion, and generally without any stratification. Such deposits should be examined. Sometimes when they are stratified, the upper beds have been found violently contorted, whilst the lower ones are undisturbed, showing that the violence has not proceeded from below, as in ordinary geological cases. Sir C. Lyell has suggested that this effect has been produced by the stranding of great icebergs. As far as our present knowledge goes, the above enumerated phenomena—such as scored, mamillated, and polished rocks, moraines, erratic boulders, and beds of till, though occurring in latitudes where glaciers do not now occur, where the sea is never frozen, and where icebergs are never drifted, yet have not been observed in either hemisphere higher than about latitude 40°. Hence, on whatever coast ancient ice-action might be discovered, the limit of latitude towards the tropics at which it ceases ought to be carefully investigated. Observations are much wanted on the west coast of N. America and the east coast of Asia; and again in New Zealand and other islands of the Southern Ocean. The period of the ice-action is pretty well ascertained in Europe and North America, and a very great service would be rendered to geology if the same point could be clearly made out in the southern hemisphere; for it might greatly influence our |183| ideas on the climate of the world during the late tertiary periods. Any shells embedded in till (though, unfortunately, of very rare occurrence) would decide this point, and it might probably be closely judged of, if till or boulders were found resting on, or covered by, shell deposits. Distribution of Organic Beings.—As geology includes the history of the organic inhabitants, as well as of the inorganic materials, of the world, facts on distribution come under its scope. Earth has been observed on icebergs in the open ocean; portions of such earth ought to be collected, washed with fresh-water, filtered, gently dried, wrapped up in brown paper, and sent home by the first opportunity to be tried, with due precautions, whether any seeds still alive are included in it. Again, the roots of any tree cast up on an island in the open ocean should be split open, to see if any earth or stones are included (as often happens), and this earth ought to be treated like that from icebergs: it is truly surprising how many seeds are often contained in extremely small portions of earth. Any graminivorous bird, caught far out at sea, ought to have the contents of its intestines dried for the same object. The zoologist who, with a towing-net, fishes for floating minute animals, ought to observe whether seeds are thus taken. These experiments, though troublesome, undoubtedly, would be well worth trying. All facts or traditional statements by the inhabitants of any island or coral-reef, on the first arrival of any bird, reptile, insect, or remarkable plant, ought to be collected. In those

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rare cases in which showers of fish, reptiles, shells, earth, seeds, confervæ,17 &c., have fallen from the sky, every fact should be recorded, and specimens collected. Volcanic Phenomena.—The voyager will probably have |184| ample opportunities of examining volcanic islands, and perhaps volcanoes in eruption. With respect to the latter, he ought to record all that he sees: should the exact position of the orifice be known, he might, perhaps, by observing some point in a cloud, measure with a sextant to what height the fragments were shot forth, and the height of the often flat-topped column of ashes. Having surveying instruments, he ought to map, as carefully as time will permit, any crater remarkable for its size, depth, or peculiar form. M. Élie de Beaumont has found that, owing to the fluidity of lava, streams never consolidate into a thick, moderately-compact mass, except on a surprisingly gentle inclination. On a slope of above 2 or 3°, the stream consists of extremely irregular masses, often forming a hollow vault within. Fresh observations on this point are much wanted in regard to lavas of different composition. The measurements can easily be made by a sextant and artificial horizon.* In |185| making such observations, comparatively recent streams must be chosen, so that there can be no doubt that the whole consists of a single stream: this cannot be judged of without examining the whole line between the two points of measurement, for some liquid lavas thin out to a very fine edge; and two streams, one over the other, may be thus very easily mistaken for a single one. The composition, thickness, and degree of cellularity of any lava-stream, of which the slope is measured, ought to be described as seen on the sides of fissures, and wherever its internal structure can be made out. Round many active and extinct volcanoes, both on continents and on islands, there is a circle of mountains, steep on their inner, and gently inclined on their outer flanks. The volcanic strata, of which they are composed, everywhere dip away from the central space, but at a considerably higher angle than it is believed lava can consolidate into such thick and compact masses. These mountains form the so-called craters of elevation, the origin of which has excited much controversy, and which demand further examination. There is a grand range of mountains of this class at the Mauritius and at St. Jago in the Cape de Verdes, parts only of which have been described. The chief points to attend to are, the inclination of the streams by actual measurement, their thickness, compactness, and composition; the form and height of the mountains, whether traversed by very many dikes, |186| of which the common direction ought to be recorded; how far the mountains stand apart, and the diameter and outline of the rude circle which they together form. In fact, a most useful

*

M. Élie de Beaumont gives the following directions (Mémoires pour servir, &c., tom. iv. p. 173):—[de Beaumont 1838.] The method I am in the habit of employing for these kinds of measurements is simple and easy, and a description of it may save useless trouble to others. I place on the edge of the sextant, and behind the fixed mirror, a small piece of white paper, in which there is a narrow opening (ouverture étroite) corresponding to the axis of the telescope. On the exterior surface of the paper a black line is drawn, perpendicular to the plan of the graduated circle, and passing through the centre of the opening above mentioned. A quantity of mercury is poured into a vessel sufficient to form a plane horizontal surface of a certain extent. The telescope of the sextant is then directed vertically over the mercury, and the image of the black line sought for. When this is found, I am certain that the visual ray from the image in the mercury can only deviate from the perpendicular, in so far as the line is not without breadth, and the opening has a sensible size. These two sources of error can be diminished so that the maximum of error shall not exceed a minute. Being once certain of the verticality of the visual ray from the image of the black line, I have only to make the image of any object reflected from the moveable mirror coincide with that of the black line, to have the angle between the vertical, and the line drawn from the centre of the instrument to the object in question, which may be any distant point on the surface of a bed of lava, a glacier, a road, a river, &c.

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service would be rendered by mapping any of these craters of elevation, or, what would be more feasible, drawing from actual measurements two sections at right angles to each other, across the circle. Some streams of lava, especially those belonging to the trachytic series (harsh, generally rather pale-coloured lavas, with crystals of glassy feldspar), are laminated. The course of the layers with respect to the course of the stream ought to be minutely studied, both on the surface, at the termination, and flanks of the stream; and, if by a most fortunate chance there should have been formed a transverse section, throughout its entire thickness: this would be a very interesting subject for investigation. A series of specimens ought to be brought away to illustrate the nature of the lamination. Aerial Dust.—Fine brown-coloured dust has often fallen on vessels far out at sea, more especially in the middle of the Atlantic. This should be collected; the direction and force of the wind (and the course of any upper current, as shown by the movement of the clouds) on the same day, and for some previous days, ought to be recorded, as well as the date, and the position of the ship. Such dust has been shown by Ehrenberg18 to consist, in many cases, almost entirely of the siliceous envelopes of infusoria. The distance to which real volcanic dust is blown is, likewise, in some respects well worth determining. Elevation of the Land.—The changes of level, often |187| accompanying earthquakes, will be treated of by Mr. Mallet,19 but a few remarks on the nature of the evidence to be sought, on changes of level not actually witnessed by man, may be here inserted. Many appearances, such as lines of inland cliffs, of sand-hillocks, eroded rocks, and banks of shingle, often indicate the former effects of the sea on the land when the latter stood at a lower level. But the best evidence, and the only kind by which the period can be ascertained (for the appearances above enumerated, though well preserved, may sometimes be of considerable antiquity), is the presence of upraised recent marine remains. On land which has been elevated within a geologically recent time, sea shells are often found, either embedded in thin layers of sand and mould, or scattered on the bare surface. In these cases, and especially in the latter case, great caution is requisite in testing the evidence; for man, birds, and hermit-crabs often transport, in the course of ages, an extraordinary number of shells. In the case of man, the shells generally occur in heaps, and there is reason to believe that this character is long preserved. To distinguish the shells transported by animals from those uplifted by the movement of the earth, the following characters may be used:—Whether the shells had long lain dead under water, as indicated by barnacles, serpulæ, corallines adhering to their insides; whether the shells, either from not being full grown or from their kind, are too small for food; remembering that certain shells, as mussels, may be unintentionally transported by man or other animals in their young state adhering to larger shells; and lastly, whether all the specimens have the same appearance of antiquity. Some |188| shells, which have been exposed for many ages, yet retain their colours in a surprising manner. The very best evidence is afforded by barnacles and boring shells being found attached to or buried in the rock, in the same positions in which they had lived; these may be sometimes found by removing the earth or birds’ dung covering points of rock. Where shells are embedded in a superficial layer of soil, though it may appear exactly like vegetable mould, specimens of it

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should be preserved, for the microscope will sometimes reveal minute fragments of marine animals. In all these cases, specimens of the shells, though broken and weathered, and having a wretched appearance, must carefully be preserved; for a mere statement that such upraised shells resembled those still living on the beach is absolutely of no value. It should be noticed whether the proportional numbers between the different kinds appear to be nearly the same in the upraised shells and in those now cast on the beach. The height at which the marine remains occur above the level of the sea should be measured. In confined situations where the change of level appears to have been small, much caution must be exercised in receiving any evidence; as a change in the direction of the currents (resulting from alterations in neighbouring submarine banks) may cause the tide to flow to a somewhat less height, and thus give the appearance of the land having been upraised. Wherever a tract of country can be proved to have been recently elevated, its surface, as exhibiting the late action of the sea, is a fertile field for observation. On such coasts, terraces rising like steps, one above another, often occur. Their outline and composition should be |189| studied, diagrams made of them, and their height measured at many and distant parts of the coast. There is reason to believe that in some instances such terraces range for surprisingly long distances at the same height. Where several occur on opposite sides of a valley a spirit level is almost indispensable, in order to recognize the corresponding stages. Where ranges of cliffs exist, the marks of the erosion of the waves may sometimes be expected to occur, and as these generally present a defined line, it is particularly desirable that their horizontality should be ascertained by good levelling instruments, and if not horizontal, that their inclination should be measured. Where more than one zone of erosion can be detected all should be levelled, for it does not necessarily follow that the several lines are parallel. Along extensive coasts, and round islands which have been uplifted to a considerable height, and where we now walk over what was, within a late geological period, the bed of the sea, it would be well to observe whether extensive sedimentary deposits have been upraised; for it has often been tacitly assumed that sedimentary deposits are in process of formation on all coasts. Subsidence of the Land.—This movement is more difficult to detect than elevation, for it tends to hide under water the surface thus affected. Evidence, therefore, of subsidence is very valuable; and this movement, moreover, has probably played a more important part in the history of the world than elevation, for there is reason to believe that most great formations have been accumulated whilst the bed of the sea was sinking. Subsidence may sometimes be inferred from the form of the coast-land; |190| for instance, where a line of cliffs, too irregular to have been formed by elevation alone, plunges precipitously into a sea so profoundly deep that it cannot be supposed that the now deeply submerged portions of the cliff have been simply worn away by the currents. The direct evidence of subsidence, if not witnessed by man, is almost confined to the presence of stumps of trees, peat-beds, and ruins of ancient buildings, partly submerged on tidal beaches. Ancient buildings may sometimes afford such evidence in unlikely situations: it has been asserted, that in one of the volcanic islands in the Caroline archipelago there are ruins with the steps covered by the sea. Again, at Terceira, at the Azores, there is an old church or monastery said to be similarly circumstanced.

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Coral Reefs.*—The most important point with respect to coral reefs, which can be investigated, is, the depth at which the bottom of the sea, outside the reef, ceases to be covered with a continuous bed of living corals. This can be ascertained by repeated soundings with a heavy and very broad bell-shaped lead, armed with tallow, which will break off minute portions of the corals or take an exact impression of them: it can thus also instantly be seen how soon the bottom becomes covered with sand. This limit of depth ought to be ascertained in different seas, under different latitudes, and under different exposures. For collecting specimens of the corals, it is to be feared that the dredge would become entangled, but chains and hooks may be lowered for this purpose. There is reason to suspect that different species of corals |191| grow in different zones of depth; so that in collecting specimens, the depth at which each kind is found, and at which it is most abundant, should be carefully noted. It ought always to be recorded whether the specimen came from the tranquil waters of a lagoon or protected channel, or from the exposed outside of the reef. The small reefs within the lagoons of certain atolls (or lagoon-islands) in the Indian Ocean all rise to the surface; whereas in other atolls not a single reef rises within several fathoms of the same level. It would be a curious point to ascertain whether the corals in these cases consisted of the same species; and if so, on what possible circumstance this singular difference in the amount of their upward growth has depended. Any facts which can elucidate the rate at which corals can grow under favourable circumstances, will ever be interesting: nor should negative facts, showing that within a given period reefs have not increased either laterally or vertically upwards, be neglected. In a full-grown forest, to judge of its rate of growth, a part must be first cut down; so is it probably with reefs of corals. The aborigines of some of the many coral islands in the great oceans might perhaps adduce positive facts on this head; for instance, the date might be known when a channel had been cut to float out a large canoe, and which had since grown up. For the classification of coral reefs, the most important point to be attended to, is the inclination of the bed of the adjoining sea; and, secondly, the depth of the interior lagoon in the case of atolls, and of the channel between the land and the reef, in Encircling or Barrier, and in |192| Fringing reefs. Whenever it is practicable, soundings ought to be taken at short ascertained distances, from close to the breakers in a straight line out to sea, so that a sectional outline might be protracted on paper. In those cases in which the bottom descends by a set of ledges or steps, their form ought to be particularly attended to; and whether they are covered with sand or by dead or living coral; and whether the corals differ on the different ledges: the same points should be attended to within the lagoon, wherever its bed or shore is step-formed: the origin of these steps or ledges is at present obscure. In the Indian and Pacific Oceans there are entire reefs, having the outline of atolls or lagoon-islands lying several fathoms submerged; there are likewise defined portions of reefs both in atolls and in encircling reefs similarly submerged. It would be particularly desirable to ascertain what is the nature of these submerged surfaces, whether formed of sand or rock or living or dead corals. In some cases two or more atolls are united by a linear reef; the form of the bottom on *

The only work specially written on this subject is ‘The Structure and Distribution of Coral Reefs,’ by Mr. Darwin.

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each side of this connecting line ought to be examined. Where two atolls or reef-encircled islands stand very near each other, the depth between them might be attempted by deep soundings: the bottom has been struck between some of the Maldiva atolls. Generally the form and nature of the reefs encircling islands ought to be compared in every respect with the annular reefs forming atolls. On the shores of every kind of reef, especially of atolls and of land encircled by barrier reefs, evidence of the slow sinking of the land should be particularly sought for; |193| for instance, by stumps of trees, the foundation-posts of sheds, by wells or graves or other works of art, now standing beneath the level of high-water mark, and which there was good reason to believe must have once stood above its level. The observer must bear in mind that cocoa-nut trees and mangroves will grow in salt-water. If such evidence be found, inquiry ought to be made whether earthquakes have been felt. On the other hand, all masses of coral standing so much above the level of the sea that they could not have been thrown up by the breakers during gales of wind, at a period when the reef had not grown so far out seaward, should be investigated and their height measured. There is reason to believe that some coral-reefs have been thought to have been upraised, owing to the effect of the lateral or horizontal extension of the reefs having been overlooked; for the necessary result of this outward growth is gradually to break the force of the waves, so that the rocks, now further removed from the outer breakers, become worn to a less height than formerly, and the more inland corals not being any longer constantly washed by the surf, cease to live at a level at which they once flourished. It is indispensable that specimens of all upraised corals, and especially of the shells generally associated with them, should be collected; for there can be no doubt that ancient strata containing corals, have in some instances been confounded with recent coral-rock. The importance of ascertaining whether coral-reefs have undergone, or are undergoing, any change of level, depends on the belief that all the characteristic differences between Atolls and Encircling reefs on the one hand, and |194| Fringing reefs on the other, depend on the effect produced on the upwardly-growing corals by the slow sinking or rising of their foundations. A thick and widely-extended mass of upraised recent coral-rock has never yet been accurately examined, and a careful description of such a mass—especially if the area included a central depression, showing that it originally existed as an atoll—is a great desideratum. Of what nature is the coral-rock; is it regularly stratified or crossed by oblique layers; does it consist of consolidated fine detritus or of coarse fragments, or is it formed of upright corals embedded as they grew? Are many shells or the bones of fish and turtle included in the mass, and are the boring kinds still in their proper positions? The thickness of the entire mass and of the principal strata should be measured, and a large suite of specimens collected. In conclusion, it may be re-urged that the young geologist must bear in mind, that to collect specimens is the least part of his labour. If he collect fossils, he cannot go wrong; if he be so fortunate as to find the bones of any of the higher animals, he will, in all probability, make an important discovery. Let him, however, remember that he will add greatly to the value of his fossils by labelling every single specimen, by never mingling those from two

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formations, and by describing the succession of the strata whence they are disinterred. But let his aim be higher: by making sectional diagrams as accurately as possible of every district which he visits (nor let him suppose that accuracy is a quality to be acquired at will), by |195| collecting for his own use, and carefully examining numerous rock-specimens, and by acquiring the habit of patiently seeking the cause of everything which meets his eye, and by comparing it with all that he has himself seen or read of, he will, even if without any previous knowledge, in a short time infallibly become a good geologist, and as certainly will he enjoy the high satisfaction of contributing to the perfection of the history of this wonderful world.

1

2 3 4 5 6 7 8 9 10 11 12 13 14 15

16 17 18 19

CD was invited by J. F. W. Herschel to contribute a chapter on geology to an Admiralty guide for scientific travellers. The chapter is clearly based on CD’s experiences on the Beagle voyage and reveals much about his practical day-to-day work in the field and on board ship. See J. Geikie’s assessment of the chapter in LL1: 328–9. (DO) W. Phillips 1837. De la Beche 1834. Charles Giles Bridle Daubeny (1795–1867), chemist and botanist, professor of chemistry, Oxford University, 1822–55. Daubeny 1826. Christian Leopold Buch (1774–1853), German geologist and geographer. Buch 1836. Agassiz 1840. Alexander James Adie (1775–1858), optician and instrument maker. Robert Chambers (1802–71), Edinburgh publisher, writer, geologist and anonymous author of Vestiges of the natural history of creation (1844). Francis Bacon (1561–1626), lawyer, statesman and philosopher who was considered a founder of modern science in CD’s day. Bacon 1625. These remarks are well-attested in CD’s pocket field notebooks from the Beagle voyage. See Chancellor and van Wyhe eds. Beagle notebooks. Forbes 1843. Rann of Kachchh (or Kutch), a vast shallow wet-land in Gujarat, India. A term used to denote the regular fissures of slaty rocks. Sharpe 1847. Foliation was a term used to describe the fissures of metamorphic schists. CD differed from most geologists of his day in maintaining that the fissures were not ‘the constituent parts of each layer… separately deposited as sediment, and then metamorphosed.’ (South America, p. 165) Instead CD maintained that ‘in most cases foliation and cleavage are parts of the same process: in cleavage there being only an incipient separation of the constituent minerals; in foliation a much more complete separation and crystallization’ (South America, p. 166. See ibid. pp. 167–8.) Agassiz 1840. Algae with branching filaments that form scum in still or stagnant fresh water. Ehrenberg 1844. Mallet’s chapter was entitled ‘Earthquake phenomena’.

1849. On the use of the microscope on board ship. In Owen, R., Zoology. In Herschel, J. F. W. ed., A manual of scientific enquiry; prepared for the use of Her Majesty’s Navy: and adapted for travellers in general. London: John Murray, pp. 389–95. F1822 The following remarks embody the experience of Mr. Charles Darwin, F.R.S., on this subject, the importance of which increases as the science of zoology advances.1

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The facility in examining the smaller invertebrate animals, either alive or dead, depends much more on the form of the microscope used than would be at first expected. The chief requisite of a simple microscope for this purpose is strength, firmness, and especially a large stage; the instruments generally sold in this country are much too small and weak. The stage ought to be firmly soldered to the upright column and have no movement; besides the strength thus gained, the stage is always at exactly the same height, which aids practice in the delicate movements of the hand. The stage should be able to receive saucers, three inches in internal diameter. A disc of blackened wood, with a piece of cork inlaid in the centre, made to drop into the same rim which receives the saucers, is useful for opaque and dry objects: there should also be a disc of metal of the same size, with a hole and rim in the centre to receive plates of glass, both flat and concave, in diameter one inch and a half, for dissecting minute objects; a plate of glass of three inches diameter lets in too much light and is otherwise inconvenient. Close under the stage there should be a blackened diaphragm, to slip easily in and out, in order to shut off the light |390| completely; in this diaphragm there may be a small orifice with a slide, to let in a pencil of light for small objects. The whole microscope should be screwed into a solid block of oak, and not into the lid of the box as is usual. The mirror should be capable of movement in every direction, and of sliding up and down the column; on one side there must be a large concave mirror, and on the other a small flat one; these mirrors ought to be fitted water tight in caps, made to screw off and on; and two or three spare mirrors ought undoubtedly to be taken on a long voyage, as salt water spilt on the mirror easily deadens the quicksilver. A small cap is very convenient to cover the mirror when not in use, and often saves it from being wet. The vertical shaft by which the lenses are moved up and down should be triangular (as these work much better than those of a cylindrical form), and there should be on both sides large milled heads; with such, there is no occasion for fine movements of adjustment, which always tend to weaken the instrument. The horizontal shaft should be capable of revolving, and should be moved to and fro by two milled heads (for the right and left hands), but the left milled head must be quite small, to allow of the cheek and eye approaching close to the lenses of high power. The horizontal shaft must come down to the stage. The most useful lenses are doublets of 1 inch and 6–10ths of an inch (measured from the lower glass of the doublet) in focal distance; a simple lens of 4 or 5–10ths of an inch is a very valuable power; and, lastly, Codrington lenses2 (of the kind sold by Adie of Edinburgh),3 |391| of 1–10th, 1–15th, and 1–20th focal distances, have been found most useful by two of the most eminent naturalists in England. With a little practice it is not difficult to dissect under the 1–10th lens, and some succeed under the 1–20th. A person not having a compound microscope might procure a 1–30th of an inch Codrington lens. All the lenses (except the largest doublet) should be made to drop, not screw, into the same ring; the large doublet may slip off and on the opposite end of the horizontal shaft. The best saucers have a flat glass bottom, with thin upright metal sides (silvered within); there should be at least four of them, being in depth (inside measure) 3–10ths, 5–10ths, 7–10ths, and a whole inch. Circular discs of fine-textured cork, of the size of the saucers (with one or two circular springs of steel-wire to keep the cork at the bottom of the water), serve for fixing objects to be dissected by direct

1849. On the use of the microscope on board ship

237

instead of transmitted light. For this end short fine pins and lace-needles should be procured; wherever it is possible, the animal ought to be fixed to the cork under water. Of the smaller plates of glass of an inch and a half in diameter, some should be flat and some slightly concave; the latter are very useful—saucers of this small diameter are inconvenient. The simplest and most useful instruments for minute dissection are the triangular glove-needles, which with a little cotton-wool and sealing-wax can be easily fixed into pieces of large-bored thermometer tubes; a stock of tubes and needles should be taken on a voyage. With these needles (by keeping the object only just immersed in a drop of water, which can be regulated by the suction |392| of blotting-paper), wonderfully minute objects can be dissected; needles bent at their tips are convenient for some purposes. Arm supports are useful in minute dissections; two blocks of wood with inclined surfaces, coming up a little below the level of the stage, and resting partly on the stand of the microscope, can be made by a common carpenter. As it is often rather dark in the cabins of ships, a large bull’seye glass on a stand (such as are sold with most compound microscopes) would be most useful to condense the light from a lamp on an opaque object, or to increase it when transmitted. Besides the needles, fine pointed forceps, pointed scissors, and eye scalpels are requisite. The French use an instrument called a microtome, and consider it most useful; others prefer finely pointed scissors, with one leg long and thick, to be held like a pen, and the other quite short, to be pressed by the fore finger, and kept open by a spring. A live-box to act as a compressor, or still better a proper compressor closed by a screw, and both made to drop into the rim of the stage, are valuable aids for making out the structure of transparent animals or organs. The observer should be provided with three slips of glass, or still better with three circular plates, made to drop into the stage of his microscope, and graduated into tenths, hundredths, and thousandths of an inch, to serve as micrometers, on which to place and measure any object he is examining. Some watch-glasses are very useful as temporary receptacles for small sea-animals. Minute parts after dissection can be preserved for years in very weak spirits of wine, by covering them, when placed on slips of glass, by small portions of very thin |393| glass (both sold for this purpose), and cementing the edges with gold-size.* When time and opportunity concur for the anatomical examination of an animal, the following notes or heads of observation will guide the dissector to the facts which it is most desirable to determine and note down.

1 2

3

*

See CD to Owen 26 March 1848 in CCD4 and ML1: 59–60. Mistake or misprint for ‘Coddington lenses’ which are made of a single lens with a grooved diaphragm around the circumference which allows for sharp images at higher magnification. Named after Henry Coddington (1798/9–1845), mathematician and clergyman, Tutor at Trinity College, Cambridge, 1822–33. Alexander James Adie (1775–1858), optician and instrument maker.

A microscope such as here described, and most of the apparatus, can be seen at Messrs. Smith and Beck’s, opticians, of Colman Street, London.

238 No.

1849. On the use of the microscope on board ship Date

18

Notes of Dissections performed at Animal’s Name Sex Age Weight Length of body, from extremity of jaws to root of tail –– of head of tail Situation of testes –––– of preputial orifice –––– of vaginal orifice –––– of anus –––– and number of mammæ Abdominal muscles –––– ring Stomach simple length greatest circumference Observations. complex number of sacs relative size Obs. Omentum Mesentery Intestines length greatest circumference –– of small –– of small –– of cæcum –– of cæcum –– of large –– of large Observations Anus glands |394| Cloaca Liver situation number of lobes weight Observations Gall-bladder, size situation –––––––– structure Bile, enters intestine Pancreas form situation its secretion, enters intestine

1849. On the use of the microscope on board ship

No. Spleen

Lungs

Branchiæ Heart

situation form weight situation length weight number of lobes, right structure, air cells, &c. situation weight length shape and structure

Venæ cavæ Aorta, primary branches Trachea, number of rings Larynx of tail Pharynx Epiglottis Thyroid Glands Salivary glands Tongue, length Nostrils Eye-lids Eye Pupil, form Lachrymal gland Ear Brain, weight Spinal cord, length Supra-renal glands |395| Kidneys situations form weight of both papillæ, number of form Ureters terminate

239

Date

18

breadth, right

left left

breadth

structure

papillæ

form, &c.

length

breadth

240

1849. On the use of the microscope on board ship

No.

Date

Urinary bladder

situation size shape Testes size structure Vasa deferentia terminate Vesiculae seminales

Prostate

Cowper’s glands

Penis Urethra Ovaries

Uterus

Vagina Oviduct

size structure terminate

size structure terminate size structure terminate length situation size shape Observations length of cornua –– of Fallopian tubes –– of body position

length form termination Peculiarities of muscles –––– air-sacs –––– glandular organs Morbid appearances Calculi Entozoa Epizoa

muscle

18

1850. On British fossil Lepadidæ

241

1849. [Letter on floating ice]. In Murchison, R. I., On the distribution of the superficial detritus of the Alps, as compared with that of Northern Europe. [Read 30 May] Proceedings of the Geological Society of London 4 (1): 65–9, p. 67. F1816 I feel most entirely convinced that floating ice and glaciers produce effects so similar, that at present there is, in many cases, no means of distinguishing which formerly was the agent in scoring and polishing rocks. This difficulty of distinguishing the two actions struck me much in the lower parts of the Welsh valleys.1

1

See CCD4: 236–7.

1850. On British fossil Lepadidæ. By C. Darwin, Esq., F.R.S. G.S. &c. [Read 5 June] Quarterly Journal of the Geological Society of London 6: 439–40. F16791 [This paper was withdrawn by the author with the permission of the Council.] [Abstract.] Mr. Darwin noticed that great confusion exists in the nomenclature of the comparatively few species of Cirrhipeds, hitherto found in a fossil state; arising both from the easy separation of the several dissimilar valves soon after the death of the animal, and from the imperfect characters afforded by the valves themselves, which are, as it were, but parts of the crustacean carapace, neither accompanied with, nor distinctly impressed by, any of the soft parts of the animal. He then pointed out such particular valves as were sufficiently distinct, and had sufficiently constant characters to be considered as characteristic |400| of genera,—as, for instance, the keel, or dorsal, valve in Scalpellum, and the scutal, or inferior lateral, valve in Pollicipes. The pedunculated cirrhipeds (Lepadidæ) were stated to have made their first appearance in the lower oolite, and to have reached their culminant point in the cretaceous epoch. The absence of sessile cirrhipeds in the earlier and secondary formations, and their occurrence for the first time in the eocene deposits, were then noticed, the author dwelling on the characters of the genus Verruca, and pointing out that, as a type of a group intermediate between, and of equal value with, the sessile and the pedunculate cirrhipeds, it offered no real exception to the rule that sessile cirrhipeds do not occur in the secondary formations; but that, on the contrary, it harmonizes with the law of relation between serial affinities of animals and their first appearance on this earth. Mr. Darwin concluded with a few observations on the comparative ranges of recent and fossil cirrhipeds, and on the close affinities between the extinct and the living forms.

1

CD later published his conclusions in Fossil Cirripedia (1851). See CCD4. Some of the remarks in this paper were tantamount to a declaration of evolution.

1852. Bucket ropes for wells

242

1851. [Note on a Galapagos lichen]. In Hooker, J. D., An enumeration of the plants of the Galapagos Archipelago; with descriptions of those which are new. [Read 4 March, 6 May, and 16 December 1845.] Transactions of the Linnean Society of London 20: 164. F2017 [Usnea plicata] Hab. James Island, “hanging from the boughs of the trees in the upper damp region, where it forms a considerable proportion of the food of the large tortoise.” (Charles Darwin, Esq.)

1851. Testimonials for Thomas H. Huxley, F. R. S., candidate for the Chair of Natural History at the University of Toronto. London: Richard Taylor printed, p. 4. F3441 Down Farnborough Kent Oct. 9. 1851 Dear Sir I have much pleasure in expressing my opinion, from the high character of your published contributions to Science, and from the course of your studies during your long Voyage, that you are excellently qualified for a Professorship in Natural History.— You have my best wishes for success in your present application, & I beg to remain Dear Sir Your’s faithfully Charles Darwin

1

This letter was written in support of the unsuccessful application for the Chair of Natural History at the University of Toronto by naturalist Thomas Henry Huxley (1825–95). See CCD5: 65. Huxley later became one of the most outspoken supporters for CD’s theory of common descent or evolution, though not of natural selection.

1852. Bucket ropes for wells. Gardeners’ Chronicle and Agricultural Gazette no. 2 (10 January): 22. F1680 I suffer from the serious misfortune of a well 325 feet deep. It is worked by two buckets, and a chain, which, from its great length, is necessarily very heavy. Would a wire rope (galvinised) answer? This, I presume, might be tight and thin; it would have to carry, at each end, a strong and heavy bucket, holding 12 gallons. The rope would have to work over, and, I presume, once quite round, a wheel only 14 inches in diameter. Would any of your correspondents have the charity to give the result of any actual experience of light wire rope; such would be of value, probably to others, as well as to myself. C.R.D.1

1

A reply appeared in the next issue of Gardeners’ Chronicle (no. 3, 17 January 1852, p. 38): ‘Wire Rope (see p. 22).— I certainly cannot recommend wire rope when it is required to work round a

1853. Tanks and hose

243

sheave, unless the diameter of the sheave or drum is at least 3 feet. One broke with me in a very few weeks, though only 10 feet long, and the weight at the end only 70 lbs., being worn and broken where it worked over the sheave. C.L.C’. See CCD5.

1852. [Letter on the bookselling question]. In Parker, J., The opinions of certain authors on the bookselling question. London, p. 27. F1912 Down, Farnborough, Kent, May 5th, 1852. Sir,1 As an author of some scientific works, I beg to express strongly my opinion, that, both for the advantage of authors and the public, booksellers, like other dealers, ought to settle, each for himself, the retail price. I am, your obedient servant, Charles Darwin.

1

John William Parker (1792–1870), bookseller and publisher at 445 West Strand, London. See CCD5.

1853. [Description of Patagonian fossil beds]. In Owen, R., Description of some species of the extinct genus Nesodon, with remarks on the Primary Group (Toxodontia) of hoofed quadrupeds, to which that genus is referable. [Read 25 November 1852 and 13 January 1853] Philosophical Transactions of the Royal Society 143: 309. F1820 The fossils above described were discovered on the coast of Patagonia to the south of Port St. Julian, and my friend Mr. Charles Darwin, F. R. S., has kindly communicated to me the following opinion as to the formation in which they were imbedded:—“These beds resemble mineralogically the upper ancient tertiary formation of Patagonia, but Ehrenberg found the included microscopical organisms wholly different from those of the ancient tertiary formation, being of freshwater and brackish origin (p. 117 of my Geological Observations on South America). Hence these beds are of unknown age, probably younger than the old tertiary and older than the superficial beds in which Macrauchenia was found.”

1853. Tanks and hose. Gardeners’ Chronicle and Agricultural Gazette no. 19 (7 May): 302. F1807 C R D would be glad of information on the following point, and it might be useful to others as well as himself. He intends making a large tank, and has three others, much smaller but deeper tanks, standing on the same level or a little lower, which he wants to have the power

244

1855. On the power of icebergs to make rectilinear uniformly-directed grooves

of filling from the large tank. The distance between the two furthest tanks is about 180 feet, but not in a quite straight line; the deepest tank is 21 feet. Now, can any one tell him whether a syphon made of Burgess and Keys’ canvas hose, lined and coated with gutta percha,1 or of any other material, would practically answer? What bore should the syphon have, to convey in the course of 10 or 12 hours 3000 gallons of water?2 (It depends altogether on the difference of level between the water in the one tank and that in the other. The syphon may be filled easily, if one end be placed in one tank, and a hand garden syringe tied to the other end, which would soon pump it full.)

1 2

A kind of rubber, used to insulate the first undersea telegraphy cable in 1850. See CCD5: 138. There was one response in Gardeners’ Chronicle, no. 20, 14 May 1853, p. 318.

1855. On the power of icebergs to make rectilinear uniformly-directed grooves across a submarine undulatory surface. By C. Darwin, Esq., Vice-Pres. R. S., F. G. S. The London, Edinburgh and Dublin Philosophical Magazine 10 (August): 96–8. F16811 Having been induced to believe, with many geologists, that certain continuously scored and polished surfaces of rock were due to icebergs, and not to glaciers, I have nevertheless always felt much difficulty in understanding how long, rectilinear scratches, running in one given direction across an undulatory surface, could have been thus formed.* Others have felt this same difficulty, and it has been advanced as an insuperable difficulty by the opponents of iceberg action. The following considerations, though possessing little or no novelty, have in my own case removed the difficulty. But first, to give one instance of such scratches, I may quote a passage from Agassiz,† who, in describing the state of the surface near Lake Superior, says, “nothing is more striking in this respect than the valleys or depressions of the soil running E. and W., where we see the scratches crossing such undulations at right angles, descending along the southern gentle slope of a hill, traversing the flat bottom below, and rising up the next hill south in unbroken continuity.” He proceeds to state that the scratches run up even steep northern slopes, though the southern faces of the hills are generally rugged. A glacier driven straight forwards over its unequal bed would perfectly account for these facts; but not so, at first appearance, floating ice, whether that of coast-ice or of icebergs. For such masses being borne along on the level ocean, would, when driven on shore or against a submarine hill, be deflected, as it might be thought, from their course, and mark the rocks horizontally or nearly so,—some allowance being made for the rise and fall of the tide. And although during either the submergence or emergence of the land, the whole surface of a mountain might become thus marked, yet the successive scores at each level would all be nearly horizontal. No doubt short inclined grooves might be formed by masses of ice being driven by gales up the beach; but as sea-shores run in every possible direction, *

Communicated by the Author.

†

Lake Superior, its Physical Character, &c., by L. Agassiz, p. 406. [Agassiz 1850.]

1855. On the power of icebergs to make rectilinear uniformly-directed grooves

245

it is obvious that such grooves could follow no uniform course, nor could they be of any considerable length; hence grooves thus made would not be comparable with those now under discussion. The plasticity of glaciers, as shown by the manner in which they immediately expand after passing through gorges, and in which they mould themselves to every sinuosity and prominence in their beds, is now, thanks to the labours of a few eminent men, familiarly known to every geologist. It is asserted by |97| some authors that glacier ice is most plastic when most charged with water, and the lower part of an iceberg must be water-logged. Again, a glacier, for instance of 1000 feet in thickness, must press on its bed with the whole immense weight of the superincumbent ice; but in an iceberg 1000 feet thick, as the whole floats, there will of course be no pressure on a surface exactly level with its bottom, and if driven over a prominence standing up at the bottom of the sea some 50 or 100 feet above the basal line of the berg, only the weight of as much ice as is forced up above the natural level of the floating mass, will press on the prominence. It may therefore, I think, be concluded that an iceberg could be driven over great inequalities of surface easier than could a glacier. That the weight of a comparatively thin sheet of ice is sufficient to groove rocks, we may infer from the case described by Sir C. Lyell of the scores made by the packed shore-ice on the coast of the United States. That icebergs do not break up when grounded, as à priori might have seemed probable, is obvious from the simple fact of their having been often observed in this condition in open turbulent seas. Let anyone who has witnessed the crash of even so small an object as a ship, when run into by another having only a barely perceptible movement, reflect on the terrific momentum of an iceberg, some mile or two square, and from 1000 to 2000 feet in thickness, when, borne onwards by a current of only half a mile per hour, it runs on a submarine bank: may we not feel almost certain, that, moulding itself like a glacier (of which it originally was a portion), but owing to its water-logged state and little downward pressure moulding itself more perfectly than a glacier, it would slide straight onwards over considerable inequalities, scratching and grooving the undulatory surface in long, straight lines? In short, if in our mind’s eye we look at an iceberg, not as a rigid body (as has hitherto been always my case) which would be deflected or broken up when driven against any submarine obstacle, but as a huge semi-viscid, or at least flexible mass floating on the water, I believe much of the difficulty will be removed which some have experienced in understanding how rectilinear grooves could be formed continuously running, as if regardless of the outline of the surface, up and down moderately steep inequalities, now existing as hills on the land. It should be borne in mind that the course of deeply-floating icebergs is determined by the currents of the sea, and not, as remarked by Scoresby, by the shifting winds; and as the currents of the sea are well known to be definite in their course, so will be the grooves formed by current-borne icebergs. It is indeed difficult to imagine any difference between the effect on the underlying surface, of a glacier propelled by its gravity, and that of a mountainous island of ice |98| driven onwards by an oceanic current, except that the iceberg would perhaps have the power, from the causes above specified, of even more closely moulding itself, and, as it were, of flowing straight over submarine obstacles, than has a glacier on the dry land.

246

1855. Does sea-water kill seeds?

One other point is perhaps worth considering. I have elsewhere* endeavoured to show that the action of coast-ice and of icebergs must be considerably different in transporting boulders; the worn stones on the beach being imbedded in coast-ice, and fragments of rock which had originally fallen on the parent-glacier being carried by icebergs as on rafts. But when we reflect that icebergs are driven onwards year after year in certain definite directions by the currents of the sea,—that they float so deeply as to have been seen aground at the depth of 1500 feet,—that when stranded they must (as I conceive) mould themselves to the inequalities of the bottom and slide some distance over it,—it can hardly be doubted that they also must, like glaciers on the land, push in certain determinate directions moraines before them. Although a fragment of rock or an irregularly formed moraine may by any one iceberg be propelled for only a very short distance, yet in the course of years the transportal can hardly fail to become far extended, the boulders being rolled over large inequalities of surface, and even up heights by the action of successively smaller bergs: an abyss, however, deeper than the deepest-floating iceberg would, of course, absolutely stop this rolling or pushing action. Finally, in the case of every mass of erratic boulders, we have now to determine, and I believe hereafter it will be so determined, whether they were transported by glaciers or by floating ice, and in this latter case whether imbedded in coast-ice, strewed on the surface of icebergs, or pushed onwards as a subaqueous moraine.

1

This was originally intended as an appendix to Ramsay 1852. See CCD5: 327–8. CD maintained, against increasing evidence of the power of glaciers to produce parrallel grooves (e.g. Agassiz 1850), that icebergs had sufficient viscosity to ‘mould themselves to the inequalities of the bottom and slide some distance over it’.

1855. Does sea-water kill seeds? Gardeners’ Chronicle and Agricultural Gazette no. 15 (14 April): 242. F16821 I have begun making some few experiments on the effects of immersion in sea-water on the germinating powers of seeds, in the hope of being able to throw a very little light on the distribution of plants, more especially in regard to the same species being found in many cases in far outlying islands and on the mainland. Will any of your readers be so kind as to inform me whether such experiments have already been tried? And, secondly, what class of seeds, or particular species, they have any reason to suppose would be eminently liable to be killed by sea-water? The results at which I have already arrived are too few and unimportant to be worth mentioning. Charles Darwin, Down, Farnborough, Kent, April 11.

1

*

CD had long disbelieved in land bridges connecting oceanic islands with continents to explain the distribution of species. See CCD3. In 1855 he began a series of researches to uncover how animals and plants could be transported by natural means across oceans. He focused on soaking seeds in salt Transactions of the Geological Society, vol. vi. (2nd series) 1841. p. 430. [Darwin 1842, F1661 (p. 147).]

1855. Does sea-water kill seeds?

247

water for periods long enough for currents to transport them to distant islands and still germinate. These researches were part of CD’s vast and wide-ranging research programme in support of his theory of evolution.

1855. Does sea-water kill seeds? Gardeners’ Chronicle and Agricultural Gazette no. 21 (26 May): 356–7. F1683 As you have done me the honour to notice favourably my wish to ascertain experimentally the power of resistance in seeds to the injurious action of sea-water, you may perhaps like to have a report. As such experiments might naturally appear childish to many, I may be permitted to premise that they have a direct bearing on a very interesting problem, which has lately, especially in America, attracted much attention, namely, whether the same organic being has been created at one point or on several on the face of our globe. As geologist I feel a special interest on the possibility of plants being transported by sea to distant islands, owing to the great influence which it is very obvious the views of the late ever-lamented Edward Forbes have had on the subsequent writings of botanists and zoologists. Forbes, as is well known, boldly supposed that the north coast of Spain had formerly been directly continuous with Ireland, and he extended the continent of Europe as far as and beyond the Azores.1 To imagine such enormous geological changes within the period of the existence of now living beings, on no other ground but to account for their distribution, seems to me, in our present state of ignorance on the means of transportal, an almost retrograde step in science—it cuts the knot instead of untying it. Weighty objections might, I think, be urged against Forbes’ hypothesis as applied in the above and many other cases, but this is not the proper place to discuss such a question. As I had not the least notion when I began, whether or not the seeds would be all killed by a single week’s immersion, I at first took only a few, selecting them almost by chance from the different great natural families; but I am now trying a set chosen on philosophical principles by the kindness of Dr. Hooker.2 The sea-water has been made artificially with salt procured from Mr. Bolton,3 146, Holborn Bars, which has been tested by better chemists than men,4 namely, by numerous sea animals and algæ having lived in it for more than a year. The seeds were placed in separate bottles, holding from 2 to 4 oz. each, out of doors in the shade: the mean temperature has during the period been about 44°, rising during one week to a mean of nearly 48°. Most of the seeds swelled in the water, and some of them slightly coloured it, and each kind gave to it its own peculiar and strong odour. The water in which the Cabbage and Radish seeds were placed became putrid, and smelt offensively in a quite extraordinary degree; and it is surprising that any seeds, as was the case with the Radish, could have resisted so contaminating an influence; as the water became putrid before I had thought of this contingency, it was not, and has never been, renewed. I also placed seeds in a quart bottle in a tank filled with snow and water, to ascertain whether the seeds kept at the temperature of 32° would better resist the salt water; this water, like that in the small bottles, to my surprise became turbid and smelt rather offensively. In the following list I have no reason to suppose, except in the cases where so stated, that the seeds have endured their full time.

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1855. Does sea-water kill seeds?

(1) Seeds of common Cress (Lepidium sativum) have germinated well after 42 days’ immersion; they give out a surprising quantity of slime so as to cohere in a mass. (2) Radishes have germinated less well after the same period. (3) Cabbage seed: after 14 days’ immersion only one seed out of many came up; I think this is rather strange considering that the Cabbage is a sea-side plant; in the ice-cold salt water, however, several have come up after 30 days’ immersion. (4) Lettuce seed has grown well after 42 days; (5) of Onion seed only a few have germinated after the same period; (6) Carrot and (7) Celery seed well after the 42 days; (8) Borago officinalis,5 (9) Capsicum,6 (10) Cucurbita ovifera,7 have germinated well after 28 days’ immersion; the two latter, rather tender kinds, were also tried in the ice-cold water, and have germinated after 30 days’ immersion. (11) Savory, or Satureja, has grown somewhat less well after 28 days. (12) Linum usitatissimum:8 only one seed out of a mass of seeds (which gave out much slime) came up after the 28 days, and the same thing happened after 14 days; and only three seeds came up after the first seven days’ immersion, yet the seed was very good. (13) Rhubarb, (14) Beet, (15) Oracle,9 or Atriplex, (16) Oats, (17) Barley, (18) Phalaris canariensis,10 have all germinated excellently after 28 days; likewise these six latter after 30 days in the ice-cold water. (19) Beans and (20) Furze, or Ulex: of these a few survived with difficulty 14 days; the Beans were all killed by 30 days in the ice-cold water. (21) Peas germinated after seven |357| days, but were all dead after 14 days’ immersion out of doors, and likewise after 30 days in the ice-cold water. (22) Trifolium incarnatum11 is the only plant of which every seed has been killed by seven days’ immersion; nor did it withstand 30 days in the ice-cold salt water. (23) Kidney Beans have been tried only in the latter water, and all were dead after the 30 days. As out of these 23 kinds of seed, selected almost at hap-hazard, the five Leguminosæ12 alone have as yet been killed (with the exception of the Cabbage seed, and these have survived in the ice-cold water), one is tempted to infer that the seeds of this family must generally withstand salt water much worse than the seeds of the other great natural families; yet from remarks in botanical works, I had expected that these would have survived longest. It has been really curious to observe how uniform, even to a day, the germination has been in almost every kind of seed, when taken week after week out of the salt water, and likewise when compared with the same seeds not salted—all of course having been grown under the same circumstances, namely, in glasses on my chimney-piece, so that the seeds from the day of being planted have been always under my eye. The germination of the Rhubarb and Celery alone has been in a marked degree altered, having been accelerated. With respect to Convolvulus tricolor,13 not included in the above list, I may mention that many of the seeds germinated and came out of their husks, whilst still in the salt water, after six or seven days’ immersion. To return to the subject of transportal, I may state that in “Johnston’s Physical Atlas”14 the rates of 10 distinct currents in the Atlantic (excluding drift currents) are given, and the average of them is 33 nautical miles per diem; hence in 42 days, which length of immersion seven out of the eight kinds of seed as yet tested have already stood, a seed might be readily carried between 1300 and 1400 miles. I will conclude this too lengthy communication by observing that all the 40–50 seeds which I have as yet tried sink in sea-water; this seems at

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first a fatal obstacle to the dissemination of plants by sea currents; but it may be doubted whether most seeds (with the exception of the winged kinds), when once shed, are so likely to get washed into the sea as are whole or nearly whole plants with their fruit by being carried down rivers during floods, by water-spouts, whirlwinds, slips of river-cliffs, &c., continued during the long lapse of geologically modern ages. It should be borne in mind how beautifully pods, capsules, &c., and even the fully expanded heads of the Compositæ15 close when wetted, as if for the very purpose of carrying the seed safe to land. When landed high up by the tides and waves, and perhaps driven a little inland by the first inshore gale, the pods, &c., will dry, and opening will shed their seed; and these will then be ready for all the many means of dispersal by which Nature sows her broad fields, and which have excited the admiration of every observer. But when the seed is sown in its new home then, as I believe, comes the ordeal; will the old occupants in the great struggle for life allow the new and solitary immigrant room and sustenance? Charles Darwin, Down, Farnborough, Kent, May 21.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Forbes 1846. See CCD5: 331–4. Joseph Dalton Hooker. William Bolton was a dealer in chemicals. A misprint for ‘man’. Borage or starflower. A genus of plants from the nightshade family. A gourd. Linseed or flax. Misspelling of orache. Canary-grass. Crimson clover. Plants of the pea or bean family. Dwarf morning glory. Johnston 1848. Aster, daisy or sunflower family.

1855. Lizard’s eggs. Gardeners’ Chronicle and Agricultural Gazette no. 21 (26 May): 360. F1808 If any of your readers could obtain for me some eggs of the Lacerta agilis,1 I should be greatly obliged. Lizards are most widely distributed, and I want to ascertain whether the eggs will float in sea-water, and, if so, whether they will retain their vitality. A reward of a few shillings (which I would gladly repay as well as postage) offered to schoolboys, would perhaps get these eggs in the proper districts collected. Ch. Darwin, Downe, Farnborough, Kent.

1

Sand Lizard, formerly common in coastal dunes and heaths. See CCD5: 337–8.

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1855. Shell rain in the Isle of Wight

1855. Nectar-secreting organs of plants. Gardeners’ Chronicle and Agricultural Gazette no. 29 (21 July): 487. F1684 In the account compiled by Gärtner (“Beiträge zur Kenntniss der Befruchtung,” p. 75, 1844)1 of the various organs in plants from which nectar is secreted, no mention is made of the stipulæ of the leaves of the common Vetch and Bean. On two occasions I have observed hive bees by the thousands industriously visiting the little dark (but sometimes colourless) glands on the under side of the stipulæ of the Vetch. On a hot day, on each gland a minute drop of nectar may be seen almost with the naked eye, and which is sometimes so large as to be just perceptibly sweet. I have seen the hive and another species of bee, a moth, ants, and two kinds of flies, sucking these drops. The hive bee never once even looked at the flowers, but attended solely to the stipulæ; whereas, at the very same time, two kinds of humble bee were sucking the flowers, and never visited the stipulæ. I noticed the hive bees on three successive hot days thus employed; but on the overcast morning of the 12th, after the previous very rainy day, not one was to be seen at mid-day, but numbers of humble bees were sucking the flowers: at 4 o’clock P.M., however, after some hot sunshine, a little glittering drop of nectar studded every gland, and the hive bees, by their mysterious means, had found it out, and were swarming all over the field. The fact of nectar being secreted by an organ quite distinct from the flower (though known in other cases) seems to me of some little interest, as showing that those botanists cannot be correct who believe that nectar is a special secretion for the purpose of tempting insects to visit flowers, and thus aid in their fertilisation. No one probably who has attended to this subject will dispute that insects in very many cases do thus aid the act of fertilisation; but we must, I think, look at the nectar as an excretion which is only incidentally (as is so often done by nature) made use of for a further but most important object. C. Darwin, Down, Farnborough, Kent.

1

Karl Friedrich Gärtner (1772–1850), German physician and botanist. Gärtner 1844. On this letter and CD’s notes and observations on the habits of bees see CCD5: 383.

1855. Shell rain in the Isle of Wight. Gardeners’ Chronicle and Agricultural Gazette no. 44 (3 November): 726–7. F1685 I earnestly hope that “C.” of Winchester1 will give some more particulars regarding the fall of shells at Osborne: Were any of the shells living? Over how wide an area did they fall? During how long a time are they believed to have fallen? At what hour and on what day? Did only one kind of shell fall? I hope “C.” will forgive me for suggesting to him how very desirable it is that so extraordinary and very interesting a fact should be authenticated by the narrator’s name. It is really almost a duty towards the science of natural history to do so. Were the Zua identified by any good conchologist?—this seems to me an important point. C. D., Down.

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(The Zua was very obligingly identified by Dr. Baird2 |727| of the British Museum. Our correspondent’s name is C. Winchester; he is the intelligent foreman in the Royal Gardens at Osborne, and will, we hope, furnish the additional information asked for.)3

1

2 3

C. Winchester, foreman in the Royal Gardens at Osborne, Isle of Wight, asked for the identity of shells that fell during a thunderstorm in Gardeners’ Chronicle, no. 43, 27 October 1855, p. 710. The editor identified them as Zua lubrica (snails then known as Common Varnished Shells) common in northern Europe, and asked whether any correspondent could suggest where ‘the Zua can have been found by the storm in sufficient quantity?’ See CCD5: 491–2. William Baird (1803–72), Scottish physician and assistant in the zoological department of the British Museum, 1841–72. Winchester replied in Gardeners’ Chronicle, no. 45, 10 November 1855, p. 743. He stated that many were still alive, the area covered was at least 400 square yards and all were of the same type. See CCD5: 492, note 2.

1855. Vitality of seeds. Gardeners’ Chronicle and Agricultural Gazette no. 46 (17 November): 758. F16861 Several statements have been published on the number of years during which seeds preserved in a dry state have retained their power of germinating, but much less seems to be known in regard to seeds lying naturally near the surface of the ground; therefore you may, perhaps, think the following case, though very far from a striking one, worth publishing. An arable field 15 years ago was laid down in pasture; nine years ago last spring, a portion was deeply ploughed up and planted with trees, and in the succeeding summer, as far as I can trust my memory, plenty of Charlock,2 which abounds in this neighbourhood, came up; but if my memory plays me false the case will prove so much the stronger. From being badly ploughed the whole of the land in the course of the year became covered with Grass and coarse weeds, and has remained so ever since, and the trees have now grown up. It is very improbable, from the well known habits of the Charlock, that it could have grown in the little wood after the first year or two; and though almost daily visiting it I have not noticed a plant. But this spring I had some Thorn bushes pulled up, and it was so done that not more than one or two (I speak after comparison) hand’s breadth of earth was turned up. To my surprise in July I happened to observe on one of the little patches of earth no less than six dwarf Charlock plants in flower; on each of two other patches three plants; and on the fourth one plant. This made me on July 21st have three separate plots of ground, each 2 feet square, in different rather open parts of the wood, cleared of thick Grass and Weeds, and dug one spit deep. By August 1st many seedlings had come up, and several of them seemed to be cruciferous plants;3 so I marked with little sticks 11 of them on one of the beds; six on the second bed; and five on the third bed; two or three died, all the rest grew up and proved to be Charlock. I can state positively that no Charlock was growing near these beds; and I do not believe there was any within a quarter of a mile, as the little wood is surrounded by Grass land. Now, to my mind, this seems good evidence that the Charlock seed had retained its vitality within a spit’s depth of the surface during at least eight or nine years. In most cases, when plants spring up unexpectedly, as when

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a wood has been burnt down, it is not possible to feel sure (as has been remarked to me by Dr. Hooker) that the seeds had not been strewed about during the last year or two by birds or other means. Had the several Charlock plants come up on one spot alone, I should have thought that some accident had brought a pod there, and that I had overlooked during the previous years a few Charlock plants, but it seems to me improbable in the highest degree that on each of the 6 plants,4 taken by simple hazard, several (in one of the cases 11) seeds should have been dropped by some unknown agency, having been brought from a quarter of a mile distance. But if when the land was ploughed, 9 years ago (or when arable, 15 years ago) the whole was, as I believe, almost covered by Charlock, the seed would have been scattered everywhere, ready to spring up at whatever point the land might subsequently be stirred up. I will only further remark that the power in seeds of retaining their vitality when buried in damp soil may well be an element in preserving the species, and, therefore, that seeds may be specially endowed with this capacity; whereas, the power of retaining vitality in a dry and artificial condition must be an indirect, and in one sense accidental, quality in seeds of little or no use to the species. Charles Darwin, Down, Nov. 13.

1 2 3 4

This letter was a response to an editorial in the Gardeners’ Chronicle no. 45 (10 November 1855) pp. 739–40. See [Darwin] 1844, F1918 (p. 177) and CCD5: 502. Wild mustard. A large family of plants with four-petaled flowers, including mustards, cabbages, broccoli, turnips and cresses. CD pointed out in his 21 November letter to Gardeners’ Chronicle that ‘6 plants’ was a misprint and should have read ‘6 plots of ground’.

1855. Effect of salt-water on the germination of seeds. Gardeners’ Chronicle and Agricultural Gazette no. 47 (24 November): 773. F1687 As you have published notices by Mr. Berkeley and myself1 on the length of time seeds can withstand immersion in sea-water, you may perhaps like to hear, without minute details, the final results of my experiments. The seed of Capsicum, after 137 days’ immersion, came up well, for 30 out of 56 planted germinated, and I think more would have grown with time. Of Celery only 6 out of some hundreds came up after the same period of immersion. One single Canary seed grew after 120 days, and some Oats half germinated after 120; both Oats and Canary seed came up pretty well after only 100 days. Spinach germinated well after 120 days. Seed of Onions, Vegetable Marrow, Beet, Orache and Potatoes, and one seed of Ageratum mexicanum2 grew after 100 days. A few, and but very few, seed of Lettuce, Carrot, Cress, and Radish came up after 85 days’ immersion. It is remarkable how differently varieties of the same species have withstood the ill effects of the salt water; thus, seed of the “Mammoth White Broccoli” came up excellently after 11 days, but was killed by 22 days’ immersion; “early Cauliflower” survived this period, but was killed by 36 days: “Cattell’s Cabbage” survived the 36 days, but was killed by 50 days; and now I have seed of the wild Cabbage from Tenby growing so vigorously after 50 days, that I am sure that it will survive a considerably

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longer period. But the seed of the wild Cabbage was fresh, and some facts show me that quite fresh seed withstands the salt water better than old, though very good seed. With respect to an important point in my former communication of May 26th, permit me to cry peccavi;3 having often heard of plants and bushes having been seen floating some little distance from land, I assumed—and in doing this I committed a scientific sin—that plants with ripe seed or fruit would float at least for some weeks. I always meant to try this, and I have now done so with sorrowful result; for having put in salt-water between 30 and 40 herbaceous plants and branches with ripe seed of various orders, I have found that all (with the exception of the fruit of evergreens)4 sink within a month, and most of them within 14 days. So that, as far as I can see, my experiments are of little or no use (excepting perhaps as negative evidence) in regard to the distribution of plants by the drifting of their seeds across the sea. Can any of your readers explain the following sentence by Linnæus, pointed out to me by Dr. Hooker, “Fundus maris semina non destruit”?5 Why does Linnæus say that the bottom of the sea does not destroy seeds? The seeds which are often washed by the Gulf Stream to the shores of Norway, with which Linnæus was well acquainted, float, as I have lately tried. Did he imagine that seeds were drifted along the bottom of the ocean? This does not seem probable, from the currents of the sea, at least many of them, being superficial. Charles Darwin, Down, Nov. 21.—P.S. In my communication on Charlock seed lately printed by you, there is a misprint of “6 plants” for “6 plots of ground,” which makes nonsense of the sentence.6

1 2 3 4 5 6

See Darwin 1855, F1683 (p. 247). Darwin later published a more detailed account of these experiments in Darwin 1857, F1694 (p. 258). See CCD5: 506. Floss flower. Latin, meaning ‘I have sinned’. A misreading of ‘Euonymus’. See CD’s letter in Gardeners’ Chronicle no. 48 (1 December): 789, F1688 (p. 253). ‘Maris fundus non destruit Semina.’ (‘the bottom of the sea does not destroy seeds’) Linnaeus 1751. Philosophia Botanica, Sexus, 132. See CD’s letter in Gardeners’ Chronicle no. 46 (17 November): 758, F1686 (p. 251).

1855. Effect of salt-water on the germination of seeds. Gardeners’ Chronicle and Agricultural Gazette no. 48 (1 December): 789. F1688 In my communication of last week1 it is printed by mistake that the fruit of “evergreens,” instead of the fruit of the Euonymus,2 did not sink after immersion in salt water during a month. I may add that I think that the experiments on immersion of seeds in sea water have some little interest, as showing that we cannot infer from seeds of certain orders long retaining their power of germination in a dry condition, that these same seeds will retain it under different conditions. Thus the Solaneæ and Leguminosæ are believed to keep longest when preserved in the ordinary way in a dry state, and the Solaneæ seem generally to resist well the salt water, whereas most Leguminosæ resist much worse, as I have shown in your number of the 26th May,3 than other orders. I have lately tested this conclusion with quite fresh seeds of Trifolium

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incarnatum4 and Kidney Beans. Indeed with respect to some Leguminosæ I have reason to believe that a short immersion in plain water will kill them. So with respect to the subject lately discussed in your columns, namely how long seeds will remain alive when buried in damp earth, I do not see that any safe conclusion can be drawn from the length of time during which the same seeds can retain their vitality whilst dry. C. Darwin, Down, Bromley, Kent.

1 2 3 4

Darwin 1855, F1687 (p. 252). Spindles, a genus of deciduous and evergreen shrubs and small trees. Darwin 1855, F1683 (p. 247). Crimson clover.

1855. Longevity of seeds. Gardeners’ Chronicle and Agricultural Gazette no. 52 (29 December): 854. F1689 As you have lately published such full and interesting details on the case of the long entombed Raspberry seeds,1 you may like to hear that a somewhat similar instance has been observed on the Continent. Gærtner (Versuche über die Bastarderzeugung, s. 157)2 states on the authority of Jouannot3 that seeds from the graves of ancient Gauls, of the date of the introduction of Christianity (probably at the time of Clodowig4 in the third or fourth century A.D.) germinated and produced Heliotropium vulgare,5 Centaurea cyanus,6 and Trifolium minimum.7 Gærtner gives, as reference, Froriep Notizen, B. XLIII., No. 946, p. 348.8 It seems that no known botanist looked to the correctness of these names. C. Darwin.

1 2 3 4 5 6 7 8

Gardeners’ Chronicle, no. 45, 10 November 1855, pp. 739–40. See CCD5: 532–3. Gärtner 1849, pp. 157–8. François René Bénit Vatar de Jouannet (1765–1845), French statistician and archaeologist. Clodowig = Clovis I (c. 466–511), King of the Franks. European heliotrope (Heliotropium europaeum L.). Cornflower. Yellow clover (Trifolium campestre). Robert Friedrich Froriep (1804–61), German physician and anatomist who edited Notizen aus dem Gebiete der Natur- und Heilkunde; No. 946, March 1835, p. 346, cited Jouannet as the source.

1855. Seedling fruit trees. Gardeners’ Chronicle and Agricultural Gazette no. 52 (29 December): 854. F1690 As several different statements have been published on how far the different varieties of our fruit trees produce seedlings like their parents, I think very interesting information might be given by some few of your correspondents who may have carefully sown named seeds and have noted the result. Jourdan (in the “Mémoires de l’Acad. de Lyons,” vol. ii., p. 94, 114)1 states most positively that he has tried repeatedly, and that all the many seedlings which he raised from the same variety of fruit tree resembled each other in foliage and general manner

1856. [Typical list of cirripedia]

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of growth as perfectly as do the young plants of any wild species whatever; and therefore that they differed from the seedlings of every other variety of the same fruit tree. Hence, also, as he asserts, the seedlings of one variety can never be confounded by an experienced eye with those of another variety, being as distinct as were their parents. Moreover, he states that the fruit of seedling Pears and Apples, though differing greatly in size, succulency, and flavour from those of their parents, yet resemble them in the more important characters of form and in the nature of their seeds. On the other hand Van Mons2 asserts that he sometimes raised from the seed of one variety of Pear a quite distinct kind; but it now appears that Van Mons was careless in marking the varieties sown.3 If any one can give accurate information on this curious subject, I hope that he will be so kind as to take the trouble to do so; and will give, as far as he can, some idea what proportion of seedlings are produced which resemble their parents in foliage and general habit; for if seedlings differ from their parents only in a few rare instances, this might perhaps be attributed to an accidental cross from some neighbouring tree. Is it known whether some varieties of Pears and Apples tend to produce truer offspring than other varieties? Plums are said to come very true. Mr. Rivers,4 and possibly others, could probably give very interesting details on this head. C. Darwin.

1 2 3 4

Claude Thomas Alexis Jordan (1814–97), French botanist. Jordan 1852. See CCD5: 533–4. Jean Baptiste van Mons (1765–1842), Belgian botanist and professor of chemistry and agronomy at Louvain (1817–30). Mons 1835–6. Decaisne 1855. Thomas Rivers, nurseryman who specialised in fruit-trees and roses. CD cited him frequently in Variation.

1856. [Typical list of cirripedia]. In [On Typical Objects in Natural History]. Report of the twenty-fifth meeting of the British Association for the Advancement of Science; held at Glasgow in September 1855. London: John Murray, p. 121. F1977 The following list for the Cirripedia1 is communicated by C. Darwin, Esq. Subclassis Cirripedia. Ordo I. Thoracica. Pollicipes mitella (best type for the order). Fam. 1. Balanidæ (sessile Cirripeds). Subfam. 1. Balaninæ.......... 2. Chthamalinæ ......

Fam. 2. Verrucidæ.......... 3. Lepadidæ (pedunculated Cirripeds)........

Balanus tintinnabulum. ——porcatus........ B.2 Chthamalus stellatus .. B. Catophragmus polymerus (as connecting Balanidæ with Lepadidæ). Verruca stromia ...... B Lepas anatifera ...... B

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Ordo II. Abdominalia. Crypiophialus minutus. Ordo III. Apoda. Proteolepas bivincta.

1 2

Barnacles. ‘B’ indicates British species.

1856. Cross breeding. Gardeners’ Chronicle and Agricultural Gazette no. 49 (6 December): 806. F1691 I have been lately collecting all the evidence which I can get from the observation of others and my own, on the natural crossing of varieties of plants. The evidence in regard to Leguminous plants is curiously conflicting, but preponderates against their ever crossing without artificial aid.1 I should esteem it a singular favour if any of your correspondents would give in your paper or send me any evidence showing either that Leguminous crops, when grown close together, do sometimes cross; or, on the other hand, that they may invariably be grown close together without any chance of deterioration. Charles Darwin, Down, Bromley, Kent.2

1 2

See Natural selection, pp. 69–71. Darwin 1856, F1692 is an almost identical reprint of this letter. No replies have been found in Gardeners’ Chronicle. See CCD6: 296.

[Darwin, C. R.] 1856–7. [Announcement of the award of a Royal Medal to Sir John Richardson.] Proceedings of the Royal Society of London 8: 257–8. F1936 Your Council have awarded one of the Royal Medals to Sir John Richardson.1 His claims to that honour as a most distinguished naturalist and scientific traveller, will I am sure be generally admitted. Sir J. Richardson’s earliest work on Zoology appeared about the year 1823, but his first great work was published in 1829, namely the ‘Fauna BorealiAmericana,’2 in which he has described the Quadrupeds and Fishes of the Arctic Regions, and with Mr. Swainson’s3 aid, the Birds; the merits of this work, in the very accurate descriptions of the species, in the great amount of information on their habits and ranges, are admitted to be of the highest order. Since that period Sir J. Richardson has published largely on various branches of zoology, physical geography, and meteorology. His Reports to the British Association, on the Fishes of New Zealand and of China, are extremely interesting under many points of view. Another Report to the same body on the General Zoology of North America, is a most valuable contribution to science. His later works, which here must be more particularly considered, are the ‘Zoology of the Voyages of the Terror and of the

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Herald,’4 in which he has described the Fishes and Reptiles collected during those expeditions, and given an account of some of the great extinct mammifers of the Arctic countries, with very interesting observations on their ancient relations and ranges. He has also lately contributed to the Geological |258| Journal a valuable paper, in which he has made known the presence of tertiary strata abounding with vegetable remains, in districts now rendered sterile by the extreme cold. Altogether I think there can be no doubt that the merits of Sir John Richardson, as a philosophical naturalist, are of a very high order. It is not within our province to reward his other claims to distinction; but all will rejoice, that in the conscientious discharge of a delicate and important duty, the Council have been able to bestow a Medal on one, who has earned the applause of all who have watched his career, for his patient endurance and fortitude under incredible hardships in his first Arctic Expedition in company with Franklin, and again for his chivalrous self-devotion in the cause of friendship and science combined, at a period of life when most men resolve to rest from their labours, or at least would hesitate to encounter the fatigues and dangers of a Polar Expedition, the anticipation of which must have been more appalling to one, who had bitter experience of their painful reality. Sir J. Richardson, Accept this Medal as a token of our respect for your scientific labours and character.

1 2 3 4

John Richardson (1787–1865), arctic explorer and naturalist. CD, as a member of the Council, nominated Richardson for a Royal Medal and wrote this announcement of the award. See CCD6: 86. Richardson 1829–37. William Swainson (1789–1855), naturalist and illustrator. Richardson 1844–75 and 1852.

1857. Hybrid Dianths. Gardeners’ Chronicle and Agricultural Gazette no. 10 (7 March): 155. F1693 As you have noticed hybrid Dianths,1 you may like to hear that the summer before last I fertilised a poor single pale red Carnation with the pollen of a crimson Spanish Pink; and likewise a Spanish Pink with the pollen of the same Carnation. I got seed from both crosses in fair number; namely, 77 seed from two pods of the Spanish Pink, and raised plenty of seedlings. In the eyes of a florist they would be, I presume, quite worthless from their straggling habit; but they were showy, and like most hybrids produced during a long time an extraordinary abundance of flowers. They varied somewhat in colour, but in no other respect; and one variety was of a really beautiful pale crimson. Taken in a mass there was no difference between the reciprocal crosses. Not one plant of either lot set a single seed. One plant came up identical with the Spanish Pink; no doubt owing to a few grains of the pollen of the Spanish Pink not having been removed; for Gærtner has shown that this is sometimes the result when a flower is fertilised with mixed pollen. I may add that Gærtner raised many hybrids between various species of Dianthus.2 C. Darwin, Down, Bromley, Kent.

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1

2

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In Gardeners’ Chronicle, 28 February 1857, p. 132, two hybrid Dianthus plants, believed to have grown from seeds from the same seed-capsule, but which had quite different flowers, were discussed. See CCD6: 349–50. Gärtner 1849.

1857. On the action of sea-water on the germination of seeds. By Charles Darwin, Esq., Vice-Pres. R. S., F. L. S. &c. [Read 6 May 1856] Journal of the Proceedings of the Linnean Society of London. Botany 1: 130–40. F1694 During the spring of last year it occurred to me that it would be worth while, in relation to the distribution of plants, to test how long seeds could endure immersion in sea-water, and yet retain their vitality. As far as I knew, this had not been tried by botanists, |131| who would have been far more capable of doing it efficiently than myself; and I now find that M. Alph. DeCandolle,1 in his admirable work, “Géographie Botanique,” regrets that such experiments have not been tried; I think, that had he known even the few facts here to be recorded, some of his opinions on the means of distribution of particular families would have been slightly modified. The Rev. M. J. Berkeley has likewise tested fifty-three different kinds of seeds, and has published a report in the “Gardener’s Chronicle,”* to which periodical I have also sent two brief notices on the same subject.† I intend here to give, with Mr. Berkeley’s kind permission, an account of our joint experiments. I may premise, that not knowing, at first, whether the seeds would endure even a week’s immersion, I selected a few by simple chance, taking, however, the seeds of different families; subsequently I have been aided by suggestions from Dr. Hooker. I must briefly describe how my experiments were tried: the seeds were placed in small bottles, each holding two or three ounces of salt water, carefully made according to Schweitzer’s2 analysis: as both algæ and marine animals have, as is well known, long survived in water thus made, there can be no doubt that the experiment was thus fairly tried. Mr. Berkeley sent his seeds to Ramsgate, tied up in little bags and placed in the sea-water, daily renewed; and they were thus immersed for three weeks, and when partially dried, but still damp, were sent off, but by accident were not unpacked for four days subsequently, so that their total immersion “was equivalent to one of more than a month.” Some of my bottles were put out of doors in the shade, and were exposed to an average weekly temperature of from 35° to 57°; the other bottles were kept in my cellar, and were exposed to much less variation of temperature, viz. to a daily mean average of from 46° to 56°. Further, to test the effect of temperature, I immersed eighteen different sorts of seeds in salt water, in a tank, which, from containing much snow, was for six weeks at the temperature of 32°, slowly rising for the next six weeks to 44°; but the seeds thus tested did not

* †

Sept. 1st, 1855. [Berkeley 1855.] May 26th and Nov. 24th, 1855. [Darwin 1855, F1683 (p. 247) and Darwin 1855, F1687 (p. 252). See also Darwin 1855, F1682 (p. 246).]

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seem to withstand the injurious effect of the salt water better than those exposed to a higher but variable temperature. I may remark, that amongst the eighteen kinds of seeds immersed in the cold salt water, there were seeds of a somewhat tender constitution, as capsicum and vegetable marrow, but the exposure to the cold in no degree injured their germination. In the case of some of the seeds which I first tried, |132| and which were put out of doors, I did not change the salt water for fifty-six days, and it became putrid and smelt offensively to a quite surprising degree, especially the water with the cabbage, radish, cress and onion seed, which also gave out strongly the odour of each kind; so that I thought the putridity would infallibly have been communicated to the seeds; but judging from the seeds of some of the same plants (but not actually from the same lot of seed) placed in salt water often renewed, and likewise kept in the cellar under a less variable temperature, neither the putridity of the water nor the changing temperature had any marked effect on their vitality. Cress seed (Lepidium sativum) and that of Phalaris Canariensis, after twenty-two days’ immersion, were thoroughly dried for a week and then planted; they germinated pretty well, but the seeds themselves of this particular lot were not very good. At first I tried the seeds after each successive week’s immersion, and they germinated at the same period as did seeds of the same kind which had not been salted; celery and rhubarb seed, however, were somewhat accelerated in their germination. Some kinds of seeds, as of Trifolium incarnatum, Sinapis nigra,3 peas, kidney and common beans, swelled much in the salt water, and they generally were killed by a short immersion; but the swollen seeds of Lupinus polyphyllus4 germinated better than those which did not swell. I was surprised to observe that most of the seeds of Convolvulus tricolor germinated after seven days under the salt water and lived for some time in it; as did likewise the fresh seed of Tussilago farfara5 after 9 days; after 25 days I took out some of the young plants of the Tussilago and planted them, and one of them grew: some of the seeds of the garden orache (Atriplex) also germinated under water after 56 days’ immersion, but I failed in raising the seedlings; the other seeds of the same lot of the orache germinated excellently after 100 days’ immersion. The total number of seeds tried by Mr. Berkeley and myself amount only to 87, for unfortunately we happened to select some of the same kinds; in one respect, however, this has been fortunate, for we have thus tested each other’s results, and they accord perfectly as far as they go; the seed of the tomato, however, germinated better after a month’s immersion with Mr. Berkeley than after only 22 days with me; but my seed appeared to be old. And this leads me to remark, that I suspect that fresh seed withstands the salt water better than old, but yet good seed; this was the case with Trifolium incarnatum, Phlox Drummondii,6 |133| and I believe with Sinapis nigra. Of the genus Godetia, Mr. Berkeley found one species was killed by, and another survived, a month’s immersion: but a far more curious case is presented by the varieties of the cabbage; for I found that good seed of the “Mammoth white broccoli” germinated after 11 days’ immersion, but was killed by 22 days; seed of the “early cauliflower” survived 22 days; but was killed by 36 days; “Cattell’s cabbage” germinated excellently after 36 days, but was killed by 50 days; and lastly, fresh seed of the wild cabbage from Tenby germinated excellently after 50 days, very well after 110 days, and two seeds out of some hundreds germinated after 133 days’ immersion.

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Of the 87 kinds of seeds tried, 23 or more than one quarter did not endure 28 days’ immersion: capsicum has endured the trial best, for 30 out of 56 seeds germinated well after 137 days’ immersion: of celery seed after the same period of 137 days, only 6 out of several hundreds germinated. The worst germinators have been dwarf kidney beans and Hibiscus manihot,7 both killed by 11 days’ immersion; common peas were killed by 14 days’; Tussilago farfara germinated under water after 9 days, but the young plants kept alive for some time: the next worse germinators have been Phlox Drummondii, Trifolium incarnatum, Linum usitatissimum, and Sinapis nigra, very few of which survived 15 days’ immersion. From such scanty materials it is, perhaps, rash to draw any sort of deduction in regard to the power of resistance to salt water in the different divisions of the vegetable kingdom; but a few remarks may be permitted. Three out of the 17 Endogens and 20 out of the 70 Exogens were killed by a month or 28 days’ immersion: this fact, together with the marked power of endurance in the Atriplex, Beta, Spinacea, and Rheum, lowly organized exogens, accords with, and is perhaps connected with, the fact, insisted on so much by M. A. DeCandolle, of the wider range of the Endogens and of the lowly organized Exogens, than of the higher Exogens.* The four Solanaceæ and two Umbelliferæ endured the salt water very well, and each included the longest survivor of all the species tried. Ten Compositæ were tried, and only one was killed by a month’s immersion, that is excepting the Tussilago which germinated under water. Eight Cruciferæ were tried, and all withstood the influence well, excepting Sinapis nigra, which |134| was killed by 25 days’ immersion; three of the Cruciferæ survived 85 days: this power of endurance in the seeds of this family is, perhaps, surprising, considering the oil in their seeds. Nine Leguminosæ were tried; these all resisted the salt water badly, with the exception of the hard thin seeds of Mimosa sensitiva,8 which germinated pretty well after 50 days; three species of Lupine seemed just able occasionally to withstand about 36 days’ immersion; the seeds of the other Leguminosæ having all been killed by much shorter periods. I suspect that it is the water, and not the salt, which kills the Leguminosæ; at least I found that a lot of fresh “Thurston Reliance” peas were all killed by 13 days’ immersion in pure water;† and I have been assured that a much shorter immersion will kill kidney beans. Lastly, seven species of the allied families of Hydrophyllaceæ and Polemoniaceæ (six having been selected by Mr. Berkeley) were killed by a month’s immersion, and so great a proportion can hardly be accidental. From the great difference in the powers of resistance to the sea-water in the different families just specified, and even in the varieties of the same species; and from the Leguminosæ being apparently in this respect the tenderest, whereas they are generally believed to keep longer than any other seeds in a dry state, I think we may learn a lesson *

†

Godron in his “Florula Juvenalis,” p. 16, states that the seeds of some plants, as of Atriplex and certain Gramineæ, germinate perfectly in salt-marshes, where they have been immersed during all the winter under salt water. [Dominique Alexandre Godron (1807–80), French botanist, zoologist and ethnologist. Godron 1853.] Loiseleur-Deslongchamps says (Consid. sur les Céréales, Part ii. p. 234) that in wheat put into water the embryo comes out in the course of two days; as Mr. Berkeley’s wheat survived after 30 days’ immersion in sea-water, one may suspect that in this case, the seed would survive longer under sea-water than under fresh water. [Jean Louis Auguste Loiseleur Deslongchamps (1775–1849), French botanist and physician. Loiseleur-Deslongchamps 1843.]

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of caution, not to infer with too much certainty which seeds will endure longest when naturally buried in damp earth, from knowing what kinds will keep best in an artificial state. I had intended trying many more seeds, as I at one time thought that these experiments would have thrown more light on the dispersal of plants than I now think they do. I soon became aware that most seeds, in accordance with the common experience of gardeners, sink in water; at least I have found this to be the case, after a few days, with the 51 kinds of seeds which I have myself tried; so that such seeds could not possibly be transported by sea-currents beyond a very short distance. Some few seeds, however, do float, as I have tried with some of those cast by the Gulf Stream on the coast of Norway. From knowing that timber is often cast on the shores of oceanic islands far from the mainland, and from having met with accounts of floating vegetable |135| rubbish off estuaries, I assumed that plants, with ripe seeds, washed into the sea by rivers, landslips, &c., might be drifted by sea-currents during a period of some weeks. The closing of the capsules, pods, and heads of the Compositæ, &c., when wetted, and their re-opening when cast on shore and dried, the seeds being thus allowed to be driven inland by the first stormy winds, seemed to favour such means of transport. But in putting 34 plants of different orders, with ripe fruit, into salt water, one alone, the Euonymus, floated for a month, being buoyed up by its fruit; the others all sunk in 21 days, some in 5, and several in 7, 9, and 11 days. But I am not sure that I have made the trial fairly, for I kept the floating plants in too warm and dark a place, which might have favoured their decay. Finally I may remark, that the seeds of very few species are, as far as we yet know, all killed by 10 days’ immersion,—that some plants will float for this period,—that the average rate of the ten currents in the Atlantic Ocean, given in Johnston’s “Physical Atlas,”9 is 33 miles per diem (the main Equatorial current running at the rate of 60 miles, and the Cape Stream at 80 miles per diem); and therefore I conclude, under the existing extremely scanty materials for forming any opinion, that some plants might under favourable conditions be transported over arms of the sea 300 or even more miles in breadth; and if cast on the shore of an island not well stocked with species, might become naturalized. In the following list, to save repetition, I have marked the plants tried by Mr. Berkeley, and which germinated after a month’s immersion, with †; when they did not germinate, this is expressly stated. The “cold water” refers to the seeds placed in salt water in the tank with snow. I have arranged the families in accordance with Lindley’s “Vegetable Kingdom.”10 Endogens. (Gramineæ.) Avena (common oats): after 85 days’ immersion germinated excellently; after 100 days some germinated; after 120 days some half-germinated. Hordeum (common barley): germinated well after 28 days, but none after 42 days; in the cold water well after 30 days (†). † Triticum (wheat). Phalaris Canariensis: after 70 days nearly all germinated; in |136| another lot after 85, most of the seeds germinated, but the seedlings died off; after 100 and likewise after 120 days’ immersion, in each case, a single seedling came up.

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Holcus saccharatus: after 36 days germinated fairly; after 50 days all died. † Zea Mays: none germinated after a month’s immersion. † Arum maculatum. † Anomatheca cruenta. † Babiana plicata. † Trichonema pudicum. † Sisyrinchium iridifolium. Canna Indica: after 50 days several germinated, but not very strongly. † Colchicum autumnale: did not germinate. Allium cepa: after 56 days’ immersion, 3 out of 15 germinated; after 82 days in the cold water, most of the seeds grew well; after 100 days, 2 or 3 grew out of about 25 planted (†). † Bulbine annua. † Asphodelus luteus. † Uropetalum serotinum: did not germinate. Exogens Ricinus communis (var. major and minor): both germinated after 36 days. Cucurbita Melopepo (vegetable marrow): germinated after 100 days; of 4 seeds immersed in the cold water for 82 days, 2 germinated. † Cucumis Melo (melon). Cistus (mixed shrubby garden varieties): germinated well after 36 days, and some germinated after 70 days. (Cruciferæ.) Lepidium sativum: after 85 days’ immersion only one out of many germinated; after 56 days 6/57 grew: in the cold water, after 65 days, 4/60 grew. († var., golden cress.) These seeds gave out an astonishing quantity of slime in the salt water. Brassica oleracea, var. “Mammoth white Broccoli:” germinated after 11 days’ immersion, but after 22 days all died. —— —— , var. “Early Cauliflower:” after 22 days, 5 out of 100 germinated; after 36 days all dead. |137| Brassica oleracea, var. “Cattell’s Cabbage:” germinated excellently after 36 days; all dead after 50 days. —— —— , var.growing wild on the Castle Rocks of Tenby; fresh seeds, after 50 days germinated excellently; after 110 days germinated very well; after 133 days only two out of some hundreds germinated (†). † Brassica Rapa (var.yellow turnip). Raphanus sativus: after 85 days, 2/30 germinated; the cold water seemed to be injurious to these seeds, for after only 30 or 50 days all the seeds were dead (var.black radish) (†).

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Erysimum Perowskianum: after 36 days germinated well; after 50 only one seed; after 70 days all dead (†). Matthiola annua: germinated after 28 days; all dead after 54 days. Sinapis nigra: seeds much swollen; germinated after 11 days; all dead after 22 days: fresh seed germinated pretty well after 15 days, but were all killed by 25 days’ immersion. Crambe maritima: after 37 days germinated well. Tropæolum majus: after 37 days nearly all germinated, but after 50 days none did. † Limnanthes Douglasii. Hibiscus Manihot: all were killed by 11 days’ immersion (†). † Malope grandiflora. Papaver somniferum: germinated well after 28 days; was killed by 54 days. Argemone Mexicana: came up excellently after 50 days, and pretty well after 70 days. † Chryseis crocea (germinated very imperfectly after the month). Linum usitatissimum: after 7 and after 14 days only two or three seeds, out of very many, germinated; after 28 only one seed came up; after 42 days not one germinated. These seeds gave out much slime. † Silene compacta. Rheum Rhaponticum: germinated well after 82 days. Atriplex (garden orache): some of the seed germinated under water after 56 days’ immersion; the remaining seed germinated excellently after 100 days. Beta vulgaris: excellently after 100 days (†). Spinacea oleracea: excellently after 70 days; a few after 120 days; all killed by 137 days (†). (Leguminosæ.) Vicia Faba (var. “Johnston’s Wonder”): two out of six lived |138| after 11 days’ immersion; one half-germinated after 14 days; after 22 days all dead: many of these beans swelled greatly. I tried sixty after 28 days and found all dead. None survived 30 days in the cold water. Pisum sativum: after 11 days some germinated; none survived 14 days; none survived 30 days in the cold water. Another lot of fresh seed (“Thurston’s Reliance”) all died after 12 days; none survived 30 days in the cold water. I found 13 days’ immersion in pure water killed these latter fresh peas. († None germinated.) Phaseolus vulgaris (var. “early frame dwarf ”): all died after 11 days’ immersion; after 28 days’ immersion, 80 were planted, but all dead. I tried another lot of fresh seed, but none of them resisted even 10 days’ immersion; nor did they resist 30 days in the cold water: many of these seeds swelled much (†). Trifolium incarnatum: all died after 11 days’ immersion, and after 30 in the cold water. Fresh seed germinated excellently after 5 days’ immersion, well after 12 days, and

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one single seed out of some hundreds germinated after 20 days. These seeds swelled much. Ulex europæus: after 11 days germinated well; after 14 days two germinated; after 28 days all dead. Lupinus polyphyllus: after 22 days, out of seven swollen seeds three germinated; seven others did not swell and were all dead; after 36 days’ immersion one began to germinate and then died. Lupinus luteus (pale var.): after 22 days 4/12 lived; after 36 days’ immersion 3/18 germinated; after 50 days all dead. † Lupinus pubescens germinated after a month, but Mr. Berkeley says the greater number were rotten. Mimosa sensitiva: germinated excellently after 36 days’ immersion, and pretty well after 50 days. Geum coccineum (var. splendens): after 36 days germinated well, and after 70 days one single seed germinated. Saxifraga incurvifolia: did not germinate after 30 days’ immersion. —— aizoides, nor did this species, but the seed was not very good. (Solanaceæ.) Capsicum annuum: after 137 days’ immersion, 30, out of 56 planted, germinated well (†). |139| Solanum tuberosum: germinated excellently after 70 days, well after 100; all dead after 120 days. —— lycopersicum (common tomato): one seed germinated after 22 days’ immersion, the rest were killed by 36 and 50 days’ immersion. († But Mr. Berkeley found that they germinated after a month.) † —— melongena. Convolvulus tricolor: after having been 7 days in the salt water, many of the seeds germinated, and the embryos came out of the husks: of those which did not germinate under water, one germinated after 36 days’ immersion. (Polemoniaceæ and Hydrophyllaceæ.) Gilia tricolor († was killed by a month’s immersion). Phlox Drummondii: of old seed none germinated after 11 days; but of fresh seed, 3 out of many germinated after 15 days, and none after 25 days’ immersion. Eutoca viscida. † None of these were found by Mr. Berkeley to germinate after a month’s immersion. Nemophila insignis. ——— atomaria. ——— maculata. ——— discoidalis.

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Borago officinalis: a few came up after 14 days’ immersion, one after 28 days, and none after 42 days. † Nolana grandiflora. Satureja (common savory): after 42 days, 3 seeds out of many germinated. Campanula Pentagonia († did not germinate after a month’s immersion). † Fedia graciliflora. † Fedia (corn salad). (Compositæ.) Lactuca sativa (common lettuce): after 56 days’ immersion 7/20 of the seed came up; after 85 days only one out of several germinated. Cold water had no marked effect, but after 65 days they germinated rather better than the others (†). † Cichorium Endivia. Galinsoga trilobata: germinated after 22 days. Aster Chinensis (mixed German varieties): germinated after 28 days; all dead after 54 days’ immersion. |140| Ageratum Mexicanum: after 100 days, one seed out of many germinated; at much shorter periods these seeds did not germinate well. Leontodon Taraxacum: germinated excellently after 61 days’ immersion; the seeds were fresh. Tussilago Farfara: fresh seeds being placed in the salt water, after 9 days, many of them germinated under water. After 25 days, I took out some of the young plants and planted them: one grew. The germination of these seeds is the more remarkable, as this is not a sea-side plant. † Monolopia Californica. † Cenia turbinata. † Cosmos luteus: did not germinate after a month’s immersion. Clarkia pulchella: germinated well after 28 days; was killed by 54 days’ immersion. Clarkia pulchella: germinated well after 28 days; was killed by 54 days’ immersion. † Godetia rubicunda. † — — — Lindleyana was killed by a month’s immersion. Apium graveolens (var. “Cattell’s white”): after 137 days only 6 seeds out of some hundreds germinated; after 85 days the seeds germinated excellently; they did not appear to germinate quite so well after 82 days in the cold water (†). Daucus carota: a very few germinated after 85 days; after only 56 days 3/30 grew (†).

1 2

Alphonse de Candolle (1806–93), Swiss botanist, lawyer and politician. Candolle 1855. Edward G. Schweitzer, German physician and chemist, Director of the Royal German Spa, Brighton. CD probably refers to Schweitzer 1839.

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Black mustard (Brassica nigra—(L.)W. D. J.Koch.). Garden Lupin. Coltsfoot. Annual phlox. Sunset hibiscus (Abelmoschus Manihot). Sensitive Brier. Johnston 1848. Lindley 1853.

1857. Mouse-coloured breed of ponies. Gardeners’ Chronicle and Agricultural Gazette no. 24 (13 June): 427. F1695 Mr. Charles Darwin asks if any of our readers will kindly inform him how dun or mousecoloured ponies with a dark stripe down their back are bred. He says:—“The breed is common in Norway, on the banks of the Indus, and in the Malayan Archipelago; and in some respects very interesting in relation to the origin of the domestic horse. Is the peculiar colour thrown from ponies of any other colour, or must one or both parents be dun? Occasionally ponies of this colour have a cross stripe on the shoulder like that on the ass, and likewise bars on the legs. If any one who has bred ponies of this colour would inform me whether these stripes are more distinct in the colt than in aged ponies I should be much obliged. The transverse bars sometimes seen on the legs of the ass are said to be plainest during growth.” Ch. Darwin, Down, Bromley, Kent.1

1

See CCD6: 411. CD discussed this issue in Natural selection, pp. 328–32.

1857. The subject of deep wells. Gardeners’ Chronicle and Agricultural Gazette no. 30 (25 July): 518. F1696 The Subject of Deep Wells has been sometimes discussed in your columns.1 I have a well 325 feet deep, and the 12-gallon bucket actually weighs 40 lbs. For many years I used a chain weighing 232 lbs.; this, with the water, itself 96 lbs., amounts to 481 lbs. I have made an enormous saving of labour by using for the last half year Newall’s patent wire rope.2 Now, will any one have the charity to say from experience whether there could not be a great saving in the weight of the bucket. Would zinc, or gutta percha, or leather serve? The bucket must be strong enough to withstand being occasionally dashed against the side of the well. Or must I stick to my old substantial oaken friend? C. D.

1 2

See Darwin 1852, F1680. (p. 242). Robert Stirling Newall (1812–89), engineer and astronomer, manufactured wire ropes from the 1840s.

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1857. Bees and the fertilisation of kidney beans. Gardeners’ Chronicle and Agricultural Gazette no. 43 (24 October): 725. F1697 Mr. Swayne in the 5th volume of the Horticultural Transactions incidentally speaks of the advantage of artificially fertilising the early Bean.1 Can you tell me to what sort of Bean he refers? (We presume to the Early Mazagan; but we have no special information.) and who has followed this plan, and how has it been effected? My motive for asking is as follows: every one who has looked at the flower of the Kidney Bean must have noticed in how curious a manner the pistil with its tubular keel-pistil curls like a French horn to the left side-the flower being viewed in front. Bees, owing to the greater ease with which they can reach the copious nectar from the left side, invariably stand on the left wing-petal; their weight and the effort of sucking depresses this petal, which, for its attachment to the keel-petal, causes the pistil to protrude. On the pistil beneath the stigma there is a brush of fine hairs, which when the pistil is moved backwards and forwards, sweeps the pollen already shed out of the tubular and curled keel-petal, and gradually pushes it on to the stigma. I have repeatedly tried this by gently moving the wing petals of a lately expanded flower. Hence the movement of the pistil indirectly caused by the bees would appear to aid in the fertilisation of the flower by its own pollen; but besides this, pollen from the other flowers of the Kidney Bean sometimes adheres to the right side of the head and body of the bees, and this can scarcely fail occasionally to be left on the humid stigma, quite close to which, on the left side, the bees invariably insert their proboscis. Believing that the brush on the pistil, its backward and forward curling-movement, its protrusion on the left side, and the constant alighting of the bees on the same side, were not accidental coincidences, but were connected with, perhaps necessary to, the fertilisation of the flower, I examined the flowers just before their expansion. The pollen is then already shed; but from its position just beneath the stigma, and from its coherence, I doubt whether it could get on the stigma, without some movement of the wing petals; and I further doubt whether any movement, which the wind might cause, would suffice. I may add that all which I have here described occurs in a lesser degree with Lathyrus grandiflorus.2 To test the agency of the bees, I put on three occasions a few flowers within bottles and under gauze: half of these I left quite undisturbed; of the other half I daily moved the left wing-petal, exactly as a bee would have done whilst sucking. Not one of the undisturbed flowers set a pod, whereas the greater number (but not all) of those which I moved, and which were treated in no other respect differently, set fine pods with good seeds. I am aware that this little experiment ought to have been repeated many times; and I may be greatly mistaken, but my belief at present is, that if every bee in Britain were destroyed, we should not again see a pod on our Kidney Beans. These facts make me curious to know the meaning of Mr. Swayne’s allusion to the good arising from the artificial fertilisation of early Beans. I am also astonished that the varieties of the Kidney Bean can be raised true when grown near each other. I should have expected that they would have been crossed by the bees bringing pollen from other varieties; and I should be infinitely obliged for any information on this head from any of your correspondents. As I have mentioned bees, a little fact which surprised me may be worth giving:—One day I saw for the first time several large humble-bees visiting my rows of the tall scarlet Kidney Bean; they were not sucking

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at the mouth of the flower, but cutting holes through the calyx, and thus extracting the nectar. I watched this with some attention, for though it is a common thing in many kinds of flowers to see humble-bees sucking through a hole already made, I have not very often seen them in the act of cutting. As these humble-bees had to cut a hole in almost every flower, it was clear that this was the first day on which they had visited my Kidney Beans. I had previously watched every day for some weeks, and often several times daily, the hive-bees, and had seen them always sucking at the mouth of the flower. And here comes the curious point: the very next day after the humble-bees had cut the holes, every single hive bee, without exception, instead of alighting on the left wing-petal, flew straight to the calyx and sucked through the cut hole; and so they continued to do for many following days. Now how did the hive-bees find out that the holes had been made? Instinct seems to be here out of the question, as the Kidney Bean is an exotic. The holes could scarcely be seen from any point, and not at all from the mouth of the flower, where the hive-bees hitherto had invariably alighted. I doubt whether they were guided by a stronger odour of the nectar escaping through the cut holes; for I have found in the case of the little blue Lobelia, which is a prime favourite of the hive-bee, that cutting off the lower striped petals deceived them; they seem to think the mutilated flowers are withered, and they pass them over unnoticed. Hence I am strongly inclined to believe that the hive-bees saw the humble-bees at work, and well understanding what they were at, rationally took immediate advantage of the shorter path thus made to the nectar.3 C. Darwin, Down, Bromley, Kent, Oct.18.

1 2 3

George Swayne (1746–1827), botanist and clergyman. Swayne 1824. Two-flowered Everlasting-pea. See Natural selection, pp. 475–6 and CCD6: 465–7.

1857. Productiveness of foreign seed. Gardeners’ Chronicle and Agricultural Gazette no. 46 (14 November): 779. F1698 Will the writer of the highly remarkable article on weeds in your last Number have the kindness to state why he supposes that “there is too much reason to believe that foreign seed of an indigenous species is often more prolific than that grown at home?”1 Is it meant that the plant produced from the foreign seed actually produces more seed, or merely that the introduced stock is more vigorous than the native stock? I have no doubt that so acute an observer has some good reason for his belief. The point seems to me of considerable interest in regard to the great battle for life which is perpetually going on all around us. The great American botanist, Dr. Asa Gray,2 believes that in the United States there are several plants now naturalised in abundance from imported seed, which are likewise indigenous; and my impression is (but writing from home I cannot refer to his letter to me) that the imported stock prevails over the aboriginal. So again, Dr. Hooker in his admirable Flora of New Zealand3 has told us that the common Sonchus4 has spread extensively from imported seed, whilst the same species is likewise an aboriginal; the natives in this instance being able from trifling differences to distinguish the two stocks. Might I further ask whether it is now some years since the seed of Sinapis nigra was accidentally introduced on the farm described; and

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if so, whether the common Charlock still remains in lessened numbers owing to the presence of the invader, and without, as far as known, fresh seed of the invading S. nigra having been introduced?—whether, in short, it was a fair fight between the two species, ending in the victory of the Black Mustard? Would it be trespassing too much on the kindness of the writer of the article to ask whether he knows of any other analogous cases of a weed introduced from other land beating out, to a greater or lesser extent, a weed previously common in any particular field or farm? C. Darwin, Down, Bromley, Kent.

1

2

3 4

The quoted passage reads: ‘The manner in which weeds are spread over some farms may be observed in the increase of exotic species from the use of foreign seeds, a circumstance which accounts for the increase of plants in our English Flora within the last few years. However these, as being wholly foreigners, seldom make rapid progress, whilst there is too much reason to believe that foreign seed of an indigenous species is often more prolific than that grown at home.’ anon 1857. See CCD6: 482–4. Asa Gray (1810–88), American botanist, Fisher Professor of natural history, Harvard University, 1842–88, and close friend of CD’s. CD refers to the 16 February 1857 letter from Gray, see CCD6: 339–42. Hooker 1853–55. Sow thistle.

1858. [Letter on zoological nomenclature]. In Jardine W. ed., Memoirs of Hugh Edwin Strickland, M.A. London: John Van Voorst, p. clxxv. F1983 I have read carefully your laws and suggestions, and have been able to make only one or two unimportant notes. As far as my judgment goes, the laws appear very well digested and clearly written.1

1

CD refers to a printed draft of a committee report to the British Association for the Advancement of Science ‘to consider of the rules by which the Nomenclature of Zoology may be established on a uniform and permanent basis’ which was published as Darwin et al. 1842, F1661a. The complete letter, dated 17 February [1842], along with detailed notes, is published in CCD2: 311.

1858. Memorial of the promoters and cultivators of science on the subject of the proposed severance from the British Museum of its natural history collections, addressed to Her Majesty’s Government. House of Commons Papers; Accounts and Papers (XXXIII.499) 456 (23 July): 1–5. F1942 British Museum Return to an Address of the Honourable The House of Commons, dated 6 July 1858;—for, A “Copy of a Memorial addressed to Her Majesty’s Government by the Promoters and Cultivators of Science on the Subject of the proposed Severance from the British Museum of its Natural History Collections, together with the Signatures attached thereto.” Treasury Chambers 19 July 1858. Geo. A. Hamilton.

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(Sir Philip Grey Egerton.) Ordered, by The House of Commons, to be Printed, 23 July 1858. 456. |2| Memorial of the Promoters and Cultivators of Science on the Subject of the proposed Severance from the British Museum of its Natural History Collections, addressed to Her Majesty’s Government.1 The Report of the Royal Commission appointed to inquire into the best site for a National Gallery, and recent discussions in Parliament having led to the contemplation of breaking up the British Museum, by severing from it the Natural History Collections, we, the undersigned, promoters and cultivators of natural knowledge, beg to record our strong objections to such removal, and for the following reasons:— 1st. The British Museum, when established by Act of Parliament in 1755, was essentially a Natural History Collection, the enlightened views of its founder, Sir Hans Sloane,2 being that it should “be rendered as useful as possible, as well towards satisfying the desire of the curious as for the improvement, knowledge and information of all persons.” 2d. This object of Sir Hans Sloane has been so satisfactorily carried out, that according to the Report of the last Royal Commission, which inquired into the whole state of the Museum (1849), “the evidence of men of the highest authority in science was referred to with great satisfaction, to show that the Natural History Collections were, as a whole, equal if not superior to any in the world.” 3d. Whilst we are aware that much greater space is required to provide for the reception of antiquities and ancient sculpture (chiefly on the ground floor) it has been ascertained by the Trustees,3 that when additional buildings shall be called for, they can be extended northwards in halls requiring little embellishment, and, according to a plan laid before the Trustees by Mr. Smirke,4 involving a considerably less expenditure than that which must, be incurred by a transference of those collections to any other spot, and the consequent erection of an entirely new edifice. On this point we beg to quote the follow-[ing] resolutions adopted by the Trustees of the British Museum, composing the Standing Committee, as printed in a Return to the House of Commons, dated 4th February 1858. “The Committee having had under their consideration the report of the principal librarian,5 dated 10th November 1857, “Resolved,— 1. That it appears from such report that there is a great, deficiency of space at present for the proper exhibition of the different collections in the different departments of the Museum, and that there is no vacant space now belonging to the Trustees which will be sufficient to provide for such deficiency. 2. That in providing an adequate space for that purpose, it is very desirable to contemplate the future and progressive, as well as the actual and immediate requirements of the British Museum. 3. That it appears to the Trustees that the best mode of providing for such present and future requirements will be by adopting the plan submitted by Mr. Smirke for the

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purchase of land to the north of the Museum, as contained in the report of the principal librarian. 4. That, in the opinion of the Trustees, even if the increase of the collections which are under their care should at some future time make it |3| necessary to transfer any of those collections to some other place, the land of which the purchase is now recommended must always be of great and peculiar value to the Museum. 5. That such plan, together with the present resolutions, shall be laid before Her Majesty’s Ministers with the view of requesting their concurrence therein, and their recommendation thereof to the consideration of Parliament.” 4th. Presuming that few persons will be found to advocate the removal of the grand masses of ancient art from their present position, so it is manifest that, if all the Natural History Collections be taken away their transference will afford no place for the classical works, which now temporarily encumber the principal facade, or crowd the crypts below. For, as such massive objects must be placed on the ground floor, so an extension of the basement is inevitable, if the antiquities remain part of the Museum, and all that the Natural History Collections can require for their future development will be an allotment of space above such extension of the ground floor. We would also observe that the prolongation of the present building northwards on the above-mentioned plan, besides being much less costly than the formation of an entirely new building, will put a stop to all controversies respecting the appropriate site, and the style of architecture to be applied to a new building. 5th. In reference to other suggestions that have been vaguely thrown out, of a breaking up of the Natural History Collections of the nation into several parts, by transferring, e.g. the minerals to the Government School of Mines; the stuffed animals to the Zoological Society; the insects and shells to the Linnean Society, &c., we have first to observe, that not any of the above institutions, two of which are only voluntary associations of individuals, possesses the space or means for the reception and display of such constituent parts of the great national series of illustrations of nature; and, further, that as the chief end and aim of natural history is to demonstrate the harmony which pervades the whole, and the unity of principle which bespeaks the unity of the Creative Cause, it is essential that the different classes of natural objects should be preserved in juxtaposition under the roof of one great building. 6th. We further strongly object to the proposed transference, because those engaged in the study of natural history have in the British Museum the paramount advantage of consulting every work which can aid their researches; whilst a removal of the collections would either involve a conjoint transference of a very large portion of the National Library, or necessitate a very expensive purchase of a special Natural History Library. 7th. Whilst such are among the prominent reasons against the removal of the Natural History Collections from the site where they have been established, for upwards of a century, in the centre of London, we beg to add the expression of our opinion that such removal, particularly if to any situation distant from that centre; would be viewed by

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the mass of the inhabitants with extreme disfavour; it being a well-known fact that by far the greater number of visitors to the Museum consists of those who frequent the halls containing the Natural History Collections; whilst, it is obvious that many of those persons who come from the densely peopled districts of the eastern, northern, and southern parts of London would feel it very inconvenient to resort to any distant locality. For these reasons, as based on scientific advantages, the convenience and instruction of the people, and the saving of a large sum to the nation, we earnestly hope that the Natural History Collections may not be interfered with, but be allowed to remain associated with the many other branches of human knowledge which are so admirably represented in this great national establishment. |4| Her Majesty’s Government, we trust, will never yield to the argument that, because in some countries the products of Nature and Art are exhibited in distinct establishments, therefore the like separation should be copied here. Let us, on the contrary, rejoice in the fact, that we have realised what no other kingdom can boast of, and that such vast and harmoniously related accumulation of knowledge is gathered together around a library, illustrating each department of this noble Museum. Charles Darwin, F. R. S., &c. [The other 113 names are omitted.]

1

2 3 4 5

CD signed two memorials or petitions that were presented to government in 1858 on the subject of the proposed move of the British Museum’s natural history collections to a new site. See CCD7, appendix VI where the memorials are reproduced together with a useful introduction. See Darwin 1858, F1702 (p. 278). Hans Sloane (1660–1753), physician and collector who bequeathed his collections to the nation in 1753, leading to the foundation of the British Museum in 1754. There were 49 trustees of the British Museum. See CCD7: 529 note 1. Robert Smirke (1781–1867), London architect who designed the British Museum and several other London buildings. Anthony Panizzi (1797–1879), Italian-born librarian exiled in Britain. He was assistant librarian of the British Museum, 1831 and principal librarian, 1856–66.

1858. On the agency of bees in the fertilisation of papilionaceous flowers, and on the crossing of kidney beans. Gardeners’ Chronicle and Agricultural Gazette no. 46 (13 November): 828–9. F17011 Last year you published a brief notice by me on this subject.2 I therein stated that bees always alight on the left wing-petal of the Scarlet Kidney Bean, and in doing so depress it; and this acts on the tubular and spiral keel-petal, which causes the pistil to protrude; on the pistil there is a brush of hairs, and by the repeated movement of the keel-petal the hairs brush the pollen beyond the anthers on to the stigmatic surface. This complex contrivance led me to suppose that bees were necessary to the fertilisation of the flower; accordingly I enclosed some few flowers in bottles and under gauze, and those which were not in any way moved

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did not set a single pod, whereas some of those which I moved in imitation of the bees produced fine pods. But I then stated that the experiment was tried on much too small a scale to be trusted. I have this year covered up between 3 and 4 feet in length of a row of Kidney Beans, just before the flowers opened, in a tall bag of very thin net; nothing in the appearance of the plants would lead me to suppose that this was in any way injurious to their fertilisation; and I think this conclusion may be trusted, for some of the flowers which I moved in the same way as the bees do produced pods quite as fine as could be found in the uncovered rows. The result was that the covered up plants had produced by August 13th only 35 pods, and in no one case two pods on the same stalk; whereas the adjoining uncovered rows were crowded with clusters of pods. There were many flowers still on the plants when uncovered, and it was curious to see in a few days afterwards, as soon as the bees had access to them, what a number of pods hanging in clusters of three and four together were produced. On August 17th I again put the net on a later crop. The covered plants now produced 97 pods, borne on 74 stalks, showing that the same stalk often produced more than one pod. This time I kept an equal length of uncovered Beans ungathered, and on this length there were 292 pods or exactly thrice as many as on the covered plants. Taking this number as the standard of comparison for the first experiment (which, however, is hardly fair, as my gardener thinks the second crop was more productive than the first) more than eight times as many pods were produced on the uncovered as on the covered rows. The Kidney Bean is largely frequented by the thrips,3 and as I have with some other plants actually seen a thrips which was dusted with pollen leave several granules on the stigma, it is quite possible that the fertilisation of the covered-up flowers might have been thus aided. In the common Bean there is no such obvious relation between the structure of the flower and the visits of bees; yet when these insects alight on the wing-petals they cause the rectangularly bent pistil and the pollen to protrude through the slit in the keel-petal. I was led to try the effect of covering them up, from a statement in the Gardeners’ Chronicle made several years ago,4 viz., that when bees bite holes through the calyx of the flower in order to get more easily at the nectar, the crop is injured. This was attributed by the writer to injury of the ovarium, which I am sure is incorrect. But I thought that it was possible that the fertilisation would be less perfect, as soon as bees ceased to alight on the wing-petals. I accordingly covered up 17 plants, just before the flowers opened, moving a few flowers to ascertain that very fine pods, including the full average number of Beans, could be, and were, produced on the plants under the net. These 17 plants produced 36 pods; but no less than eight of them, though well formed, did not include a single Bean. The 36 pods together contained only 40 Beans, and, if the empty pods be excluded, each produced on an average less than one and a half Beans; on the other hand 17 uncovered plants in an adjoining row which were visited by the bees produced 45 pods, all including Beans, 135 in number, or on an average exactly three Beans to each pod. So that the uncovered Beans were nearly thrice as fertile as the covered.

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In an old number of the Gardeners’ Chronicle5 an extract is given from a New Zealand newspaper in which much surprise is expressed that the introduced Clover never seeded freely until the hive-bee was introduced. This statement may be erroneous; at least, as I shall immediately show, it does not apply to the Canterbury settlement. But I was induced by it to cover up under the same open sort of net about a yard square of the common White Clover, growing thickly in turf; and then gathered an equal number of heads from the covered and from some uncovered plants which were growing all round, and which I had seen daily visited by my bees. I collected the seed into a small parcel, and as far as I could estimate, the uncovered plants produced just ten times as much seed as the covered. Speaking loosely, the covered heads might have been said to have produced no seed. Lathyrus grandiflorus is very rarely visited by bees in this country; and from experiments which I have tried during the two last summers, and from experiments recorded in Loudon’s Magazine,6 I am convinced that moving the flowers favours their fertilisation, even when the young pod falls off, as very often happens almost immediately. Sir W. Macarthur,7 who did not know of my experiments, told me that he had found that in New South Wales the introduced Erythrina8 did not set its pods well without the flowers were moved. From the statement in regard to the Clover in New Zealand, I wrote to Mr. Swale,9 of Christchurch in New Zealand, and asked him whether Leguminous plants seeded there freely before the hive bee was introduced; and he in the most obliging manner has sent me a list of 24 plants of this order, which seeded abundantly before bees were introduced. And as he states that there is no indigenous bee (perhaps this statement applies to bees resembling hive or humble bees, for some other genera are known to inhabit New Zealand), the fact that these plants seeded freely at first appears quite fatal to my doctrine. But Mr. Swale adds that he believes that three species of a wasp-like insect performed the part of bees, before the introduction of the latter; unfortunately he does not expressly state that he has seen them sucking the flower. He further adds a remarkable statement, that there are two or three kinds of grasshoppers which frequent flowers, and he says he has repeatedly watched them “release the stamens from the keel-petal.” So that, extraordinary as the fact is, it would appear that grasshoppers, though having a mouth so differently constructed, in New Zealand have to a certain extent the habits of bees. Mr. Swale further adds, that the garden varieties of the Lupine seed less freely than any other Leguminous plant in New Zealand, and he says, “I have for amusement during the summer released the stamens with a |829| pin, and a pod of seed has always rewarded me for my trouble, and the adjoining flowers not so served have all proved blind.”10 The case of the Lupine in New Zealand not seeding freely now that bees have been introduced, may be accounted for by the fact, if I dare trust my memory, that in England this plant is visited by humble bees and not by hive bees. These several facts, and the foregoing experiments, seem to me rather curious; for who, seeing that papilionaceous11 flowers are hermaphrodite, have an abundant supply of pollen, which is mature before the flower opens, and that the flower itself is so neatly closed, would have imagined that insects played so important a part in their fertilisation? I can hardly doubt that in England, during a season when bees were very scanty, if in any one district large crops

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of seed-Clover were planted, the crop would partly fail from the flowers not being sufficiently moved. The foregoing little experiments, however, were not tried in relation to the agency of insects in fertilising a plant with its own pollen. Andrew Knight12 many years ago propounded the doctrine that no plant self-fertilises itself for a perpetuity of generations. After pretty close investigation of the subject, I am strongly inclined to believe that this is a law of nature throughout the vegetable and animal kingdoms. I am well aware that there are several cases of difficulty. The Leguminosæ with papilionaceous flowers have been advanced by Pallas13 and others as a case in which crossing could never naturally take place. But any plant habitually visited by insects in such a manner that their hairy bodies, to which pollen so readily adheres, come into contact with the stigma, could hardly fail occasionally to receive the pollen from another individual of the same species. In all Leguminosæ bees do brush over the stigma. And the possibility of crossing would be very strong in the case of any plant, if the agency of insects were necessary for its self-fertilisation; [= self-pollination] for it would show that it was habitually visited by them. From these considerations I was led to believe that papilionaceous plants must be occasionally crossed. Nevertheless I must confess that from such evidence as I have been able to acquire, crossing between varieties growing close together does not take place nearly so freely as I should have expected. As far as I am aware only three or four cases of such crosses are on record. It is not by any means, I believe, a common practice with seed raisers to keep the crops of their Leguminous plants separate. Hence I was led last year in my short communication to the Gardeners’ Chronicle14 to ask whether any of your readers had any experience on the natural crossing of Beans, Peas, &c. Mr. Coe,15 of Knowle, near Fareham, Hants, in the most obliging manner sent me some specimens, and an account that last summer he had planted four rows of the Negro Dwarf Kidney Bean, between some rows of the white and brown dwarfs, and likewise near some Scarlet Runners. The dwarfs he had saved for seed. The plants themselves he believes presented nothing remarkable in foliage, height, flowers, &c.; and he feels sure that their pods were all alike; but the Beans themselves presented an extraordinary mixture, as I can testify from the sample sent me, of all shades between light brown and black, and a few mottled with white; not one-fifth of the Beans, perhaps much less, were pure Negroes. Some few of the Beans also in the rows of the white Haricot were affected, but none of the brown dwarfs. Hence, then, we apparently have the extraordinary fact described by Wiegmann16 in the case of several Leguminous plants, experimentised on most carefully by Gärtner in the case of the Pea, and described a few years ago by Mr. Berkeley in the Gardeners’ Chronicle,17 of the pollen of one variety having affected not only the embryo but the tunics of the seed borne by the pure mother. I have said that apparently we have here a fact of this nature; for I must state that Mr. Coe sent me a dozen of the pure Negro Beans which produced in 1857 the extraordinary mixture. I sowed them this year, and though quite like each other, the dozen produced plants differing in colour of flower, &c., and Beans of various tints; so that these Beans, though not affected in their outer tunics, seem to have been the product of a cross in the previous year of 1856.

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This year I sowed the extraordinary mixture raised by Mr. Coe in 1857 from the four rows of the Negro Bean, which he believes to have been quite pure; and the produce is the most extraordinarily heterogeneous mixture which can be conceived; each plant differing from the others in tallness, foliage, colour, and size of flower, time of ripening and flowering, size, shape, and colour of pods, and Beans of every conceivable tint from black to pale brown, some dark purple and some slightly mottled, and of various sizes and shapes. My gardener18 remarked, as did Mr. Coe with respect to some of his plants, that some of the seedlings seemed to have been crossed by the Scarlet Runner; one of my plants trailed on the ground for a length of 4 feet, its flowers were white and its pods were very long, flat, and broad; the Beans were pinkish purple, and twice as large as those of the Negro; there were also in two cases brown and purple Beans in the same pod. These facts certainly seem to indicate a cross from the Scarlet Runner; but as the latter is generally esteemed a distinct species, I feel very doubtful on this head; and we should remember that it is well established that Mongrels frequently, or even generally, are much more vigorous than either of their parents. Mr. Coe tried the experiment more philosophically, and separated his heterogeneous Negro Beans into 12 lots, according to their tints, and keeping a few of each as a sample, he sowed them and he has now harvested them separately. He has kindly sent me samples of all. The variation is now much greater than it was in the parent lot of 1857. Beans of new colours have appeared, such as pure white, bright purple, yellow, and many are much mottled. Not one of the 12 lots has transmitted its own tint to all the Beans produced by it; nevertheless, the dark Beans have clearly produced a greater number of dark, and the light coloured Beans a greater number of light colour. The mottling seems to have been strongly inherited, but always increased. To give one case of the greatest variability, a dirty brown Bean, nearly intermediate in tint between the darkest and lightest, produced a sample, which I have been enabled to divide into no less than a dozen different tints, viz., pure white, black, purple, yellow, and eight other tints between brown, slate, yellow, purple, or black. It has been stated that a few of the white Haricots in the rows adjoining the Negroes were in 1857 slightly affected; Mr. Coe sowed some which were of a very pale brown or cream-coloured; and he has sent me a pod produced this autumn, which pod includes two Beans of the above tint and one of a pale dirty purplish-brown. Now it may be asked are we justified in attributing this extraordinary amount of variation to crossing, whether or not the crossing was all confined to the year 1857; or may not the case be one of simple variation? I think we must reject the latter alternative. For in the first place the Negro Bean is an old variety and is reputed to be very true; in the second place, I do not believe any case is on record of a vast number of plants of the same variety all sporting at the very same period. On the other hand, the Negroes having been planted between rows of white and brown Beans, together with the facts which I have given on the importance of insect agency in the fertilisation of the Kidney Bean, showing, as may be daily seen, how incessantly the flowers are visited by bees, strongly favours the theory of crossing. Moreover the extraordinary increase in variability in the second generation strikingly confirms this conclusion, for extreme variability in the offspring from mongrels has been observed by all who have attended to this subject.

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As seed-raisers do not usually take any precautions in separating their crops of Leguminous plants, it may be asked, how are we to account for the extraordinary amount of crossing in Mr. Coe’s plants in 1857, when almost every plant in the four rows of the Negro seems to have been affected? I may here add that in an old paper in the Journal of the Bath Agricultural Society19 there is an almost exactly parallel account of the crossing of several varieties of the common Bean throughout a whole field. Insect agency is always at work; but the movement of the corolla will generally tend merely to push the flower’s own pollen, which is mature as soon as the flower is open, on to the stigmatic surface; and even if pollen is brought by the bees from another flower, the chances are in favour of pollen from the same variety being brought, where a large stock is cultivated. I can explain Mr. Coe’s case, and that in the Bath Journal, only on one hypothesis, viz., that from some cause the Negro Beans did not at Knowle, in 1857, produce good pollen, or they matured it later than usual. This has been shown by Gärtner sometimes to occur, and would explain with the aid of insect agency the whole case. Believing, as I do, that it is a law of nature that every organic being should occasionally be crossed with a distinct individual of the same species, and seeing that the structure of papilionaceous flowers causes the plant’s own pollen to be pushed on to its own stigma, I am inclined to speculate a little further. It is, I think, well ascertained that very close interbreeding tends to produce sterility, at least amongst animals. Moreover, in plants it has been ascertained that the male organs fail in fertility more readily than the female organs, both from hybridity and from other causes, and further that they resume their fertility slower, when a hybrid is crossed in successive generations with either pure parent, than do the female organs. May we not then suppose in the case of Leguminous plants, after a long course of self-fertilisation, that the pollen begins to fail, and then, and not till then, the plants are eagerly ready to receive pollen from some other variety? Can this be connected with the apparently short duration and constant succession of new varieties amongst our Peas, and as is stated to be the case on the Continent with Kidney Beans? These speculations may be valueless, but I venture earnestly to request any of your correspondents who may have noticed any analogous facts on sudden and large variation in their seed-crops of any Leguminous plants (including Sweet Peas), or any facts on such plants having kept true for many consecutive generations, when grown near each other, to have the kindness to take the trouble to communicate them to the Gardeners’ Chronicle,20 or to the following address. C. Darwin, Downe, Bromley, Kent.

1

2 3 4 5 6

Reprinted in Annals and Magazine of Natural History (Ser. 3) 2: 459–65. See the response to CD’s inquiry in J. B. W. 1858. CCD7: 196 suggests the ‘initials may stand for John Bland Wood, a noted collector and botanist from Manchester’. Darwin 1857, F1697 (p. 267). Tiny, slender insects with fringed wings. Ruricola 1841. R. 1843. John Claudius Loudon’s Gardener’s Magazine, J. D. 1832, p. 50.

278 7 8 9 10 11 12 13 14 15 16 17 18 19

20

1858. [Memorial] Public natural history collections

William Macarthur (1800–82), Australian horticulturist and amateur botanist. See CCD7: 189–96. A genus of tropical and subtropical flowering trees in the Family Fabaceae common in tropical and subtropical regions. William Swale (1816–75), Norfolk-born gardener who emigrated to Christchurch, New Zealand, and became a well-known nurseryman. See letter from W. Swale, 13 July 1858, CCD7: 134–6. Flowers with a bilaterally symmetrical corolla somewhat resembling a butterfly, characteristic of most plants of the pea family. Thomas Andrew Knight (1759–1838), botanist and distinguished plant hybridizer. Knight 1799. See also Natural selection, p. 42 note 1. Peter Simon Pallas (1741–1811), German naturalist and geographer. Darwin 1857, F1697 (p. 267). See CCD7: 196. Henry Coe, gardener to the lunatic asylum at Fareham, Hampshire. See CCD7. Arend Friedrich Wiegmann (1771–1853), German pharmacist and botanist. Wiegmann 1828. Berkeley 1854. See CCD5. Henry Lettington (b. 1822/3), CD’s gardener, 1854–79. This reference has not been traced. CCD7: 196 suggests: ‘He presumably refers to Letters and Papers of the Bath and West of England Society for the Encouragement of Agriculture, Arts, Manufactures, and Commerce, which was published, with some interruption, between 1780 and 1829.’ See CCD7: 196 note 21.

1858. [Memorial] Public natural history collections. Gardeners’ Chronicle and Agricultural Gazette no. 48 (27 November): 861. F1702 To the Right Honourable the Chancellor of the Exchequer.1 Sir,—The necessity of the removal of the Natural History Departments from the British Museum having been recently brought prominently before the Public, and it being understood that the question of their reorganisation in another locality is under consideration, the undersigned Zoologists and Botanists, professionally or otherwise engaged in the pursuit of Natural Science, feel it their duty to lay before Her Majesty’s Government the views they entertain as to the arrangements by which National Collections in Natural History can be best adapted to the twofold object of the advancement of Science, and its general diffusion among the Public—to show how far the Scientific Museums of the Metropolis and its vicinity, in their present condition, answer these purposes,—and to suggest such modifications or additional arrangements as appear requisite to render them more thoroughly efficient. The Scientific Collections or Museums, whether Zoological or Botanical, required for the objects above stated, may be arranged under the following heads:— 1. A general and comprehensive Typical or Popular Museum, in which all prominant forms or types of Animals and Plants, recent or fossil, should be so displayed as to give the Public an idea of the vast extent and variety of natural objects, to diffuse a general knowledge of the results obtained by Science in their investigation and classification, and to serve as a general introduction to the Student of Natural History. 2. A complete Scientific Museum, in which Collections of all obtainable Animals and Plants, and their parts, whether recent or fossil, and of a sufficient number of specimens,

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should be disposed conveniently for study; and to which should be exclusively attached an appropriate Library, or Collection of Books and Illustrations relating to Science, wholly independent of any general Library. 3. A comprehensive Economic Museum, in which Economic Products, whether Zoological or Botanical, with Illustrations of the processes by which they are obtained and applied to use, should be so disposed as best to assist the progress of Commerce and the Arts. 4. Collections of Living Animals and Plants, or Zoological and Botanical Gardens. The Typical or Popular Museum, for the daily use of the general Public, which might be advantageously annexed to the Scientific Museum, would require a large building, in a light, airy, and accessible situation. The Collections should be displayed in spacious galleries, in glass cases, so closed as to protect them from the dirt and dust raised by the thousands who would visit them; and sufficient room should be allowed within the cases to admit of affixing to the specimens, without confusion, their names, and such illustrations as are necessary to render them intelligible and instructive to the Student and the general Public. The Economic Museums and Living Collections in Botany might be quite independent of the Zoological ones. The Scientific Museum, in Zoology as in Botany, is the most important of all. It is indispensable for the study of Natural Science, although not suited for public exhibition. Without it, the Naturalist cannot even name or arrange the materials for the Typical, Economic, or Living Collections, so as to convey any useful information to the Public. The specimens, though in need of the same conditions of light, airiness, &c., as, and far more numerous than, those exposed in the Typical or Popular Museum, would occupy less space; and they would require a different arrangement, in order that the specimens might, without injury, be frequently taken from their receptacles for examination. This Scientific Museum, moreover, would be useless unless an appropriate Library were included in the same building. The union of the Zoological and Botanical Scientific Museums in one locality is of no importance. The juxtaposition of each with its corresponding Living Collection is desirable, but not necessary—although, in the case of Botany, an extensive Herbarium and Library are indispensable appendages to the Garden and Economic Museum. The existing Natural History Collections accessible to Men of Science and to the Public, in or near the Metropolis, are the following:— In Botany.—The Kew Herbarium, as a Scientific Collection, is the finest in the world; and its importance is universally acknowledged by Botanists. It has an excellent Scientific Library attached to it; it is admirably situated; and being in proximity with, and under the immediate control of the Head of the Botanic Garden, it supersedes the necessity of a separate Herbarium for the use of that Garden and Museum. But a great part of it is not the property of the State; there is no building permanently appropriated for its accommodation, and it does not include any Collection of Fossil Plants. The Botanical Collection of the British Museum, consisting chiefly of the Banksian Herbarium, is important, but very imperfect. It is badly situated, on account of the dust

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and dirt of Great Russell Street; and the want of space in the existing buildings of the British Museum would prevent its extension, even were there an adequate advantage in maintaining, at the cost of the State, two Herbaria or Scientific Botanic Museums so near together as those of London and Kew. The British Museum also contains a valuable Collection of Fossil Plants, but not more readily available for Science than its Zoological Collections. There exists no Typical or Popular Botanical Museum for public inspection. The efficiency of the Botanical Gardens and Museum of Economic Botany at Kew, as now organised, and the consequent advantages to Science and the Public, are too generally recognised to need any comment on the part of your Memorialists. In Zoology.—The British Museum contains a magnificent Collection of Recent and Fossil Animals, the property of the State, and intended both for public exhibition and for scientific use. But there is no room for its proper display, nor for the provision of the necessary accommodation for its study—still less for the separation of a Popular Typical series for public inspection, apart from the great mass of specimens whose importance is appreciated only by professed Naturalists. And, in the attempt to combine the two, the Public are only dazzled and confused by the multiplicity of unexplained objects, densely crowded together on the shelves and cases; the man of science is, for three days in the week, deprived of the opportunity of real study; and the specimens themselves suffer severely from the dust and dirt of the locality, increased manifold by the tread of the crowds who pass through the galleries on Public Days,—the necessity of access to the specimens on other days preventing their being arranged in hermetically closed cases. A Museum of Economic Zoology has been commenced at South Kensington. There is an unrivalled Zoological Garden or Living Collection, well situated in the Regent’s Park, but not the property of the State, nor receiving any other than indirect assistance, in the terms on which its site is granted. The measures which your Memorialists would respectfully urge upon the consideration of her Majesty’s Government, with a view to rendering the Collections really available for the purposes for which they are intended, are the following:— That the Zoological Collections at present existing in the British Museum be separated into two distinct Collections,—the one to form a Typical or Popular Museum, the other to constitute the basis of a complete Scientific Museum. These Museums might be lodged in one and the same building, and be under one direction, provided they were arranged in such a manner as to be separately accessible; so that the one would always be open to the Public, the other to the man of science, or any person seeking for special information. This arrangement would involve no more trouble, and would be as little expensive as any other which could answer its double purpose, as the Typical or Popular Museum might at once be made almost complete, and would require but very slight, if any, additions. In fact, the plan proposed is only a further development of the system according to which the Entomological, Conchological, and Osteological Collections in the British Museum are already worked.

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That an appropriate Zoological Library be attached to the Scientific Museum, totally independent of the Zoological portion of the Library of the British Museum, which, in the opinion of your Memorialists, is inseparable from the General Library. That the Scientific Zoological Museum and Library be placed under one head, directly responsible to one of her Majesty’s Ministers, or under an organisation similar to that which is practically found so efficient in regard to Botany. That the Museum of Economic Zoology at South Kensington be further developed. Your Memorialists recommend that the whole of the Kew Herbarium become the property of, and be maintained by, the State, as is now the case with a portion of it—that the Banksian Herbarium and the Fossil Plants be transferred to it from the British Museum—and that a permanent building be provided for the accommodation at Kew of the Scientific Museum of Botany so formed. This consolidation of the Herbaria of Kew with those of the British Museum would afford the means of including in the Botanical Scientific Museum a Geographical Botanical Collection for the illustration of the Colonial Vegetation of the British Empire, which, considering the extreme importance of vegetable products to the commerce of this country, your Memorialists are convinced would be felt to be a great advantage. Your Memorialists recommend further, that in place of the Banksian Herbarium and other miscellaneous Botanical Collections now in the British Museum and closed to the Public, a Typical or Popular Museum of Botany be formed in the same building as that proposed for the Typical or Popular Museum of Zoology, and, like it, be open daily to the Public. Such a Collection would require no great space; it would be inexpensive, besides being in the highest degree instructive; and, like the Typical or Popular Zoological Collection, it would be of the greatest value to the public, and to the Teachers and Students of the Metropolitan Colleges. That the Botanical Scientific Museum and its Library, the Museum of Economic Botany, and the Botanic Garden, remain, as at present, under one head, directly responsible to one of her Majesty’s Ministers. The undersigned Memorialists, consisting wholly of Zoologists and Botanists, have offered no suggestions respecting the very valuable Mineralogical Collection in the British Museum, although aware that, in case it should be resolved that the Natural History Collections generally should be removed to another locality, the disposal of the Minerals also will probably come under consideration. November 18, 1858. Chas. Darwin, F. R. S., L. S., and G. S. [The other 8 names are omitted.]

1

This memorial was also published by John Lindley in the Athenaeum, 27 November 1858, pp. 684–5 and by botanist George Bentham (1800–84) in Nature (9 June 1870): 97–8. CD signed two memorials or petitions that were presented to government in 1858 on the subject of the proposed move of the British Museum’s natural history collections to a new site. See Darwin 1858, F1942

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(p. 269) and CCD7, appendix VI where the memorials are reproduced together with a useful introduction. Benjamin Disraeli (1804–81), Chancellor of the Exchequer in 1858.

1858. [Contribution to the Field-Lane refuges]. The Times (29 December): 10. F1935 Sir,—The tide of interest excited by your invaluable articles on the 24th seems this day to have risen rather than to have abated; and I must again throw myself upon your kind indulgence to respond to the request of our numerous kind donors for an acknowledgement of their kindness in The Times—a speaking tribute to your resistless appeal. I am, Sir, yours ever most gratefully and respectfully, Samuel Tawell, Hon. Sec. 20, Aldermanbury, Dec. 28. […] Contributions received by Secretary, requested to be acknowledged in The Times:— […] Mr. C. Darwin, 3l. [The lengthy list of co-contributors is omitted.]1

1

The Field Lane Refuge, at the north side of Vine Street in Clerkenwell, London, was a charitable housing and Christian mission centre for the poor and unemployed. Samuel Tawell was a lace manufacturer.

Darwin C. R. and A. R. Wallace. 1858. On the tendency of species to form varieties; and on the perpetuation of varieties and species by natural means of selection. By Charles Darwin, Esq., F. R. S., F. L. S., & F. G. S., and Alfred Wallace, Esq. Communicated by Sir Charles Lyell, F. R. S., F. L. S., and J. D. Hooker, Esq., M.D., V. P. R. S., F. L. S, &c. [Read 1 July] Journal of the Proceedings of the Linnean Society of London. Zoology 3 (20 August): 46–50. F3501 London, June 30th, 1858. My Dear Sir,—The accompanying papers, which we have the honour of communicating to the Linnean Society, and which all relate to the same subject, viz. the Laws which affect the Production of Varieties, Races, and Species, contain the results of the investigations of two indefatigable naturalists, Mr. Charles Darwin and Mr. Alfred Wallace. These gentlemen having, independently and unknown to one another, conceived the same very ingenious theory to account for the appearance and perpetuation of varieties and of specific forms on our planet, may both fairly claim the merit of being original thinkers in this important line of inquiry; but neither of them having published his views, though Mr. Darwin has for many years past been repeatedly urged by us to do so, and both authors having now unreservedly placed their papers in our hands, we think it would best promote the interests of science that a selection from them should be laid before the Linnean Society.

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Taken in the order of their dates, they consist of:— 1. Extracts from a MS. work on Species,* by Mr. Darwin, which was sketched in 1839, and copied in 1844,2 when the copy was read by Dr. Hooker,3 and its contents afterwards communicated to Sir Charles Lyell. The first Part is devoted to “The Variation of Organic Beings under Domestication and in their Natural State;” and the second chapter of that Part, from which we propose to read to the Society the extracts referred to, is headed, “On the Variation of Organic Beings in a state of Nature; on the Natural Means of Selection; on the Comparison of Domestic Races and true Species.” 2. An abstract of a private letter addressed to Professor Asa Gray, of Boston, U.S., in October4 1857, by Mr. Darwin, in which |46| he repeats his views, and which shows that these remained unaltered from 1839 to 1857.5 3. An Essay by Mr. Wallace, entitled “On the Tendency of Varieties to depart indefinitely from the Original Type.”6 This was written at Ternate in February 1858, for the perusal of his friend and correspondent Mr. Darwin, and sent to him with the expressed wish that it should be forwarded to Sir Charles Lyell, if Mr. Darwin thought it sufficiently novel and interesting. So highly did Mr. Darwin appreciate the value of the views therein set forth, that he proposed, in a letter to Sir Charles Lyell, to obtain Mr. Wallace’s consent to allow the Essay to be published as soon as possible. Of this step we highly approved, provided Mr. Darwin did not withhold from the public, as he was strongly inclined to do (in favour of Mr. Wallace), the memoir which he had himself written on the same subject, and which, as before stated, one of us had perused in 1844, and the contents of which we had both of us been privy to for many years. On representing this to Mr. Darwin, he gave us permission to make what use we thought proper of his memoir, &c.; and in adopting our present course, of presenting it to the Linnean Society, we have explained to him that we are not solely considering the relative claims to priority of himself and his friend, but the interests of science generally; for we feel it to be desirable that views founded on a wide deduction from facts, and matured by years of reflection, should constitute at once a goal from which others may start, and that, while the scientific world is waiting for the appearance of Mr. Darwin’s complete work, some of the leading results of his labours, as well as those of his able correspondent, should together be laid before the public. We have the honour to be yours very obediently, Charles Lyell. Jos. D. Hooker. J. J. Bennett, Esq., Secretary of the Linnean Society.7 I. Extract from an unpublished Work on Species, by C. Darwin, Esq., consisting of a portion of a Chapter entitled, “On the Variation of Organic Beings in a state of Nature; on the Natural Means of Selection; on the Comparison of Domestic Races and true Species.”8 *

This MS. work was never intended for publication, and therefore was not written with care.—C. D. 1858.

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De Candolle, in an eloquent passage,9 has declared that all nature is at war, one organism with another, or with external nature. |47| Seeing the contented face of nature, this may at first well be doubted; but reflection will inevitably prove it to be true. The war, however, is not constant, but recurrent in a slight degree at short periods, and more severely at occasional more distant periods; and hence its effects are easily overlooked. It is the doctrine of Malthus10 applied in most cases with tenfold force. As in every climate there are seasons, for each of its inhabitants, of greater and less abundance, so all annually breed; and the moral restraint which in some small degree checks the increase of mankind is entirely lost. Even slow-breeding mankind has doubled in twenty-five years; and if he could increase his food with greater ease, he would double in less time. But for animals without artificial means, the amount of food for each species must, on an average, be constant, whereas the increase of all organisms tends to be geometrical, and in a vast majority of cases at an enormous ratio. Suppose in a certain spot there are eight pairs of birds, and that only four pairs of them annually (including double hatches) rear only four young, and that these go on rearing their young at the same rate, then at the end of seven years (a short life, excluding violent deaths, for any bird) there will be 2048 birds, instead of the original sixteen. As this increase is quite impossible, we must conclude either that birds do not rear nearly half their young, or that the average life of a bird is, from accident, not nearly seven years. Both checks probably concur. The same kind of calculation applied to all plants and animals affords results more or less striking, but in very few instances more striking than in man.11 Many practical illustrations of this rapid tendency to increase are on record, among which, during peculiar seasons, are the extraordinary numbers of certain animals; for instance, during the years 1826 to 1828, in La Plata, when from drought some millions of cattle perished, the whole country actually swarmed with mice. Now I think it cannot be doubted that during the breeding-season all the mice (with the exception of a few males or females in excess) ordinarily pair, and therefore that this astounding increase during three years must be attributed to a greater number than usual surviving the first year, and then breeding, and so on till the third year, when their numbers were brought down to their usual limits on the return of wet weather. Where man has introduced plants and animals into a new and favourable country, there are many accounts in how surprisingly few years the whole country has become stocked with them. This increase would |48| necessarily stop as soon as the country was fully stocked; and yet we have every reason to believe, from what is known of wild animals, that all would pair in the spring. In the majority of cases it is most difficult to imagine where the checks fall—though generally, no doubt, on the seeds, eggs, and young; but when we remember how impossible, even in mankind (so much better known than any other animal), it is to infer from repeated casual observations what the average duration of life is, or to discover the different percentage of deaths to births in different countries, we ought to feel no surprise at our being unable to discover where the check falls in any animal or plant. It should always be remembered, that in most cases the checks are recurrent yearly in a small, regular degree, and in an extreme degree during unusually cold, hot, dry, or wet years, according to the constitution of the being in question. Lighten any check in the least degree, and the geometrical powers of increase in every organism will almost instantly increase the average

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number of the favoured species. Nature may be compared to a surface on which rest ten thousand sharp wedges touching each other and driven inwards by incessant blows.12 Fully to realize these views much reflection is requisite. Malthus on man should be studied; and all such cases as those of the mice in La Plata, of the cattle and horses when first turned out in South America, of the birds by our calculation, &c., should be well considered. Reflect on the enormous multiplying power inherent and annually in action in all animals; reflect on the countless seeds scattered by a hundred ingenious contrivances, year after year, over the whole face of the land; and yet we have every reason to suppose that the average percentage of each of the inhabitants of a country usually remains constant. Finally, let it be borne in mind that this average number of individuals (the external conditions remaining the same) in each country is kept up by recurrent struggles against other species or against external nature (as on the borders of the Arctic regions, where the cold checks life), and that ordinarily each individual of every species holds its place, either by its own struggle and capacity of acquiring nourishment in some period of its life, from the egg upwards; or by the struggle of its parents (in short-lived organisms, when the main check occurs at longer intervals) with other individuals of the same or different species. But let the external conditions of a country alter. If in a small degree, the relative proportions of the inhabitants will in most cases simply be slightly changed; but let the number of |49| inhabitants be small, as on an island,13 and free access to it from other countries be circumscribed, and let the change of conditions continue progressing (forming new stations), in such a case the original inhabitants must cease to be as perfectly adapted to the changed conditions as they were originally. It has been shown in a former part of this work, that such changes of external conditions would, from their acting on the reproductive system, probably cause the organization of those beings which were most affected to become, as under domestication, plastic. Now, can it be doubted, from the struggle each individual has to obtain subsistence, that any minute variation in structure, habits, or instincts, adapting that individual better to the new conditions, would tell upon its vigour and health? In the struggle it would have a better chance of surviving; and those of its offspring which inherited the variation, be it ever so slight, would also have a better chance. Yearly more are bred than can survive; the smallest grain in the balance, in the long run, must tell on which death shall fall, and which shall survive. Let this work of selection on the one hand, and death on the other, go on for a thousand generations, who will pretend to affirm that it would produce no effect, when we remember what, in a few years, Bakewell14 effected in cattle, and Western15 in sheep, by this identical principle of selection? To give an imaginary example from changes in progress on an island:—let the organization16 of a canine animal which preyed chiefly on rabbits, but sometimes on hares, become slightly plastic; let these same changes cause the number of rabbits very slowly to decrease, and the number of hares to increase; the effect of this would be that the fox or dog would be driven to try to catch more hares: his organization, however, being slightly plastic, those individuals with the lightest forms, longest limbs, and best eyesight, let the difference be ever so small, would be slightly favoured, and would tend to live longer, and to survive during that time of the year when food was scarcest; they would also rear more young, which

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would tend to inherit these slight peculiarities. The less fleet ones would be rigidly destroyed. I can see no more reason to doubt that these causes in a thousand generations would produce a marked effect, and adapt the form of the fox or dog to the catching of hares instead of rabbits, than that greyhounds can be improved by selection and careful breeding. So would it be with plants under similar circumstances. If the number of individuals of a species with plumed seeds could be increased by greater powers of dissemination within its own area |50| (that is, if the check to increase fell chiefly on the seeds), those seeds which were provided with ever so little more down, would in the long run be most disseminated; hence a greater number of seeds thus formed would germinate, and would tend to produce plants inheriting the slightly better-adapted down.* Besides this natural means of selection, by which those individuals are preserved, whether in their egg, or larval, or mature state, which are best adapted to the place they fill in nature, there is a second agency at work in most unisexual animals, tending to produce the same effect, namely, the struggle of the males for the females. These struggles are generally decided by the law of battle, but in the case of birds, apparently, by the charms of their song, by their beauty or their power of courtship, as in the dancing rock-thrush of Guiana. The most vigorous and healthy males, implying perfect adaptation, must generally gain the victory in their contests. This kind of selection,17 however, is less rigorous than the other; it does not require the death of the less successful, but gives to them fewer descendants. The struggle falls, moreover, at a time of year when food is generally abundant, and perhaps the effect chiefly produced would be the modification of the secondary sexual characters, which are not related to the power of obtaining food, or to defence from enemies, but to fighting with or rivalling other males. The result of this struggle amongst the males may be compared in some respects to that produced by those agriculturists who pay less attention to the careful selection of all their young animals, and more to the occasional use of a choice mate. II. Abstract of a Letter from C. Darwin, Esq., to Prof. Asa Gray, Boston, U.S., dated Down, September 5th, 1857.18 1. It is wonderful what the principle of selection by man, that is the picking out of individuals with any desired quality, and breeding from them, and again picking out, can do. Even breeders have been astounded at their own results. They can act on differences inappreciable to an uneducated eye. Selection has been methodically followed in Europe for only the last half century; but it was occasionally, and even in some degree methodically, followed in the most ancient times. There must have been also a kind of unconscious selection from a remote period, namely in |51| the preservation of the individual animals (without any thought of their offspring) most useful to each race of man in his particular circumstances. The “roguing,” as nurserymen call the destroying of varieties which depart from their type, is a kind of selection. I am convinced that intentional and occasional selection has been the main agent in the production of our domestic races; but however this may be, its great power of modification has been indisputably shown in later times. Selection acts only by the *

I can see no more difficulty in this, than in the planter improving his varieties of the cotton plant.—C. D. 1858.

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accumulation of slight or greater variations, caused by external conditions, or by the mere fact that in generation the child is not absolutely similar to its parent. Man, by this power of accumulating variations, adapts living beings to his wants—may be said to make the wool of one sheep good for carpets, of another for cloth, &c. 2. Now suppose there were a being who did not judge by mere external appearances, but who could study the whole internal organization, who was never capricious, and should go on selecting for one object during millions of generations; who will say what he might not effect? In nature we have some slight variation occasionally in all parts; and I think it can be shown that changed conditions of existence is the main cause of the child not exactly resembling its parents; and in nature geology shows us what changes have taken place, and are taking place. We have almost unlimited time; no one but a practical geologist can fully appreciate this. Think of the Glacial period, during the whole of which the same species at least of shells have existed; there must have been during this period millions on millions of generations. 3. I think it can be shown that there is such an unerring power at work in Natural Selection (the title of my book),19 which selects exclusively for the good of each organic being. The elder De Candolle, W. Herbert,20 and Lyell have written excellently on the struggle for life; but even they have not written strongly enough. Reflect that every being (even the elephant) breeds at such a rate, that in a few years, or at most a few centuries, the surface of the earth would not hold the progeny of one pair. I have found it hard constantly to bear in mind that the increase of every single species is checked during some part of its life, or during some shortly recurrent generation. Only a few of those annually born can live to propagate their kind. What a trifling difference must often determine which shall survive, and which perish! 4. Now take the case of a country undergoing some change. This will tend to cause some of its inhabitants to vary slightly—|52| not but that I believe most beings vary at all times enough for selection to act on them. Some of its inhabitants will be exterminated; and the remainder will be exposed to the mutual action of a different set of inhabitants, which I believe to be far more important to the life of each being than mere climate. Considering the infinitely various methods which living beings follow to obtain food by struggling with other organisms, to escape danger at various times of life, to have their eggs or seeds disseminated, &c. &c., I cannot doubt that during millions of generations individuals of a species will be occasionally born with some slight variation, profitable to some part of their economy. Such individuals will have a better chance of surviving, and of propagating their new and slightly different structure; and the modification may be slowly increased by the accumulative action of natural selection to any profitable extent. The variety thus formed will either coexist with, or, more commonly, will exterminate its parent form. An organic being, like the woodpecker or misseltoe, may thus come to be adapted to a score of contingences—natural selection accumulating those slight variations in all parts of its structure, which are in any way useful to it during any part of its life. 5. Multiform difficulties will occur to every one, with respect to this theory. Many can, I think, be satisfactorily answered. Natura non facit saltum21 answers some of the most obvious. The slowness of the change, and only a very few individuals undergoing

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change at any one time, answers others. The extreme imperfection of our geological records answers others. 6. Another principle, which may be called the principle of divergence, plays, I believe, an important part in the origin of species. The same spot will support more life if occupied by very diverse forms. We see this in the many generic forms in a square yard of turf, and in the plants or insects on any little uniform islet, belonging almost invariably to as many genera and families as species. We can understand the meaning of this fact amongst the higher animals, whose habits we understand. We know that it has been experimentally shown that a plot of land will yield a greater weight if sown with several species and genera of grasses, than if sown with only two or three species. Now, every organic being, by propagating so rapidly, may be said to be striving its utmost to increase in numbers. So it will be with the offspring of any species after it has become diversified into varieties, or subspecies, or true species. And it follows, I think, from the foregoing facts, that the varying offspring of each species will try |53| (only few will succeed) to seize on as many and as diverse places in the economy of nature as possible. Each new variety or species, when formed, will generally take the place of, and thus exterminate its less well-fitted parent. This I believe to be the origin of the classification and affinities of organic beings at all times; for organic beings always seem to branch and sub-branch like the limbs of a tree from a common trunk, the flourishing and diverging twigs destroying the less vigorous—the dead and lost branches rudely representing extinct genera and families. This sketch is most imperfect; but in so short a space I cannot make it better. Your imagination must fill up very wide blanks. C. Darwin. III. On the Tendency of Varieties to depart indefinitely from the Original Type. By Alfred Russel Wallace.22 One of the strongest arguments which have been adduced to prove the original and permanent distinctness of species is, that varieties produced in a state of domesticity are more or less unstable, and often have a tendency, if left to themselves, to return to the normal form of the parent species; and this instability is considered to be a distinctive peculiarity of all varieties, even of those occurring among wild animals in a state of nature, and to constitute a provision for preserving unchanged the originally created distinct species. In the absence or scarcity of facts and observations as to varieties occurring among wild animals, this argument has had great weight with naturalists, and has led to a very general and somewhat prejudiced belief in the stability of species. Equally general, however, is the belief in what are called “permanent or true varieties,”—races of animals which continually propagate their like, but which differ so slightly (although constantly) from some other race, that the one is considered to be a variety of the other. Which is the variety and which the original species, there is generally no means of determining, except in those rare cases in

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which the one race has been known to produce an offspring unlike itself and resembling the other. This, however, would seem quite incompatible with the “permanent invariability of species,” but the difficulty is overcome by assuming that such varieties have strict limits, and can never again vary further from the original type, although they may return to it, which, from the |54| analogy of the domesticated animals, is considered to be highly probable, if not certainly proved. It will be observed that this argument rests entirely on the assumption, that varieties occurring in a state of nature are in all respects analogous to or even identical with those of domestic animals, and are governed by the same laws as regards their permanence or further variation. But it is the object of the present paper to show that this assumption is altogether false, that there is a general principle in nature which will cause many varieties to survive the parent species, and to give rise to successive variations departing further and further from the original type, and which also produces, in domesticated animals, the tendency of varieties to return to the parent form. The life of wild animals is a struggle for existence. The full exertion of all their faculties and all their energies is required to preserve their own existence and provide for that of their infant offspring. The possibility of procuring food during the least favourable seasons, and of escaping the attacks of their most dangerous enemies, are the primary conditions which determine the existence both of individuals and of entire species. These conditions will also determine the population of a species; and by a careful consideration of all the circumstances we may be enabled to comprehend, and in some degree to explain, what at first sight appears so inexplicable—the excessive abundance of some species, while others closely allied to them are very rare. The general proportion that must obtain between certain groups of animals is readily seen. Large animals cannot be so abundant as small ones; the carnivora must be less numerous than the herbivora; eagles and lions can never be so plentiful as pigeons and antelopes; the wild asses of the Tartarian deserts cannot equal in numbers the horses of the more luxuriant prairies and pampas of America. The greater or less fecundity of an animal is often considered to be one of the chief causes of its abundance or scarcity; but a consideration of the facts will show us that it really has little or nothing to do with the matter. Even the least prolific of animals would increase rapidly if unchecked, whereas it is evident that the animal population of the globe must be stationary, or perhaps, through the influence of man, decreasing. Fluctuations there may be; but permanent increase, except in restricted localities, is almost impossible. For example, our own observation must convince us that birds do not go on increasing every year in a geometrical ratio, as they would do, were there not |55| some powerful check to their natural increase. Very few birds produce less than two young ones each year, while many have six, eight, or ten; four will certainly be below the average; and if we suppose that each pair produce young only four times in their life, that will also be below the average, supposing them not to die either by violence or want of food. Yet at this rate how tremendous would be the increase in a few years from a single pair! A simple calculation will show that in fifteen years each pair of birds would have increased to nearly ten millions! whereas we have no reason to believe that the number of the birds of any

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country increases at all in fifteen or in one hundred and fifty years. With such powers of increase the population must have reached its limits, and have become stationary, in a very few years after the origin of each species. It is evident, therefore, that each year an immense number of birds must perish—as many in fact as are born; and as on the lowest calculation the progeny are each year twice as numerous as their parents, it follows that, whatever be the average number of individuals existing in any given country, twice that number must perish annually,—a striking result, but one which seems at least highly probable, and is perhaps under rather than over the truth. It would therefore appear that, as far as the continuance of the species and the keeping up the average number of individuals are concerned, large broods are superfluous. On the average all above one become food for hawks and kites, wild cats and weasels, or perish of cold and hunger as winter comes on. This is strikingly proved by the case of particular species; for we find that their abundance in individuals bears no relation whatever to their fertility in producing offspring. Perhaps the most remarkable instance of an immense bird population is that of the passenger pigeon of the United States, which lays only one, or at most two eggs, and is said to rear generally but one young one. Why is this bird so extraordinarily abundant, while others producing two or three times as many young are much less plentiful? The explanation is not difficult. The food most congenial to this species, and on which it thrives best, is abundantly distributed over a very extensive region, offering such differences of soil and climate, that in one part or another of the area the supply never fails. The bird is capable of a very rapid and long-continued flight, so that it can pass without fatigue over the whole of the district it inhabits, and as soon as the supply of food begins to fail in one place is able to discover a fresh feeding-ground. This example strikingly shows us that the procuring a constant supply |56| of wholesome food is almost the sole condition requisite for ensuring the rapid increase of a given species, since neither the limited fecundity, nor the unrestrained attacks of birds of prey and of man are here sufficient to check it. In no other birds are these peculiar circumstances so strikingly combined. Either their food is more liable to failure, or they have not sufficient power of wing to search for it over an extensive area, or during some season of the year it becomes very scarce, and less wholesome substitutes have to be found; and thus, though more fertile in offspring, they can never increase beyond the supply of food in the least favourable seasons. Many birds can only exist by migrating, when their food becomes scarce, to regions possessing a milder, or at least a different climate, though, as these migrating birds are seldom excessively abundant, it is evident that the countries they visit are still deficient in a constant and abundant supply of wholesome food. Those whose organization does not permit them to migrate when their food becomes periodically scarce, can never attain a large population. This is probably the reason why woodpeckers are scarce with us, while in the tropics they are among the most abundant of solitary birds. Thus the house sparrow is more abundant than the redbreast, because its food is more constant and plentiful,—seeds of grasses being preserved during the winter, and our farm-yards and stubble-fields furnishing an almost inexhaustible supply. Why, as a general rule, are aquatic, and especially sea birds, very numerous in individuals? Not because they are more prolific than others, generally the contrary; but because their food never fails, the sea-shores and

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river-banks daily swarming with a fresh supply of small mollusca and crustacea. Exactly the same laws will apply to mammals. Wild cats are prolific and have few enemies; why then are they never as abundant as rabbits? The only intelligible answer is, that their supply of food is more precarious. It appears evident, therefore, that so long as a country remains physically unchanged, the numbers of its animal population cannot materially increase. If one species does so, some others requiring the same kind of food must diminish in proportion. The numbers that die annually must be immense; and as the individual existence of each animal depends upon itself, those that die must be the weakest—the very young, the aged, and the diseased,—while those that prolong their existence can only be the most perfect in health and vigour—those who are best able to obtain food regularly, and avoid their numerous enemies. It is, as we commenced by remarking, “a struggle for existence,” in |57| which the weakest and least perfectly organized must always succumb. Now it is clear that what takes place among the individuals of a species must also occur among the several allied species of a group,—viz. that those which are best adapted to obtain a regular supply of food, and to defend themselves against the attacks of their enemies and the vicissitudes of the seasons, must necessarily obtain and preserve a superiority in population; while those species which from some defect of power or organization are the least capable of counteracting the vicissitudes of food, supply, &c., must diminish in numbers, and, in extreme cases, become altogether extinct. Between these extremes the species will present various degrees of capacity for ensuring the means of preserving life; and it is thus we account for the abundance or rarity of species. Our ignorance will generally prevent us from accurately tracing the effects to their causes; but could we become perfectly acquainted with the organization and habits of the various species of animals, and could we measure the capacity of each for performing the different acts necessary to its safety and existence under all the varying circumstances by which it is surrounded, we might be able even to calculate the proportionate abundance of individuals which is the necessary result. If now we have succeeded in establishing these two points—1st, that the animal population of a country is generally stationary, being kept down by a periodical deficiency of food, and other checks; and, 2nd, that the comparative abundance or scarcity of the individuals of the several species is entirely due to their organization and resulting habits, which, rendering it more difficult to procure a regular supply of food and to provide for their personal safety in some cases than in others, can only be balanced by a difference in the population which have to exist in a given area—we shall be in a condition to proceed to the consideration of varieties, to which the preceding remarks have a direct and very important application. Most or perhaps all the variations from the typical form of a species must have some definite effect, however slight, on the habits or capacities of the individuals. Even a change of colour might, by rendering them more or less distinguishable, affect their safety; a greater or less development of hair might modify their habits. More important changes, such as an increase in the power or dimensions of the limbs or any of the external organs, would more or less affect their mode of procuring food or the range of |58| country which they inhabit. It is also evident that most changes would affect, either favourably or adversely, the powers

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of prolonging existence. An antelope with shorter or weaker legs must necessarily suffer more from the attacks of the feline carnivora; the passenger pigeon with less powerful wings would sooner or later be affected in its powers of procuring a regular supply of food; and in both cases the result must necessarily be a diminution of the population of the modified species. If, on the other hand, any species should produce a variety having slightly increased powers of preserving existence, that variety must inevitably in time acquire a superiority in numbers. These results must follow as surely as old age, intemperance, or scarcity of food produce an increased mortality. In both cases there may be many individual exceptions; but on the average the rule will invariably be found to hold good. All varieties will therefore fall into two classes—those which under the same conditions would never reach the population of the parent species, and those which would in time obtain and keep a numerical superiority. Now, let some alteration of physical conditions occur in the district—a long period of drought, a destruction of vegetation by locusts, the irruption of some new carnivorous animal seeking “pastures new”—any change in fact tending to render existence more difficult to the species in question, and tasking its utmost powers to avoid complete extermination; it is evident that, of all the individuals composing the species, those forming the least numerous and most feebly organized variety would suffer first, and, were the pressure severe, must soon become extinct. The same causes continuing in action, the parent species would next suffer, would gradually diminish in numbers, and with a recurrence of similar unfavourable conditions might also become extinct. The superior variety would then alone remain, and on a return to favourable circumstances would rapidly increase in numbers and occupy the place of the extinct species and variety. The variety would now have replaced the species, of which it would be a more perfectly developed and more highly organized form. It would be in all respects better adapted to secure its safety, and to prolong its individual existence and that of the race. Such a variety could not return to the original form; for that form is an inferior one, and could never compete with it for existence. Granted, therefore, a “tendency” to reproduce the original type of the species, still the variety must ever remain preponderant in numbers, and under adverse physical conditions again alone survive. |59| But this new, improved, and populous race might itself, in course of time, give rise to new varieties, exhibiting several diverging modifications of form, any of which, tending to increase the facilities for preserving existence, must, by the same general law, in their turn become predominant. Here, then, we have progression and continued divergence deduced from the general laws which regulate the existence of animals in a state of nature, and from the undisputed fact that varieties do frequently occur. It is not, however, contended that this result would be invariable; a change of physical conditions in the district might at times materially modify it, rendering the race which had been the most capable of supporting existence under the former conditions now the least so, and even causing the extinction of the newer and, for a time, superior race, while the old or parent species and its first inferior varieties continued to flourish. Variations in unimportant parts might also occur, having no perceptible effect on the life-preserving powers; and the varieties so furnished might run a course parallel with the parent species, either giving rise to further variations or returning to

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the former type. All we argue for is, that certain varieties have a tendency to maintain their existence longer than the original species, and this tendency must make itself felt; for though the doctrine of chances or averages can never be trusted to on a limited scale, yet, if applied to high numbers, the results come nearer to what theory demands, and, as we approach to an infinity of examples, become strictly accurate. Now the scale on which nature works is so vast—the numbers of individuals and periods of time with which she deals approach so near to infinity, that any cause, however slight, and however liable to be veiled and counteracted by accidental circumstances, must in the end produce its full legitimate results. Let us now turn to domesticated animals, and inquire how varieties produced among them are affected by the principles here enunciated. The essential difference in the condition of wild and domestic animals is this,—that among the former, their well-being and very existence depend upon the full exercise and healthy condition of all their senses and physical powers, whereas, among the latter, these are only partially exercised, and in some cases are absolutely unused. A wild animal has to search, and often to labour, for every mouthful of food—to exercise sight, hearing, and smell in seeking it, and in avoiding dangers, in procuring shelter from the inclemency of the seasons, and in providing for the subsistence and safety of its offspring. There is no muscle of |60| its body that is not called into daily and hourly activity; there is no sense or faculty that is not strengthened by continual exercise. The domestic animal, on the other hand, has food provided for it, is sheltered, and often confined, to guard it against the vicissitudes of the seasons, is carefully secured from the attacks of its natural enemies, and seldom even rears its young without human assistance. Half of its senses and faculties are quite useless; and the other half are but occasionally called into feeble exercise, while even its muscular system is only irregularly called into action. Now when a variety of such an animal occurs, having increased power or capacity in any organ or sense, such increase is totally useless, is never called into action, and may even exist without the animal ever becoming aware of it. In the wild animal, on the contrary, all its faculties and powers being brought into full action for the necessities of existence, any increase becomes immediately available, is strengthened by exercise, and must even slightly modify the food, the habits, and the whole economy of the race. It creates as it were a new animal, one of superior powers, and which will necessarily increase in numbers and outlive those inferior to it. Again, in the domesticated animal all variations have an equal chance of continuance; and those which would decidedly render a wild animal unable to compete with its fellows and continue its existence are no disadvantage whatever in a state of domesticity. Our quickly fattening pigs, short-legged sheep, pouter pigeons, and poodle dogs could never have come into existence in a state of nature, because the very first step towards such inferior forms would have led to the rapid extinction of the race; still less could they now exist in competition with their wild allies. The great speed but slight endurance of the race horse, the unwieldy strength of the ploughman’s team, would both be useless in a state of nature. If turned wild on the pampas, such animals would probably soon become extinct, or under favourable circumstances might each lose those extreme qualities which would never be called into action, and in a few generations would revert to a common type, which must be

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that in which the various powers and faculties are so proportioned to each other as to be best adapted to procure food and secure safety,—that in which by the full exercise of every part of his organization the animal can alone continue to live. Domestic varieties, when turned wild, must return to something near the type of the original wild stock, or become altogether extinct. |61| We see, then, that no inferences as to varieties in a state of nature can be deduced from the observation of those occurring among domestic animals. The two are so much opposed to each other in every circumstance of their existence, that what applies to the one is almost sure not to apply to the other. Domestic animals are abnormal, irregular, artificial; they are subject to varieties which never occur and never can occur in a state of nature: their very existence depends altogether on human care; so far are many of them removed from that just proportion of faculties, that true balance of organization, by means of which alone an animal left to its own resources can preserve its existence and continue its race. The hypothesis of Lamarck23—that progressive changes in species have been produced by the attempts of animals to increase the development of their own organs, and thus modify their structure and habits—has been repeatedly and easily refuted by all writers on the subject of varieties and species, and it seems to have been considered that when this was done the whole question has been finally settled; but the view here developed renders such an hypothesis quite unnecessary, by showing that similar results must be produced by the action of principles constantly at work in nature. The powerful retractile talons of the falconand the cat-tribes have not been produced or increased by the volition of those animals; but among the different varieties which occurred in the earlier and less highly organized forms of these groups, those always survived longest which had the greatest facilities for seizing their prey. Neither did the giraffe acquire its long neck by desiring to reach the foliage of the more lofty shrubs, and constantly stretching its neck for the purpose, but because any varieties which occurred among its antitypes with a longer neck than usual at once secured a fresh range of pasture over the same ground as their shorter-necked companions, and on the first scarcity of food were thereby enabled to outlive them. Even the peculiar colours of many animals, especially insects, so closely resembling the soil or the leaves or the trunks on which they habitually reside, are explained on the same principle; for though in the course of ages varieties of many tints may have occurred, yet those races having colours best adapted to concealment from their enemies would inevitably survive the longest. We have also here an acting cause to account for that balance so often observed in nature,—a deficiency in one set of organs always being compensated by an increased development of some others— powerful wings accompanying weak |62| feet, or great velocity making up for the absence of defensive weapons; for it has been shown that all varieties in which an unbalanced deficiency occurred could not long continue their existence. The action of this principle is exactly like that of the centrifugal governor of the steam engine, which checks and corrects any irregularities almost before they become evident; and in like manner no unbalanced deficiency in the animal kingdom can ever reach any conspicuous magnitude, because it would make itself felt at the very first step, by rendering existence difficult and extinction almost sure soon to follow. An origin such as is here advocated will also agree with the

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peculiar character of the modifications of form and structure which obtain in organized beings—the many lines of divergence from a central type, the increasing efficiency and power of a particular organ through a succession of allied species, and the remarkable persistence of unimportant parts such as colour, texture of plumage and hair, form of horns or crests, through a series of species differing considerably in more essential characters. It also furnishes us with a reason for that “more specialized structure” which Professor Owen states to be a characteristic of recent compared with extinct forms, and which would evidently be the result of the progressive modification of any organ applied to a special purpose in the animal economy. We believe we have now shown that there is a tendency in nature to the continued progression of certain classes of varieties further and further from the original type—a progression to which there appears no reason to assign any definite limits—and that the same principle which produces this result in a state of nature will also explain why domestic varieties have a tendency to revert to the original type. This progression, by minute steps, in various directions, but always checked and balanced by the necessary conditions, subject to which alone existence can be preserved, may, it is believed, be followed out so as to agree with all the phenomena presented by organized beings, their extinction and succession in past ages, and all the extraordinary modifications of form, instinct, and habits which they exhibit. Ternate, February, 1858.

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CD’s theory of evolution by natural selection was first published in this paper. Two documents by CD, together with the essay by the naturalist and collector Alfred Russel Wallace (1823–1913), were read in the absence of both authors at a meeting of the Linnean Society on 1 July 1858. Both Charles Lyell and Joseph Dalton Hooker were present. See CCD7. CD later published his evolutionary views more fully in Origin (1859). The entire article was reprinted as: Three papers on the tendency of species to form varieties; and on the perpetuation of varieties and species by natural means of selection. Zoologist 16 (1858): 6263–6308. This manuscript, DAR7. (1–189), was later published in Foundations (1909). (DO) Hooker seems to have first read the Essay in January 1847. See CCD4: 11 note 5. The letter was in fact dated 5 September [1857] as correctly given below. CD drafted this memorandum (DAR6.51) and had a fair copy made by his copyist the school teacher Ebenezer Norman. (DO) The fair copy was sent to Asa Gray on 5 September 1857. See CCD6: 445–50. CD later sent his draft to Lyell and Hooker in June 1858 for inclusion in this paper. The draft is transcribed in CCD7, appendix III. For Wallace’s recollections of writing this essay see Wallace 1905, 1: 358–63. (DO) John Joseph Bennett (1801–75), botanist and assistant keeper of the Banksian herbarium and library at the British Museum, 1827–58, then keeper, 1858–70. This was derived from Chapter II of the 1844 essay DAR7. (1–189). (DO) Quoted in Lyell 1837, 2: 131: “All the plants of a given country,” says Decandolle in his usual spirited style, “are at war one with another. The first which establish themselves by chance in a particular spot, tend, by the mere occupancy of space, to exclude other species—the greater choke the smaller, the longest livers replace those which last for a shorter period, the more prolific gradually make themselves masters of the ground, which species multiplying more slowly would otherwise fill.” The original reference is from Candolle 1820, p. 384. Thomas Robert Malthus (1766–1834), clergyman and political economist, first professor of history and political economy at the East India Company College, Haileybury, 1805–34. He argued that

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1859. [Letter on the collections of the British Museum.]

human population growth, unless somehow checked, would necessarily outstrip food production because he believed population growth was geometric (i.e. 1, 2, 4, 8, 16, etc.), whereas food production would grow at an arithmetic rate (i.e. 1, 2, 3, 4, 5, etc.). Darwin refers to Malthus 1826. On Malthus and Malthusianism in CD’s context see Winch 2001. Compare with Origin pp. 64–5, and 6th ed., p. 80. (DO) This simile was later used in the first edition of Origin p. 67 but removed from all subsequent editions. See Origin pp. 104, 292, and 6th ed., pp. 127, 429. Robert Bakewell (1725–95), prominent farmer and stock breeder at Dishley, Leicestershire. See Youatt 1834. Charles Callis Western (1767–1844), politician, agriculturist and sheep breeder. See Origin p. 90 and 6th ed., p. 110. Sexual selection, as it was called in Origin p. 88. See CCD6: 445–50. This abstract is CD’s enclosure to Gray, rather than the letter itself. CD never completed this book. Instead he published an ‘abstract’ of it, i.e. Origin. The first two chapters of the unpublished book became Variation (1868). The following eight and a half chapters were published in 1975 by Robert Stauffer as Natural selection. William Herbert (1778–1847), Dean of Manchester, naturalist, classical scholar and linguist who was known for his work on plant hybridisation. Latin expression meaning ‘Nature does not make a leap’. CD believed it derived from Linnaeus, see Natural selection p. 354. Linnaeus 1751, Sect. 77 reads: Methodi Naturalis Fragmenta studiose inquirenda sunt. Primum & ultimum hoc in Botanicis desideratum est. Natura non facit saltus. Plantae omnes utrinque affinitatem monstrant, uti Territorium in Mappa geographica. English translation: The fragments of natural method are to be closely investigated. This is the first and last desideratum in botanical studies. Nature does not make leaps. All plants show an affinity on either side, like a territory on a geographical map. See Fishburn 2004, appendix B for a survey of the history of this and similar adages. Wallace, a correspondent of CD’s, sent a (now lost) letter in mid-June 1858 from the Moluccas with this essay enclosed. Wallace described his letter in Wallace 1905, 1: 363. See CCD7. CD and Wallace later became loyal friends. Lamarck 1809. Lamarck’s theory of biological transmutation or evolution was well-known to nineteenth-century naturalists. Very often, however, it was misrepresented in the English-speaking world, as Wallace did here, by representing it as driven by the will of individual organisms.

1859. [Letter on the collections of the British Museum.] In Northcote, S., Further communications by architect and officers of British Museum on enlargement of building: plan. Parliamentary Papers, Accounts and Papers 1859 Session 1, paper number (126) (126-I), vol. XIV.51 (11 March): 11. F1934 Down, Bromley, Kent, 19 June. [1858] My dear Sir Roderick, I have just received your note. Unfortunately I cannot attend at the British Museum on Monday. I do not suppose my opinion on the subject of your note can be of any value, as I have not much considered the subject, or had the advantage of discussing it with other naturalists. But my impression is, that there is much weight in what you say about not breaking up the natural history collection of the British Museum. I think a national

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collection ought to be in London. I can, however, see that some weighty arguments might be advanced in favour of Kew, owing to the immense value of Sir W. Hooker’s1 collection and library; but these are private property, and I am not aware that there is any certainty of their always remaining at Kew. Had this been the case, I should have thought that the botanical collection might have been removed there, without endangering the other branches of the collections. But I think it would be the greatest evil which could possibly happen to natural science in this country, if the other collections were ever to be removed from the British Museum and library. Pray believe me, Yours, &c. (signed) Ch. Darwin.2

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William Jackson Hooker (1785–1865), botanist, Regius professor of botany, Glasgow University, 1820–41, first director of the Royal Botanic Gardens, Kew, 1841–65. Father of J. D. Hooker. As a trustee of the British Museum Murchison petitioned against the removal of the natural history collections from Bloomsbury and included letters from Lyell and CD. The memorial, with CD’s signature, was presented to the financial secretary to the Treasury, George Alexander Hamilton (1802–71), at the Treasury Chambers in July 1858 and was published as Darwin 1858, F1942 (p. 269). See CCD7: 112–13; 272.

1859. Coleoptera at Down. Entomologist’s weekly Intelligencer 6: 99. F1703 We three very young collectors have lately taken, in the parish of Down, six miles from Bromley, Kent, the following beetles, which we believe to be rare, namely, Licinus silphoides, Panagus 4-pustulatus and Clytus mysticus.1As this parish is only fifteen miles from London, we have thought that you might think it worth while to insert this little notice in the ‘Intelligencer.’—Francis, Leonard & Horace Darwin.2

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Current names: Licinus silphoides (Coleoptera, Carabidae), Exochomus quadripustulatus (Coleoptera, Coccinellidae), Anaglyptus mysticus (Coleoptera, Cerambycidae). Signed by Francis (1848–1925), Leonard (1850–1943) and Horace Darwin (1851–1928) who were 10, 8 and 7 years of age. Francis Darwin recalled in LL2: 140: ‘[CD] sent a short notice to the ‘Entomologist’s Weekly Intelligencer,’ June 25th, 1859, … signed by three of his boys, but was clearly not written by them. I have a vivid recollection of the pleasure of turning out my bottle of dead beetles for my father to name, and the excitement, in which he fully shared, when any of them proved to be uncommon ones.’

1860. Cross-bred plants. Gardeners’ Chronicle and Agricultural Gazette no. 3 (21 January): 49. F1704 I hope that some of your readers will respond to Mr. Westwood’s1 wish, and give any information which they may possess on the permanence of cross-bred plants and animals.

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Will Mr. Westwood be so good as to give a reference to any account of the variability of the Swedish Turnip?2 I did not even know that it was reputed to be a cross-bred production. I am aware that this is supposed to be the case with some Turnips; but I have searched in vain for any authentic history of their origin. No one, I believe, doubts that cross-bred productions tend to revert in various degrees to either parent for many generations; some say for a dozen, others for a score or even more generations. But cannot breeders adduce some cases of crossed breeds of sheep and pigs (such as the Shropshire or Oxford sheep,3 or Lord Harborough’s pigs)4 which are now true? With respect to the Cottagers’ Kale,5 I was so much surprised at the accounts of its trueness that I procured seed from the raisers; but in my soil the plants were far from presenting a uniform appearance. In addition to the tendency to reversion to either parent form, it is almost universally asserted that cross-bred productions are highly variable, and often display characters not observed in either parent. I do not wish to dispute this common belief, but I suspect it would puzzle any one to adduce satisfactory cases; and certainly Gärtner has advanced a mass of evidence on the opposite side.6 I am not at all surprised at Mr. Westwood demurring to the belief that occasionally crossing the strain is advantageous or necessary with productions in a state of nature. The subject is only just alluded to in my volume on the “Origin of Species.”7 I do not pretend that I can prove the truth of the doctrine; but I feel sure that many important facts and arguments can be adduced in its favour. The ill effects of close inter-breeding between the nearest relations, especially if exposed to the same conditions of life, would be, I believe, the same under Nature as under domestication,—namely, some degree of sterility and weakness of constitution. Variability arises from quite independent causes, and is to a certain extent counteracted in its early stages by the free crossing of the individuals of the same species. Mr. Westwood misunderstands me if he supposes that it is my opinion that the Ibis, for instance, keeps true to its kind “by occasional crosses with individuals of the same species which have not sprung from the same grandfather or great-grandfather.” I only believe that if individuals of the Ibis did vary, such crosses would tend to keep the species true; and further, if the young from a single pair increased so slowly that they all continued to inhabit the same small district, and if brothers and sisters often united during successive generations, then that the Ibis would rapidly deteriorate in fertility and constitution. Mr. Westwood advances the hive-bee, as probably a case of constant intercrossing. Andrew Knight,8 however, who specially attended to this point, has published his belief (whether founded on sufficient evidence I will not pretend to say) that the queen-bee commonly unites with a drone from another community. Charles Darwin, Down, Bromley, Kent.9

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John Obadiah Westwood (1805–93), entomologist and palaeographer. CD refers to Westwood 1860, in which it is claimed that plants of hybrid or mongrel origin will ultimately revert to their original type which contradicts the ‘theory of progressive development’ as in CD’s recent book Origin. For more detail on the contents of this letter see CCD8: 33–4. Westwood mentioned that the Swedish turnip was rapidly deteriorating despite efforts to continue breeding it. See Variation 2: 95–6.

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Robert Sherard, Earl of Harborough (1798–1859), known for a breed of pigs called Improved Essex. Common kale crossed with Brussels sprouts, see Variation 1: 324. Gärtner 1849. Origin, pp. 96–7. Knight 1828, p. 319. Westwood replied in Gardeners’ Chronicle, 11 February 1860, p. 122.

1860. Natural selection. Gardeners’ Chronicle and Agricultural Gazette no. 16 (21 April): 362–3. F1705 I have been much interested by Mr. Patrick Matthew’s communication in the Number of your Paper, dated April 7th. I freely acknowledge that Mr. Matthew has anticipated by many years the explanation which I have offered of the origin of species, under the name of natural selection. I think |363| that no one will feel surprised that neither I, nor apparently any other naturalist, had heard of Mr. Matthew’s views, considering how briefly they are given, and that they appeared in the appendix to a work on Naval Timber and Arboriculture. I can do no more than offer my apologies to Mr. Matthew for my entire ignorance of his publication. If another edition of my work is called for, I will insert a notice to the foregoing effect. Charles Darwin, Down, Bromley, Kent.1

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This is CD’s reply to the letter written by the Scottish author on political and agricultural subjects, Patrick Matthew (1790–1874), in the Gardeners’ Chronicle (Matthew 1860) in which Matthew claimed to have preceded CD as the discoverer of natural selection in the appendix to Matthew 1831. CD later included Matthew among his predecessors in the ‘Historical sketch’ published in the 3d and later eds. of Origin. See CCD8: 156.

1860. Intercourse between common and Ligurian bees. Cottage Gardener and Country Gentleman 24 (29 May): 143. F1814 “A Devonshire Bee-Keeper”1 states (page 94)2 that he caught a common drone entering one of his hives of the pure Ligurian stock.3 Will he have the kindness to state at what distance in a straight line there are hives of the common bee? I believe it is not known how far the drones commonly wander from their own hive. Andrew Knight believed, as stated in the “Philosophical Transactions,”4 that the queen was seldom fertilised by her own bloodrelations, the drones of her own hive. Does “A Devonshire Bee-Keeper,” who seems to be so conversant with the habits of bees, believe in this doctrine of Andrew Knight?—C. D.5

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‘Devonshire bee-keeper’ was the pen name of Thomas White Woodbury (1818–71). See CCD8: 199. [Woodbury] 1860, p. 94. A well-known gentle strain of bees (Apis mellifera ligustica). Knight 1828, p. 307. Woodbury’s reply, dated 24 May, immediately followed CD’s letter. Woodbury believed that ‘females among bees are very generally fertilised by the offspring of the same mother’, p. 143.

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1860. Fertilisation of British orchids by insect agency. Gardeners’ Chronicle and Agricultural Gazette no. 23 (9 June): 528. F1706 I should be extremely much obliged to any person living where the Bee or Fly Orchis is tolerably common, if he will have the kindness to make a few simple observations on their manner of fertilisation.1 To render the subject clear to those who know nothing of botany, I must briefly describe what takes place in our common British Orchids. The pollen-grains form two pear-shaped masses; each borne on a foot-stalk, with a sticky gland at the end. The pollen masses are hidden in little pouches open in front. When an insect visits a flower, it almost necessarily, owing to the position of the parts, uncovers and touches the sticky glands. These firmly adhere to the head or body of the insect, and thus the pollen-masses are drawn out of their pouches, are dragged over the humid stigmatic surface, and the plant is fertilised. So beautifully are the relative degrees of adhesiveness of the gland, and of the grains of pollen to each other and to the stigmatic surface mutually adapted, that an insect with an adherent pollen-mass will drag it over the stigmas of several flowers, and leave granules of pollen on each. The contrivances by which the sticky glands are prevented from drying, and so kept always viscid and ready for action, is even still more curious; they lie suspended (at least in the two species which I have examined) in a little hemispherical cup, full of liquid, and formed of such delicate membrance, that the side projecting over the gangway into the nectary is ruptured transversely and depressed by the slightest touch; and then the glands, sticky and fresh out of their bath, immediately and almost inevitably come into contact with and adhere to the body which has just ruptured the cup. It is certain that with most of our common Orchids insects are absolutely necessary for their fertilisation; for without their agency, the pollen-masses are never removed and wither within their pouches. I have proved this in the case of Orchis morio and mascula by covering up plants under a bell-glass, leaving other adjoining plants uncovered; in the latter I found every morning, as the flowers became fully expanded, some of the pollen masses removed, whereas in the plants under the glass all the pollen-masses remained enclosed in their pouches.2 Robert Brown, however, has remarked that the fact of all the capsules in a dense spike of certain Orchids producing seed seems hardly reconcileable with their fertilisation having been accidentally effected by insects.3 But I could give many facts showing how effectually insects do their work; two cases will here suffice; in a plant of Orchis maculata with 44 flowers open, the 12 upper ones, which were not quite mature, had not one pollen-mass removed, whereas every one of the 32 lower flowers had one or both pollen-masses removed; in a plant of Gymnadenia conopsea with 54 open flowers, 52 had their pollenmasses removed. I have repeatedly observed in various Orchids grains of pollen, and in one case three whole pollen-masses on the stigmatic surface of a flower, which still retained its own two pollen-masses; and as often, or even oftener, I have found flowers with the pollen-masses removed, but with no pollen on their stigmas. These facts clearly show that each flower is often, or even generally, fertilised by the pollen brought by insects from another flower or plant. I may add that after observing our Orchids during many years, I have never seen a bee or any other diurnal insect (excepting once a butterfly) visit them; therefore

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I have no doubt that moths are the priests who perform the marriage ceremony. The structure, indeed, of some Orchids leads to this same conclusion; for no insect without a very long and extremely fine proboscis could possibly reach the nectar at the bottom of the extremely long and narrow nectary of the Butterfly-Orchis; and entomologists have occasionally captured moths with pollen-masses adhering to them. If any entomologist reads this, and can remember positively having caught a moth thus furnished, I hope he will give its name, and describe exactly to which part of the moth’s body the sticky gland adhered. We may now turn to the genus Ophrys; in the Fly Orchis (Ophrys muscifera), the pollenmasses, furnished with sticky glands, do not naturally fall out of their pouches, nor can they be shaken out; so that insect-agency is necessary, as with the species of the other genera, for their fertilisation. But insects here do their work far less effectually than with common Orchids; during several years, previously to 1858, I kept a record of the state of the pollen-masses in well-opened flowers of those plants which I examined, and out of 102 flowers I found either one or both pollen-masses removed in only 13 flowers. But in 1858 I found 17 plants growing near each other and bearing 57 flowers and of these 30 flowers had one or both pollen-masses removed; and as all the remaining 27 flowers were the upper and younger flowers, they probably would subsequently have had most of their pollen-masses removed, and thus have been fertilised. I should much like to hear how the case stands with the Fly Orchis in other districts; for it seems a strange fact that a plant should grow pretty well, as it does in this part of Kent, and yet during several years seldom be fertilised. We now come to the Bee Orchis (Ophrys apifera), which presents a very different case; the pollen masses are furnished with sticky glands, but differently from in all the foregoing Orchids, they naturally fall out of their pouches; and from being of the proper length, though still retained at the gland-end, they fall on the stigmatic surface, and the plant is thus self-fertilised. During several years I have examined many flowers, and never in a single instance found even one of the pollen-masses carried away by insects, or ever saw the flower’s own pollen-masses fail to fall on the stigma. Robert Brown consequently believed that the visits of insects would be injurious to the fertilisation of this Orchis; and rather fancifully imagined that the flower resembled a bee in order to deter their visits. We must admit that the natural falling out of the pollen-masses of this Orchis is a special contrivance for its self-fertilisation; [= self-pollination] and as far as my experience goes, a perfectly successful contrivance, for I have always found this plant self-fertilised; nevertheless a long course of observation has made me greatly doubt whether the flowers of any kind of plant are for a perpetuity of generations fertilised by their own pollen. And what are we to say with respect to the sticky glands of the Bee Orchis, the use and efficiency of which glands in all other British Orchids are so manifest? Are we to conclude that this one species is provided with these organs for no use? I cannot think so; but would rather infer that, during some years or in some other districts, insects do visit the Bee Orchis and occasionally transport pollen from one flower to another, and thus give it the advantage of an occasional cross. We have seen that the Fly Orchis is not in this part of the country by any means sufficiently often visited by insects, though the visits of insects are indispensable to its

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fertilisation. So with the Bee Orchis, though its self-fertilisation is specially provided for, it may not exist here under the most favourable conditions of life; and in other districts or during particular seasons it may be visited by insects, and in this case, as its pollen masses are furnished with sticky glands, it would almost certainly receive the benefit of an occasional cross impregnation. It is this curious apparent contradiction in the structure of the Bee Orchis—one part, namely the sticky glands, being adapted for fertilisation by insect agency—another part, namely the natural falling out of the pollen-masses, being adapted for self-fertilisation without insect agency—which makes me anxious to hear what happens to the pollen-masses of the Bee Orchis in other districts or parts of England. I should be extremely much obliged to any one who will take the trouble to observe this point and to communicate the result to the Gardeners’ Chronicle or to me. Charles Darwin, Down, Bromley, Kent.

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This article was reprinted in Entomologist’s weekly Intelligencer 8 (7, 14 July 1860): 93–94, 102–103. See CCD8: 235–7. See Natural selection, pp. 65–6. Brown 1832. See Orchids, pp. 63–72.

1860. Do the Tineina or other small moths suck flowers, and if so what flowers? Entomologist’s weekly Intelligencer 8 (30 June): 103. F1708 I once saw several individuals of a small moth apparently eating the pollen of the Mercurialis; is this physically possible? I have during several years watched the smaller clovers, such as Trifolium procumbens, and the Vicia hirsuta which has such extremely minute flowers, and I never saw a bee visit them. I am, however, aware from experience that it is very difficult to assert that bees do not visit any particular kind of plant. As Mr. F. Bond1 informs me that he has often seen moths visiting papilionaceous flowers, even such small ones as those of the trefoil, it has occurred to me that small moths may suck the flowers of T. procumbens and of V. hirsuta. From analogy we must believe that the smaller clovers secrete nectar; and it does not seem probable that the nectar would be wasted. I should esteem it a great favour if any Lepidopterists would communicate their experience on this point.—Charles Darwin, Down, Bromley, Kent. (In reply to Mr. Darwin’s enquiry we may observe that very many of the Tineina are provided with tongues, and that these appendages are naturally used in extracting the sweets of flowers. It is no uncommon sight to see an Umbellifer swarming with the pretty little Glyphipteryx Fischeriella, each with its proboscis extended sucking at the flowers. The Depressariae, as is notorious to every collector of Noctuae, come very freely to sugar, and no doubt naturally visit flowers. But the fertilization of flowers may be accomplished by insects in another way. Many species oviposit on the blooming flowers; they do not deposit all their eggs on a single plant, but sparingly a |104| few here and a few there; a female protruding her ovipositor down

1861. Note on the achenia of Pumilio argyrolepis

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the corolla of a flower, and then flying off to repeat the operation elsewhere may herself be “the priest who performs the marriage ceremony.”)

1

Frederick Bond (1811–89), entomologist and ornithologist. On this letter see CCD8: 261–2.

1860. Irritability of Drosera. Gardeners’ Chronicle and Agricultural Gazette no. 38 (22 September): 853. F1813 In Lindley’s Vegetable Kingdom (p. 433)1 it is stated that the leaves of Drosera lunata2 “close upon flies and other insects that happen to alight upon them.” Can you refer me to any published account of the movement of the viscid hairs or leaves of this Indian Drosera? C. R. Darwin, Down, Sept. 15. (Dr. Royle3 is the authority for the statement in question. In his Illustrations of Himalayan Botany there is the following passage:—“D. lunata occurs in the mountains from Silhet to the Sutlej. This I have found in the small valleys enclosed within the different lateral projections of the Mussooree range, where the ground is rather flat, and the soil moist. In such situations it springs up and flowers in considerable quantities, but only during the rainy season, when the thermometer has a range of not more than 10°, between 60° and 70°, and the hygrometer always indicates a degree of moisture approaching that of saturation. This species, which in my MSS. Catalogue I had named D. muscipula, from the glandular cilias of its viscous leaves closing upon flies and other insects which happen to light upon them, is remarkable, as in this respect resembling Dionæa muscipula, which is placed in the same natural family.”)4

1 2 3 4

Lindley 1846. For more detail on this letter see CCD8: 357. Drosera = Sundews. John Forbes Royle (1799–1858), surgeon and naturalist. Royle 1839, 1: 75.

1861. Note on the achenia of Pumilio argyrolepis. Gardeners’ Chronicle and Agricultural Gazette no. 1 (5 January): 4–5. F1709 Mr. James Drummond1 sent me a packet of seeds of this plant from Swan River, with the following memorandum:—“The achenia2 of several small composite plants, more especially of that above named, are blown about by the wind till a shower of rain falls, when they attach themselves by a gummy matter to the soil by their lower ends, at the same time setting themselves perfectly upright. They ornament many a barren spot in this country throughout the dry season, and they are not easily removed even when the ground is flooded by thunder storms.” The achenia of the Pumilio3 are singularly-shaped bodies; the calyx (pappus) consists generally of nine scales or sepals, expanded like a flower, with each sepal beautifully

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1861. Note on the achenia of Pumilio argyrolepis

ornamented by branching lines; the lower part, including the seed, is bent towards one side (see Fig. 1) at nearly right angles, and somewhat resembles a human foot in shape. The upper side or instep of this foot is smooth, but the toe and the sole, which is about 1–25th of an inch in length, is covered (see Fig. 2) with from 30 to 40 imbricated little bladders. Each bladder is oval and 1.200th of an inch in length, and is formed of thin structureless membrane, enclosing a hard ball of dry mucus or matter which becomes adhesive when moistened. The sole or the achenium is pitted where the bladders are attachedf4 |5| but these do not open into its interior. When the achenia are placed in water or on a damp surface, the bladders in a few minutes all burst longitudinally and discharge their contents, rendering a large drop of water very viscid. This viscid drop does not diffuse itself throughout the water, like gum, but remains surrounding the achenium. When dried it becomes stringy, and will again rapidly absorb moisture and swell. Spirits of wine does not cause the bladders to burst, and it renders the mucus slightly opaque. If a pinch of these achenia be dropped from a little height on damp paper, the greater number fall like shuttlecocks, upright and rest on the sole; the bladders then quickly burst, and as the paper dries the seeds become firmly attached to it. Many achenia, however, drop so as to rest on one edge of the sole, and in this case the drying of the mucus pulls the upper edge of the sole down, and so places the flower-like calyx nearly upright. Any one looking at a piece of paper over which when damp a number of achenia had been scattered by chance would conclude that each one had been placed upright and carefully gummed.

If an achenium falls upside down, so as to rest on the tips of the calyx, the sole does not touch the damp surface, yet moisture is so rapidly absorbed by the sepals, that in seven minutes I have seen the bladders burst: in this case as the paper dries the exuded mucus dries on the surface of the sole and the seed is not fixed; but if subsequently it be blown the right way up on a damp surface, the mucus will soften and act and attach it firmly. In so dry a climate as Australia the existence of these little bladders of dried mucus, having a strong affinity for water and becoming highly viscid on that side alone of the achenium which

1861. Fertilisation of British orchids by insect agency

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alights on the ground, seems a pretty adaptation to ensure the attachment of the seed to the first damp spot on which it may be blown. Whether the tendency of the achenia to place themselves upright be of any service to the plant would be hard to determine; but it seems possible that the salver-shaped calyx, which, as we have seen, so rapidly absorbs moisture and carries it down to the lower surface of the achenia, might aid in utilising dew or showers of fine rain. Charles Darwin.

1 2 3 4

James Drummond (1787–1863), Scottish botanist, superintendent of the government botanic gardens in Perth, Western Australia. See CCD8–9. Achene = ‘A small dry one-seeded fruit which does not open to liberate the seed.’ (OED) Pumilio argyrolepis is an orchid. Misprint of ‘attached’.

1861. Fertilisation of British orchids by insect agency. Gardeners’ Chronicle and Agricultural Gazette no. 6 (9 February): 122. F1706 I am much obliged to Mr. Marshall,1 of Ely, for his statement that the 15 plants of Fly Orchis (Ophrys muscifera) which does not grow in his neighbourhood, but which flourished in his garden, had not one of their pollen masses removed. The Orchis maculata, on the other hand, which likewise does not grow in the neighbourhood, had all its pollen masses removed. Mr. Marshall is not perhaps aware that different insects haunt different Orchids, and are necessary for their fertilisation.2 From the wide difference in shape of the flower of Orchis and Ophrys, I should have anticipated that they would be visited and fertilised [= pollinated] by different insects. In Listera, for instance, it is chiefly Ichneumonidæ, and sometimes flies, which by day perform the marriage ceremony. In the case of most Orchids it is nocturnal moths. Orchis pyramidalis, however, is visited by Zygæna, and I have examined one of these day-sphinxes with three pair of pollen-masses firmly attached to its proboscis. There can hardly be a doubt that the Butterfly Orchis is visited by different moths from most of the smaller Orchids; and I have recognised its peculiar pollen-masses attached to the sides of the face of certain moths. It is probable that the same kind of moths would visit all the species of true Orchis, which closely resemble each other in structure. Thus the Orchis conopsea, planted in a garden some miles from where any native plant grew, had its pollen-masses removed; so this is a parallel case with that of O. maculata given by Mr. Marshall. I have also transplanted the rare Malaxis to a place about two miles from its native bog, and it was immediately visited by some insect, and its pollen-masses were removed. On the other hand, the Epipactis latifolia, growing in my garden and flowering well, had not its pollen-masses removed; though in its own home, several miles distant, the flowers are regularly visited and thus fertilised. We thus see that the seeds of an Orchid might be carried by the wind to some distant place, and there germinate, but that the species would not be perpetuated unless the proper insects inhabited the site. I have now Goodyera repens growing in my garden, and I shall be curious to see next

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1861. Influence of the form of the brain on the character of fowls

summer whether our southern insects discover or appreciate the nectar of this Highland Orchid.3 C. Darwin.

1 2 3

William Marshall (1815–90), botanist and solicitor. CD refers to Marshall 1861 which was a response to Darwin 1860, F1706 (p. 300). See CCD9. See Orchids, pp. 36–8. See Orchids, pp. 112–16.

1861. Dun horses. The Field, the Farm, the Garden, the Country Gentleman’s Newspaper 17 (27 April): 358. F1960 I should esteem it a great favour if some of your numerous readers would take the trouble to give me any facts on the colour of the two parents of true dun horses. I mean by true duns, horses having a stripe or list along the spine, and often transverse stripes on the legs, the general colouring being either a mouse-dun or a tint which may be described as a creamy bay or chesnut. I am aware from inquires made in Norway, where true dun ponies are extremely common, that one or both parents are there always duns; and so it is, as I am informed, with the dun ponies of Devonshire. But I have occasionally seen dun cart-horses and hacks, which did not seem to have the blood of any pony or cob in them. It is surprising how often I have vainly asked the parentage of such horses, and vainly made inquiries from breeders. I have myself seen one colt, bred from a black mare and bay horse, which might certainly be called a dun, and which had a narrow, but strongly defined, spinal stripe before it shed its first hair. I should be much obliged for any information on this subject; and likewise whether a dun horse or pony is always dun-coloured before it sheds its first hair. Does the spinal stripe often disappear when the first coat is shed?—Charles Darwin (Down, Bromley, Kent.)1

1

CD was gathering information on striped and dun-coloured horses for Variation chapter 2. A reply appeared in the 18 May issue of The Field. See CCD9: 105.

1861. Influence of the form of the brain on the character of fowls. The Field, the Farm, the Garden, the Country Gentleman’s Newspaper 17 (4 May): 383. F1961 Sir,—From the recent investigations of Mr Tegetmeier,1 and from those of the older naturalists, most people who keep Polish fowls are aware that the tuft of feathers on their heads is supported by an extraordinary, almost hemispherical, protuberance of the front part of the skull. This protuberance is accompanied by an equal change in the shape of the brain. Pallas and some of the older writers describe the Polish fowl as, in consequence, stupid;2 but Mr Tegetmeier has shown that this is a mistake. The experience of many savage

1861. Phenomena in the cross-breeding of plants

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races of man proves that the external shape of the brain may be greatly modified by pressure, without the intellectual faculties being affected.3 Nevertheless, after having recently examined the skulls of Poland fowls, I am astonished that such profound changes should have produced no effect on the mental powers of these birds. Bechstein, writing in Germany in 1793, says, that although it is an error to suppose that fowls with such misformed skulls are stupid, yet that he had a white-crested black Poland which “was crazy, and which all day long wandered anxiously about.”4 I, also, formerly had a silverspangled Poland which was curiously affected; she sometimes seemed lost in reverie, and allowed any one to approach so as even to touch her; she was solitary in her habits, and was extraordinarily deficient in the sense of direction. I have seen her stray hardly more than a hundred yards from her feeding place, and become completely lost; and she would then continue obstinately to try to get through a fence in a direction exactly opposite to her home. Now, will any of your correspondents who have long kept tufted fowls have the kindness to state whether they have observed any clear signs of deficiency in the mental powers of any of their birds? or, has any one ever seen a “crazy fowl,” such as Bechstein describes, in any other breed?5 Charles Darwin. Down, Bromley, Kent.

1 2 3

4 5

William Bernhard Tegetmeier (1816–1912), journalist, naturalist, pigeon-fancier and poultry expert. He corresponded with CD 1855–81. Tegetmeier 1856. See CCD9: 117. Pallas 1767–80, pt. 4 (1767): 18–23. This remark suggests that CD also rejected phrenology, which dictated that the modification of the shape of the brain via the skull must result in altered character. However see Descent 1: 11. On phrenology see van Wyhe 2004. Johann Matthäus Bechstein (1757–1822), German forester, ornithologist and pedagogue. Bechstein [1789–95], 3: 400. An anonymous response, titled ‘Polish fowls’, appeared in the 11 May issue of The Field, p. 404: ‘I have half a dozen black, with white toppings, and they certainly are tame or stupid. You may tread upon them—they don’t seem to see well, and they seldom find the roosting-place, but crouch or perch anywhere.’

1861. Phenomena in the cross-breeding of plants. Journal of Horticulture and Cottage Gardener 1 (14 May): 112–13. F1713 (Having received the following letter from Mr. Darwin we forwarded it to Mr. Beaton,1 and now publish it with his reply. “Will Mr. Beaton, who has made such a multitude of most interesting observations on the propagation of plants, have the kindness to state whether varieties of the same species of Composite plants frequently cross each other by insect agency or other means? For instance, will any of the Cinerarias, if kept apart from other varieties, breed true? but if standing near other varieties, will they generally, or almost certainly, produce a much greater diversity of coloured seedlings?

308

1861. On dun horses, and on the effect of crossing differently coloured breeds

I saw an allusion by Mr. Beaton to this subject in The Cottage Gardener2 of last year with respect to Zinnias;3 and from this allusion I infer that Zinnia sports much when kept separate. As I am begging for information on the natural crossing of plants, I will likewise venture to inquire whether the great raisers of Hollyhocks find it necessary to keep each variety far separate from the others for raising seed. The late famous horticulturist, the Hon. and Rev. W. Herbert, when I visited him at Spofforth many years ago, remarked that he was much surprised (considering the structure of the flower and the relative periods of maturity of the pollen and stigma) how true some sorts of Hollyhocks bred, even when growing close to other varieties.4 I have found this to be the case with some of the varieties, and cannot understand how it is possible. Mr. Beaton might, if he pleased, write an article, very valuable to physiological botanists and of some practical utility, on the natural crossing of varieties. He might indicate in which genera crossing most commonly occurred, and in which it seldom or never occurred. For instance, I have observed Sweet Peas during several years and believe that they never cross; and it is not easy to make an artificial cross, though I succeeded at last, but got no good in a horticultural point of view.—Charles Darwin, Down, Bromley, Kent.”)5

1 2

3 4 5

Donald Beaton (1802–63), Scottish gardener who regularly contributed to the journal. See CCD9: 124–6. The Cottage Gardener changed its name from the issue of 2 April 1861 to the Journal of Horticulture, Cottage Gardener, and Country Gentleman. A journal of horticulture, rural and domestic economy, botany and natural history. It was edited by George William Johnson (1802–86) and Robert Hogg (1818–97). See Cottage Gardener, 10 April 1860, p. 19. William Herbert (1778–1847), naturalist, classical scholar and dean of Manchester from September 1845. See CD’s Journal, p. 24 and CCD2. Beaton’s lengthy response is available in DO. CD replied in Darwin 1861, F1714 (p. 309).

1861. On dun horses, and on the effect of crossing differently coloured breeds. The Field, the Farm, the Garden, the Country Gentleman’s Newspaper 17 (25 May): 451. F1962 I am very much obliged to Mr Bennett for his information about Norwegian dun ponies;1 but I received some years ago, through the Consul-General, Mr Crowe,2 the same account, which probably came from Mr Bennett. The point on which I am anxious for information is, whether a cross between two coloured horses (neither of which are dun) ever produce duns. I believe that we could thus obtain some insight into the aboriginal colour of the horse. I have as yet only a single case of the parentage of a dun—namely, a bay horse and black mare. A German writer (Hofacker) on the breeding of horses gives the case of two chesnuts producing a “goldfalb”, which, I believe, is a dun; and of a chesnut and brown producing a mouse-dun (mausrapp).3 I hope “Eques” will fulfil his kind offer of giving more information on the subject.4 I have collected a considerable body of evidence on the remarkable tendency of the offspring of a cross between differently-coloured breeds reverting to the colour of the aboriginal parent. With pigeons, I made numerous crosses for this express purpose, and frequently got a near approach to the marks and colour of the wild rock-pigeon.

1861. Cross-breeding in plants

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Again, I crossed a Spanish cock and white silk-hen; and one of the cockerels, although at first coal-black, in the autumn assumed the splendid red plumage of the wild jungle-cock (Gallus bankiva). Two young Cocks from the black Spanish and white game-hen assumed red neck and saddle hackles, so as partly to resemble a pile game cock. Mr Brent crossed two varieties of duck, and some of the ducklings assumed the plumage of the wild duck.5 I could give other facts. For instance, it is asserted in works on poultry that hens raised from a cross between two breeds of fowls neither of which sit, are good sitters; and here we see a cross has brought back the proper aboriginal instinct of incubation. In my own experience, however, the crossed offspring from the Spanish cock and a Poland hen did not incubate. If anyone has any analogous facts to those above given, and would communicate them, I should be much obliged. The whole subject of the results of crossing distinct breeds is an interesting one under many points of view.— Charles Darwin (Down, Bromley, Kent).

1 2 3 4 5

Bennett 1861. CD cited Bennett in Variation 1: 58. See CCD9: 139. John Rice Crowe (1792–1877), British consul-general in Norway, 1843–75. Hofacker 1828. ‘Eques’ 1861. ‘Eques (Argyllshire)’ responded with further details in the 8 June issue of The Field, pp. 494–5. Bernard Peirce Brent (1822–67), shipbuilder and pigeon breeder. CD acknowledged Brent’s assistance numerous times in Origin, Descent and Variation.

1861. Cross-breeding in plants. Fertilisation of Leschenaultia formosa. Journal of Horticulture and Cottage Gardener 1 (28 May): 151. F1714 Much obliged am I to Mr. Beaton for his very interesting answer to my question.1 When Mr. Beaton says he does “not know of an instance of the natural crossing of varieties,” I presume he intends to confine his remark to the plants of the flower garden; for every one knows how largely the varieties of the Cabbage cross, as is likewise the case (as I know from careful trial) with Radishes and Onions. It was this fact which led me to suppose that varieties of flower-garden plants would naturally cross. I can quite understand, after reading Mr. Beaton’s remarks, that it would be very difficult, perhaps impossible, to detect such natural crossing from the degree to which most of these varieties vary. I should, however, think that those who raise for sale seeds of distinct varieties of the Hollyhock, Stocks, &c., must know whether it is indispensable to keep the parent plants apart. I will not trouble Mr. Beaton again if he will have the kindness to procure for me answers on one or two points quoted in his paper (June 26, 1860) from the “king of British crossbreeders”—namely, whether I understand rightly that the white Anemone apennina seeding in a mass with the blue (Anemone apennina?) produced many pale shades? For this seems to be a case of two varieties naturally crossing, though I want to know the fact for another reason—namely, because Anemone does not secrete nectar; and secondly, whether Mathiola incana and glabra, which the writer speaks of as “crossing freely,” were artificially crossed.

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1861. Cross-breeding in plants

Mr. Beaton’s statement (July 24, 1860)2 that if the pollen of five kinds of Geranium (I presume what botanists call varieties, and not what are called species, are here referred to) are placed on the stigma of a flower, one kind alone takes the lead and produces an effect, seems to me a most curious observation. It is, I fear, unreasonable to ask for a few precise cases on this head; for, as I gather from Mr. Beaton, it must be difficult to know whether one or more kinds have produced an effect, owing to the great variability of crossed varieties. I have been delighted to observe how strongly Mr. Beaton insists that “not a flower in a thousand is fertilised by its own immediate pollen.”3 This is a subject which I have attended to for the last twenty years.4 From my experiments on a small scale I would not venture to put the case nearly as strongly as Mr. Beaton does; but on the other hand, some of the plants which Mr. Beaton advances as self-fertilisers seem, as far as I can trust my own observations, doubtful. I will give one instance, as it might possibly induce some one to try the experiment. Leschenaultia formosa5 has apparently the most effectual contrivance to prevent the stigma of one flower ever receiving a grain of pollen from another flower; for the pollen is shed in the early bud, and is there shut up round the stigma within a cup or indusium. But some observation led me to suspect that nevertheless insect agency here comes into play; for I found by holding a camel-hair pencil parallel to the pistil, and moving it as if it were a bee going to suck the nectar, the straggling hairs of the brush opened the lip of the indusium, entered it, stirred up the pollen, and brought out some grains. I did this to five flowers and marked them. These five flowers all set pods; whereas only two other pods set on the whole plant, though covered with innumerable flowers. The seeds in these pots were bad, or else I had not skill to make them germinate. I became so strongly convinced that insects would be found concerned in the fertilisation of these flowers, that I wrote to Mr. James Drummond,6 at Swan River in Australia, and asked him to watch the flowers of plants of this order; and he soon wrote to me that he had seen a bee cleverly opening the indusium and extracting pollen; and a bee with its mandibles thus covered with pollen would very likely effect a cross between one individual and another of the same species.7 I have been told that this pretty plant, the Leschenaultia formosa, never sets seed in this country. I wish some skilful cultivator would rout up the pollen within the indusium in the manner described, and see whether he could not thus get seeds.—Charles Darwin, Down, Bromley, Kent.8

1 2 3 4 5 6 7 8

Beaton 1861b. Beaton was responding to Darwin 1861, F1713 (p. 307). See CCD9: 129–32. Cottage Gardener, 26 June 1860, pp. 193–5. Beaton 1861b, p. 113. See Notebook E, pp. 144, 183, and Questions & experiments notebook, pp. 2, 14. (DO) Leschenaultia formosa = a species of Australian shrub. James Drummond (1763–1863), botanist of Swan River, Western Australia. See CCD8. CD published a letter on his own experiments ‘on the fertilisation of L. formosa and biloba’ in Darwin 1871, F1755 (p. 371).

1861. Fertilisation of Vincas

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1861. Dun horses. The Field, the Farm, the Garden, the Country Gentleman’s Newspaper 17 (15 June): 521. F1963 I hope that you will permit me to return my sincere thanks to “Eques,” of Argyllshire, for his information.1 I have talked to many persons, but have never found any one who knew nearly so much about the inheritance of colours in horses. “Eques” asks me to define what is meant by dun—I wish I could. It seems that almost any colour that is not bay, chesnut, black, grey, or one of the roans, is sometimes called dun. Even in mouse-duns I have seen two very distinct tints. The commonest colour which, in my limited experience, I have heard called dun, is a bay or chesnut, more or less diluted with cream or clay tint. In India, the Kattywar breed, which is more striped than any other breed, is called dun; but, as I am informed by Col. Poole, the colour is generally between brown and black.2 I now see that I should have put my question thus—Are horses, of any of the many indefinite tints commonly called duns, with a stripe along the spine, or with stripes across the legs, ever produced from parents neither of which are striped? for the first appearance or origin of the stripes is chiefly interesting for my purpose. I put the case—Are duns ever produced from parents neither of which are duns, because horses thus coloured are so frequently striped? and I thought I should more easily find out the parentage merely of the dun colour. What “Eques” says about the dirty mark on the withers, representing a single or double stripe, is exactly what I have observed. If “Eques” could find out, without much trouble, the colour of the dam and sire of his dun mare with the list and stripes, which was bred in Argyllshire, I should be very glad to hear it; but I have already caused “Eques” very much trouble, and I beg permission again to thank him.— Charles Darwin (Down, Bromley, Kent).3

1 2

3

‘Eques (Argyllshire)’ responded to CD’s query about horses in the 8 June issue of The Field pp. 494–5. See CCD9: 172. Skeffington Poole was a retired lieutenant-colonel from the first regiment light cavalry, Bengal. CD had written to him with queries about the colours and stripes of native Indian horses. See CCD7: 169. CD cited Poole in Variation 1: 58, 59. ‘Eques (Argyllshire)’ replied in the 27 July issue of The Field, p. 91, stating that the dam of his dun mare was a dun.

1861. Fertilisation of Vincas. Gardeners’ Chronicle and Agricultural Gazette no. 24 (15 June): 552. F1836 I do not know whether any exotic Vincas1 seed, or whether gardeners would wish them to seed, and so raise new varieties. Having never observed the large Periwinkle or Vinca major to produce seed, and having read that this never occurs in Germany, I was led to examine the flower. The pistil, as botanists know, is a curious object, consisting of a style, thickening upwards, with a horizontal wheel on the top; and this is surmounted by a beautiful brush of white filaments. The concave tire of the wheel is the stigmatic surface, as was very evident when pollen was placed on it, by the penetration of the pollen-tubes. The pollen is soon shed

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1861. Cause of the variation of flowers

out of the anthers, and lies embedded in little alcoves in the white filamentous brush above the stigma. Hence it was clear that the pollen could not get on to the stigma without the aid of insects, which, as far as I have observed in England, never visit this flower. Accordingly, I took a fine bristle to represent the proboscis of a moth, and passed it down between the anthers, near the sides of the corolla; for I found that the pollen sticks to the bristle and is carried down to the viscid stigmatic surface. I took the additional precaution of passing it down first between the anthers of one flower and then of another, so as to give the flowers the advantage of a cross; and I passed it down between several of the anthers in each case. I thus acted on six flowers on two plants growing in pots; the germens of these swelled, and on four out of the six I have now got fine pods, above 1½ inch in length, with the seeds externally visible; whereas the flower stalks of the many other flowers all shanked off. I wish any one who wishes to obtain seed of any other species that does not habitually seed would try this simple little experiment and report the result.2 I shall sow the seeds of my Vinca for the chance of a sport: for a plant which seeds so rarely might be expected to give way to some freak on so unusual and happy an occasion. Charles Darwin, Down, Bromley, Kent.

1 2

Periwinkle. Charles William Crocker (1832–68), foreman of the propagating department at the Royal Botanic Gardens, Kew, responded to this letter in Gardeners’ Chronicle, 27 July 1861, p. 699: Following the suggestion made by Mr. Darwin at page 552, a week or two ago, I thought that I would try if the tropical kinds of Vinca could be induced to produce seed, which is never the case under cultivation if left to themselves. I impregnated eight flowers, and in the course of a few days had the satisfaction of seeing that the pistils in seven cases were swelling well. The erect double follicles are now in several instances more than an inch long; in one they are not yet ripe. The plant upon which I tried the experiment was the white-flowered variety of Vinca rosea. I used the pollen from the same plant as I wished also to see if this variety would reproduce itself by seed, or if it will revert to the normal colour of the species. I merely passed a hair down the tube of one flower after another as an insect might insert its proboscis in its search for nectar. See CCD9: 172–3.

1861. Cause of the variation of flowers. Journal of Horticulture and Cottage Gardener 1 (18 June): 211. F1715 “D” of Deal,1 states, and, apparently, he is corroborated by Mr. Lightbody,2 that when Auriculas3 throw up side blooms these keep pretty true to their character; but that when they throw up a heart bloom—that is, from the axis of the plant, the flower, no matter what may be the colour of its edging, “is just as likely to come in any other class as in the one it belongs to.” This seems to be an extremely curious observation. It shows that some little light could be thrown on the laws of variation, if the many acute observers who read The Journal of Horticulture would contribute their knowledge on such points. I wish “D.” would have the kindness to give a few more details, such as out of so many heart blooms so many lost their character, and so many kept true; giving also the proportion in the side blooms which kept true.

1861. Cause of the variation of flowers

313

As I am appealed to, I will make a few observations on this subject; but I have no doubt others could throw more light on the question. Professor Moquin-Tandon asserts,4 that with irregular flowers, as Snapdragons, the terminal flower in the axis of the plant is more apt to become regular, or peloric as botanists say, than the other flowers. I once found a Laburnum tree with the terminal flower on each raceme nearly regular, having lost its peablossom structure. With many Pelargoniums (I have one at present in my greenhouse, but I know not its name), the central flower in each truss every year comes regular, loses the two dark patches of colour on the two upper petals, and, what is very curious, loses the nectary, which may be seen in all the other flowers cohering to the flower-stalk. In the common Carrot the central floret in the umbel is dark purple and very different from the others; and I find that this central little flower is extremely variable. Are there not other cases of species which habitually have the central flower different from the others? It must, however, be confessed, that Mr. Masters,5 a high authority on such subjects, disputes that peloric flowers are apt to be central; but it seems to me extremely improbable that the several recorded cases should be due to chance, and all these facts seem to hang together and to indicate that in the flower nearest the axis there is a tendency to differ from the others, or to be variable, or to revert to a hypothetical regular form—that is, as I should look at it, to revert to the structure of a remote ancestor. The curious case of the Auricula apparently falls into this same group of facts. I hope that some of your correspondents will state whether in the case of single buds sporting, as has so often occurred with Pelargoniums, it has been observed that such sports occur more frequently on one part of the plant than on another. I suppose it is not so, or it would have been noted. Having alluded to the central flower in certain Pelargoniums which have lost the two dark patches of colour and the nectary, I would venture to ask some skilful observer to try whether this flower could be made by artificial fertilisation and by pulling off some of the adjoining flowers to yield seed. The stigma should be fertilised with pollen from, if possible, a peloric flower on another plant; and access of other pollen should, of course, be prevented. Peloric flowers have generally been found quite sterile; but Willdenow6 got seeds from a peloric Snapdragon, and the peculiarity was inherited: hence it is possible, though not probable, that a new strain of quite symmetrically-flowered Pelargoniums might be thus raised. Experiments are tedious and very often fail; but it would be well worth while for any man endowed with plenty of patience to collect seed from the central floret and from the other florets on the same truss of any ordinary Pelargonium, and sow them separately and see which varied most. Of course, all the flowers should be fertilised by the same pollen and subsequently protected from insects. The same law which causes the heart bloom on an individual Auricula not to keep so true as a side bloom, might cause the seedlings of the central flower of a Pelargonium or other plant to vary more than the seedlings from the other and exterior flowers. This would be a secret worth discovering and revealing.—Charles Darwin, Down, Bromley, Kent.

1

D. of Deal 1861 queried: ‘How comes it to pass, that if an Auricula throws up a side bloom it is pretty sure to be in character; but that if it be from the heart of the flower … it is just as likely to come in any

314

2 3 4 5 6

1861. Effects of different kinds of pollen

other class as the one it belongs to? … Can Mr. Darwin, Mr. Beaton, or anybody enlighten me on the first of these points?’ See CCD9: 179–81. George Lightbody (d. 1872), gardener and member of the Falkirk Horticultural Society, Scotland, who raised numerous Auricula varieties. A type of primrose. Horace Bénédict Alfred Moquin-Tandon (1804–63), French botanist and naturalist. Moquin-Tandon 1841, p. 192. Maxwell Tylden Masters (1833–1907), botanist and physician; editor of the Gardeners’ Chronicle, 1865–1907. Karl Ludwig Willdenow (1765–1812), German botanist and pharmacist.

1861. Effects of different kinds of pollen. Journal of Horticulture and Cottage Gardener (9 July): 280–1. F1823 I Hope that you will grant me a little space to thank some of your correspondents and Mr. Beaton for his interesting information how to test the effects of different kinds of pollen on the divisions of the same stigma of a Pelargonium, for my special purpose of ascertaining whether one variety is prepotent over another.1 I fear that the Scarlet Pelargoniums include at least two wild forms, which botanists would rank as distinct species. If Mr. Beaton is at any time writing on these plants, perhaps he would tell us what he knows about the wild parent of the Horseshoe and other Scarlets. I am very glad that “P.” sent a list of his Pelargoniums with the central flower regular; for I was not aware how common the case was.2 Will “P.” be so obliging as to observe and report whether any of the regular central flowers set seed—that is, if the kinds specified are such as ever produce seed? With respect to the fertilisation of Wheat: several years ago I examined the flowers day by day, and came to the same conclusion as that which “H. C. K.” expresses so forcibly.3 Mr. Beaton apparently does not much venerate botanical authorities, but he might easily quote a long list of great names to show that Wheat is always fertilised in the bud; what has misled so many botanists I cannot imagine. But stranger assertions of the same kind may be met with: for instance, that cruciferous plants are generally fertilised before the flower opens! As I am away from home I write without my notes;4 but I remember that the Chinese have the singular belief that certain varieties of Wheat are always fertilised in the night-time. Col. Le Couteur, who attended so carefully to the varieties of Wheat, entertains no doubt that the different varieties, when growing near each other, cross.5 On the other hand, a full account has been published of a large number of varieties, I think 150, which were cultivated close together in some continental garden during several years, and never crossed each other.6 This account has much perplexed me; and I have sometimes been tempted to doubt whether any eye, however accurate, could have distinguished so many varieties, and that, perhaps, after all the |281| varieties did cross, Mr. Beaton might advance this case in support of his belief that Wheat is fertilised in the bud. As Mr. Beaton alludes to some mistake which he has made, might I venture to suggest to him to punish himself by telling sooner than he intended by what means he can produce from pollen of the same flower placed on the stigmas of the same variety two different sets of

1861. Orchids, Fertilization of

315

seedlings?7 That is a mystery which it is tantalising to wait for.—Charles Darwin, Down, Bromley, Kent.

1 2 3 4 5

6 7

Darwin 1861, F1715 (p. 312). See CCD9. P. 1861. ‘H. C. K.’ was Henry Cooper Key (1819–79), Rector of Stretton-Sugwas, Herefordshire. Key 1861. CD and his family were staying in Torquay, see Journal, p. 39. (DO) John Le Couteur (1794–1875), army officer, administrator and agricultural reformer in Jersey; founded the Royal Jersey Agricultural and Horticultural Society. His scientific contributions to the study of wheat led to a fellowship of the Royal Society in 1843, author of a well-known work on wheat, Le Couteur 1836. Loiseleur-Deslongchamps 1842–3, pp. 45, 70. CD referred to this in Variation 1: 314–15. Beaton 1861a challenged young gardeners to discover his technique for cross-breeding. See CCD9: 198.

1861. Parents of some gladioli. Journal of Horticulture and Cottage Gardener (10 September): 453. F1819 Really obliged should I be if you could tell me the names of the parents of Gladiolus gandavensis. Also, whether the six following varieties—Eldorado, Canasi, Ophir, Linné, Brenchleyensis, and Vulcain, are the progeny of G. gandavensis by itself, or of G. gandavensis crossed by some other species? If the history of these six varieties be not known, their appearance may, perhaps, to instructed eyes tell their probable origin.— Charles Darwin.1

1

The response following CD’s note, signed ‘D.B’ is omitted here. (DO) See CCD9: 257.

1861. Orchids, Fertilization of. Gardeners’ Chronicle and Agricultural Gazette no. 37 (14 September): 831. F1712 I have been endeavouring during several years to make out the many contrivances by which British Orchids are fertilised through insect agency. I am very anxious to examine a few exotic forms. Several gentlemen have kindly sent me specimens; but I have not seen one of Lindley’s grand division of Arethuseæ, which includes the Limodorideæ, Vanillideæ, &c.1 If any one would have the kindness to send me a few flowers and buds of any member of the group, packed in a small tin canister, by post, addressed as below, he would confer a very great favour on me. Would you have the kindness to inform me, if in your power, whether the late Professor Morren2 has published anything (and where) on the fertilisation of Orchids by insect agency? Charles Darwin, Down, Bromley, Kent.

316

1861. Is the female bombus fertilised in the air?

(We are unable to answer this question, and must refer it to others. After searching through Morren’s multitudes of pamphlets, we find nothing on Orchids except an academical dissertation on Orchis latifolia, and some remarks on the causes of the movements in the lips of Megaclinium.)

1 2

Lindley 1853. See CCD9: 260–1. Charles François Antoine Morren (1807–58), Belgian botanist and horticultural writer. CD cited Morren 1839 in Orchids, p. 270.

1861. Vincas. Gardeners’ Chronicle and Agricultural Gazette no. 37 (14 September): 831–2. F1716 A writer in your columns (p. 699) states that he caused Vinca rosea to seed at the Royal Gardens, Kew, by imitating the action of an insect in inserting its proboscis, as I had succeeded with the common Periwinkle.1 By implication it may be presumed |832| that V. rosea had not previously seeded at Kew. But another writer, “F. A. P.” (p. 736), states that his Vincas seed profusely.2 Mr. Horwood, gardener to G. H. Turnbull, Esq., of this place, has just been so kind as to bring me a small plant of Vinca rosea with nine flowers fertilised by the insertion of a horse-hair, and it now bears nine fine pods.3 Mr. Horwood says he has grown many plants for the last eight or nine years, and never before saw a pod. What can be the cause of the difference in the results obtained on the one hand by “F. A. P.”, and on the other by the writer from Kew and Mr. Horwood? Will “F. A. P.” have the kindness to state, if he sees this notice, whether his plants were in a greenhouse with the windows left open, so that the moths could get access at night?4 Charles Darwin, Down, Bromley, Kent.

1 2

3

4

[Crocker] 1861. See CCD9: 261–2. Gardeners’ Chronicle, 10 August 1861, p. 736: ‘I am surprised at “C. W. C.’s” assertion in your number for July 27, that “Tropical Vincas never produce seed under cultivation if left to themselves,” for I find both the white and pink kinds seed most profusely; in proof of this I enclose a small spray with seed pods on it. They sow themselves in the neighbouring pots, but the produce has never been different from the parent plants. F. A. P.’ John Horwood (1823–c. 1880), was also head gardener for Sir John Lubbock, 1862–3, and superintended the construction of CD’s hothouse, 1863. George Henry Turnbull (1819/20—c. 1870), builder, fruit grower and racehorse owner; resided at the Rookery in Downe. See CCD9: 261–2. No response has been found.

1861. Is the female bombus fertilised in the air? Journal of Horticulture and Cottage Gardener (22 October): 76. F1818 Would Col. Newman,1 who has so carefully attended to the habits of humble bees, have the kindness to state whether the queen humble bees are fertilised in the air or on the ground?

1862. [Recollections of Professor Henslow]

317

I have a special reason for wishing to know this little fact, and whether the fertilisation does not often take place as late as in September?—C. Darwin.

1

Henry Wenman Newman (1788–1865), army officer and landowner. The editors of the CCD9: 311 state ‘CD’s query was probably prompted by a note by Henry Wenman Newman published in the 15 October 1861 issue of the Journal of Horticulture (pp. 40–1), in which Newman questioned whether parthenogenesis occurred in bees and suggested that the eggs of the queen bee were fertilised by the ‘aura’ of the drone.’ Newman’s response followed CD’s letter: ‘The queens or females of the humble bees are not fertilised in the air, and the act of fertilisation takes place either in the nest or on some flower, or on the ground.’

1862. [Recollections of Professor Henslow]. In Jenyns, L., Memoir of the Rev. John Stevens Henslow M. A., F. L. S., F. G. S., F. C. P. S., late Rector of Hitcham and Professor of Botany in the University of Cambridge. London: John Van Voorst, pp. 51–5. F830 I went to Cambridge early in the year 1828, and soon became acquainted, through some of my brother entomologists, with Professor Henslow,1 for all who cared for any branch of natural history were equally encouraged by him. Nothing could be more simple, cordial, and unpretending than the encouragement which he afforded to all young naturalists. I soon became intimate with him, for he had a remarkable power of making the young feel completely at ease with him; though we were all awe-struck with the amount of his knowledge. Before I saw him, I heard one young man sum up his attainments by simply saying that he knew everything. When I reflect how immediately we felt at perfect ease with a man older and in every way so immensely our superior, I think it was as much owing to the transparent sincerity of his character, as to his kindness of heart; and, perhaps, even still more to a highly remarkable absence in him of all self-consciousness. One perceived at once that he never thought of his own varied knowledge or clear |52| intellect, but solely on the subject in hand. Another charm, which must have struck every one, was that his manner to old and distinguished persons and to the youngest student was exactly the same: to all he showed the same winning courtesy. He would receive with interest the most trifling observation in any branch of natural history; and however absurd a blunder one might make, he pointed it out so clearly and kindly, that one left him no way disheartened, but only determined to be more accurate the next time.2 In short, no man could be better formed to win the entire confidence of the young, and to encourage them in their pursuits. His Lectures on Botany were universally popular, and as clear as daylight.3 So popular were they, that several of the older members of the University attended successive courses. Once every week he kept open house in the evening, and all who cared for natural history attended these parties, which, by thus favouring intercommunication, did the same good in Cambridge, in a very pleasant manner, as the Scientific Societies do in London. At these parties many of the most distinguished members of the University occasionally attended; and when only a few were present, I have listened to the great men of those days, conversing

318

1862. [Recollections of Professor Henslow]

on all sorts of subjects, with the most varied and brilliant powers. This was no small advantage to some of the younger men, as it stimulated their mental activity and ambition. Two or three times in each session he took excursions with his botanical class; either a long walk to the habitat of some rare plant, or in a barge down the river to the fens, or in coaches |53| to some more distant place, as to Gamlingay,4 to see the wild lily of the valley, and to catch on the heath the rare natter-jack.5 These excursions have left a delightful impression on my mind. He was, on such occasions, in as good spirits as a boy, and laughed as heartily as a boy at the misadventures of those who chased the splendid swallow-tail butterflies across the broken and treacherous fens. He used to pause every now and then and lecture on some plant or other object; and something he could tell us on every insect, shell, or fossil collected, for he had attended to every branch of natural history. After our day’s work we used to dine at some inn or house, and most jovial we then were. I believe all who joined these excursions will agree with me that they have left an enduring impression of delight on our minds. As time passed on at Cambridge I became very intimate with Professor Henslow, and his kindness was unbounded; he continually asked me to his house, and allowed me to accompany him in his walks. He talked on all subjects, including his deep sense of religion, and was entirely open. I owe more than I can express to this excellent man. His kindness was steady: when Captain Fitzroy offered to give up part of his own cabin to any naturalist who would join the expedition in H.M.S. Beagle, Professor Henslow recommended me, as one who knew very little, but who, he thought, would work. I was strongly attached to natural history, and this attachment I owed, in large part, to him. During the five years’ voyage, he regularly corresponded with me and guided my efforts; he received, opened, and took care of all the specimens |54| sent home in many large boxes; but I firmly believe that, during these five years, it never once crossed his mind that he was acting towards me with unusual and generous kindness. During the years when I associated so much with Professor Henslow, I never once saw his temper even ruffled. He never took an ill-natured view of any one’s character, though very far from blind to the foibles of others. It always struck me that his mind could not be even touched by any paltry feeling of vanity, envy, or jealousy. With all this equability of temper and remarkable benevolence, there was no insipidity of character. A man must have been blind not to have perceived that beneath this placid exterior there was a vigorous and determined will. When principle came into play, no power on earth could have turned him one hair’s breadth.6 After the year 1842, when I left London, I saw Professor Henslow only at long intervals; but to the last, he continued in all respects the same man. I think he cared somewhat less about science, and more for his parishioners. When speaking of his allotments, his parish children, and plans of amusing and instructing them, he would always kindle up with interest and enjoyment. I remember one trifling fact which seemed to me highly characteristic of the man: in one of the bad years for the potato, I asked him how his crop had fared; but after a little talk I perceived that, in fact, he knew nothing about his own potatoes, but seemed to know exactly what sort of crop there was in the garden of almost every poor man in his parish. |55|

1862. Do bees vary in different parts of Great Britain

319

In intellect, as far as I could judge, accurate powers of observation, sound sense, and cautious judgment seemed predominant. Nothing seemed to give him so much enjoyment, as drawing conclusions from minute observations. But his admirable memoir on the geology of Anglesea,7 shows his capacity for extended observations and broad views. Reflecting over his character with gratitude and reverence, his moral attributes rise, as they should do in the highest character, in pre-eminence over his intellect. C. Darwin.

1

2

3 4 5 6 7

John Stevens Henslow, professor of botany at the University of Cambridge, died on 16 May 1861 aged sixty-five. Leonard Jenyns (1800–93), later Blomefield, naturalist, clergyman and Henslow’s brother-in-law. The Memoir was published in May 1862. See CCD9–10. See also CD’s reminiscences of Henslow in Autobiography, pp. 60, 64–9. In his Autobiography, p. 66, CD wrote: Whilst examining some pollen-grains on a damp surface I saw the tubes exserted, and instantly rushed off to communicate my surprising discovery to him. Now I do not suppose any other Professor of Botany could have helped laughing at my coming in such a hurry to make such a communication. But he agreed how interesting the phenomenon was, and explained its meaning, but made me clearly understand how well it was known; so I left him not in the least mortified, but well pleased at having discovered for myself so remarkable a fact, but determined not to be in such a hurry again to communicate my discoveries. See Sloan 1985, pp. 86 and 115 note 34, and Walters 1981, chapter 5. About 15 miles (24 km) WSW of Cambridge. Epidalea calamita, a toad which runs rather than hops. See Barlow 1967, p. 54. Henslow 1822.

1862. Do bees vary in different parts of Great Britain. Journal of Horticulture and Cottage Gardener (10 June): 207. F1716a I should feel much obliged if the “Devonshire Beekeeper” or any of your experienced correspondents would have the kindness to state whether there is any sensible difference between the bees kept in different parts of Great Britain. Several years ago an observant naturalist and clergyman, as well as a gardener, who kept bees, asserted positively that there were certain breeds of bees which were smaller than others, and differed in their tempers. The clergyman also said that the wild bees of certain forests in Nottinghamshire were smaller than the common tame bees. M. Godson,1 a learned French naturalist, also says that in the south of France the bees are larger than elsewhere, and that in comparing different stocks slight differences in the colour of their hairs may be detected. I have also seen it stated that the bees in Normandy are smaller than in other parts of France. I hope that some experienced observers who have seen the bees in different parts of Britain will state how far there is any truth in the foregoing remarks.2 In the Number of your Journal published May 15, 1860, Mr. Lowe3 gives a curious account of a new grey or light-coloured bee which he procured from a cottager. If this note should meet his eye I hope he will be so good as to report whether his new variety is still propagated by him.—Charles Darwin.

320

1862. Bees in Jamaica increase the size and substance of their cells

(We insert this without expressing any opinion, because we wish to have answers from as many of our readers as have paid attention to the subject. We, as well as the well-known writer of this inquiry, will be greatly obliged by any observations upon the subject. — Eds. of J. of H.)4

1 2 3 4

Misprint of ‘Godron’: Dominique Alexandre Godron (1807–80), French botanist, zoologist and ethnologist. Five responses to CD’s letter were published in the Journal of Horticulture. CD referred to the absence of distinct breeds of bees in Variation 1: 297–8. J. Lowe, a beekeeper in Edinburgh. Lowe 1860. Thomas White Woodbury, an editor of the bee section of the Journal of Horticulture, forwarded a slightly altered version of this letter to the Bienen Zeitung: Darwin 1862, F1718a. See CCD10: 238–9.

1862. Bees in Jamaica increase the size and substance of their cells. Journal of Horticulture and Cottage Gardener (15 July): 305. F1826 I am very much obliged to your several correspondents for their information in regard to the supposed differences in the bees of Britain.1 Possibly some few of your readers may be interested in the following case:—The hive bee was introduced many years ago into Jamaica. Having seen it stated that the cells were larger, I procured (through the kindness of Mr. R. Hill, of Spanish Town), some bees and comb.2 The bees have been carefully examined by Mr. F. Smith,3 of the British Museum, and pronounced to be the common species. I also secured the hind and front legs, the antennæ and jaws of worker bees from Jamaica and my own stock, and could detect no trace of difference in size or other character. But here comes the remarkable point—the diameter of the cells is conspicuously greater in about the proportion of 60 to 51 or 52 than in our English combs. The wax seems tougher, and the walls, I think, are thicker. The cells in parts of the comb were much elongated, and the whole hive contained a great quantity of honey. It certainly appears as if the instinct of the bee had become modified in relation to its new, hot, and rich home. But it seems to me an astonishing fact that the cells should have been made larger without a corresponding increase in the size of the body of the architect.—Charles Darwin, Down, Bromley, Kent.4 (The extra thickness and toughness of the wax employed by the bees in the torrid climate of Jamaica render the combs better capable of resisting the heat. The increased size of the brood-cells would better protect the larvae from the same excessive heat by interposing a wider air-filled space between them and the walls of the cells; for air is one of the worst conductors of heat. If such be the true explanations of the changes adopted by the bees, they are additional instances of instinct approaching closely to the confines of reason.—Eds.)

1 2

Darwin 1862, F1716a. (p. 319) See CCD10: 324–5. Richard Hill (1795–1872), Jamaican-born naturalist. See CCD7: 233, 322 and 401.

1862. Peas 3 4

321

Frederick Smith (1805–79), entomologist. See CCD10: 324–5 for a final paragraph written by CD which was not published.

1862. Bee-cells in Jamaica not larger than in England. Journal of Horticulture and Cottage Gardener (22 July): 323. F1824 I am sorry that you did not append the closing sentence to my communication about the Jamaica bees,1 as it would have shown your readers that I was doubtful on the subject. I have now to confess that I have made a gross blunder. The cells which I measured were drone-cells, as I am informed by the “Devonshire Bee-Keeper.” I could offer some explanation and apology to your readers for making so great a mistake; but it is a personal matter and would not interest them. How the statement in French works arose that the cells in West Indian combs are larger than those in European combs, I cannot conceive.—C. Darwin. (We certainly did not understand, nor do we think our readers understood, that Mr. Darwin stated the increased size of bee-cells in Jamaica as an established fact, and we made our comment hypothetically. We have seen combs from Jamaica since then, and the drone and worker cells are of the same sizes as in England. When Mr. Darwin wrote, he, probably, had not seen the cells of the workers.—Eds.)

1

Darwin 1862, F1826 (p. 320). For the omitted line see CCD10: 324–5.

1862. On the three remarkable sexual forms of Catasetum tridentatum, an orchid in the possession of the Linnean Society. [Read 3 April] Journal of the proceedings of the Linnean Society of London. Botany 6: 151–7. F17181

1

In this paper CD explained that the three radically different flowers produced by this orchid, which had led them to be classed in different genera, were three sexual forms male, female, and hermaphrodite. The paper was largely an extract of Orchids, pp. 236–8, a book which CD had been working on since mid-1861, and is therefore omitted here. See CCD10.

1862. Peas. Gardeners’ Chronicle and Agricultural Gazette no. 45 (8 November): 1052. F1719 Will any one learned in Peas have the kindness to tell me whether Knight’s Tall Blue and White Marrows were raised by Knight himself? If so, I presume that they are the offspring of the crosses described by him in the Philosophical Transactions for 1799.1 I find that the name “Knight” tacked to a Pea is not a guarantee that the sort was of his production. I will beg permission to ask one other question. Has any one who has saved seed Peas grown close to other kinds observed that the succeeding crop came up untrue or crossed?2 This certainly

322

1862. Cross-breeds of strawberries

occurs rarely if ever; yet from what I have observed on the manner of fructification of the Pea, I should have expected that such crossing would occasionally happen, as in the case of Dwarf Kidney Beans, of which fact I gave a striking example in your Paper of October 25, 1857.3 Charles Darwin, Down, Kent.

1 2 3

Knight 1799. See CCD10: 510–11. CD discussed Knight’s pea varieties in Variation 1: 326, 329–30, 2: 129. In fact 24 October, see Darwin 1857, F1697 (p. 267).

1862. On the two forms, or dimorphic condition, in the species of Primula, and on their remarkable sexual relations. [Read 21 November 1861] Journal of the Proceedings of the Linnean Society of London. Botany 6: 77–96. F17171

1

This article was published 1 March 1862; reprinted, with many alterations, in Forms of flowers (1877), pp. 14–30 and therefore omitted here. Walter Hood Fitch (1817–92), the botanical artist at the Royal Botanic Gardens, Kew, prepared the woodcuts. CD had fifty extra copies of the article printed to distribute privately. See the presentation list in CCD10, appendix III. Darwin wrote of this paper in his Autobiography pp. 128–9: I do not think anything in my scientific life has given me so much satisfaction as making out the meaning of the structure of these plants. I had noticed in 1838 or 1839 the dimorphism of Linum flavum, and had at first thought that it was merely a case of unmeaning variability. But on examining the common species of Primula, I found that the two forms were much too regular and constant to be thus viewed. I therefore became almost convinced that the common cowslip and primrose were on the high-road to become diœcious;—that the short pistil in the one form, and the short stamens in the other form were tending towards abortion. The plants were therefore subjected under this point of view to trial; but as soon as the flowers with short pistils fertilised with pollen from the short stamens, were found to yield more seeds than any other of the four possible unions, the abortion-theory was knocked on the head. After some additional experiment, it became evident that the two forms, though both were perfect hermaphrodites, bore almost the same relation to one another as do the two sexes of an ordinary animal. With Lythrum we have the still more wonderful case of three forms standing in a similar relation to one another. I afterwards found that the offspring from the union of two plants belonging to the same forms presented a close and curious analogy with hybrids from the union of two distinct species.

1862. Cross-breeds of strawberries. Journal of Horticulture and Cottage Gardener 3 (25 November): 672. F1720 Will any of your correspondents who have attended to the history of the Strawberry, kindly inform me whether any of the kinds now, or formerly, cultivated have been raised from a cross between any of the Woods or Alpines with the Scarlets, Pines, and Chilis? Also, whether any one has succeeded in getting any good from a cross between the Hautbois and any other kind? I am aware that Mr. Williams,1 of Pitmaston, succeeded in getting some sterile hybrids from the Hautbois and Woods; but whether these were ever at all largely propagated, I cannot find out. I am, also, aware that Mr. Knight and Mr. Williams raised many seedlings by crossing

1862. Variations effected by cultivation

323

Scarlets, Pines, and Chilis; but what I want to know is, whether any one has crossed these three latter kinds with the Wood or Alpine. I should feel greatly indebted to any one who would take the trouble to inform me on this head.2 —C. Darwin, Down, Bromley, Kent.

1 2

John Williams (1773–1853), Worcester nurseryman noted for his apple and pear varieties. His observations are given in Knight 1824, p. 294. CD cited this in Variation 1: 352. See CCD10: 559. Three replies appeared in the Journal of Horticulture: 9 December 1862, p. 721; 30 December 1862, p. 779; 20 January 1863, pp. 45–6.

1862. Variations effected by cultivation. Journal of Horticulture and Cottage Gardener 3 (2 December): 696. F1721 As you have been so obliging as to insert my query on the crossing of Strawberries,1 perhaps you will grant me the favour to insert two or three other questions, for the chance of some one having the kindness to answer them. I am writing a book on “Variation under Domestication,”2 in which I treat chiefly on animals; but I wish to give some few facts on the changes of cultivated plants. 1st. The fruit of the wild Gooseberry is said to weigh about 5 dwts.3 (I am surprised that it is so heavy), and from various records I find that towards the close of the last century the fruit had doubled in weight; in 1817, a weight of 26 dwts. 17 grs.4 was obtained; in 1825, 31 dwts. 13 grs.; in 1841, “Wonderful” weighed 32 dwts. 16 grs.; in 1845, “London” reached the astonishing weight of 36 dwts. 16 grs., or 880 grains. I find in the “Gooseberry Register” for 1862,5 that this famous kind attained only the weight of 29 dwts. 8 grs., and was beaten by “Antagonist.” Will any one have the kindness to inform me whether it is authentically known that the weight of 36 dwts. 16 grs., has, since the year 1845, been ever excelled? 2nd. Is any record kept of the diameter attained by the largest Pansies? I have read of one above 2 inches in diameter, which is a surprising size compared with the flowers of the wild Viola tricolor, and the allied species or varieties. 3rd. How early does any variety of the Dahlia flower? Mr. Salisbury, writing in 1808, shortly after the first introduction of this plant into England, speaks of their flowering from September, or the end of September, to November.6 Whereas, Mr. J. Wells, in Loudon’s “Gardener’s Magazine” for 1828, states that some of his dwarf kinds began flowering in June.7 I presume the end of June. Do any of the varieties now regularly flower as early as June? Have any varieties been observed to withstand frost better than other varieties?8 If any one will give me information on these small points, I shall feel greatly obliged.— Chas. Darwin, Down, Bromley, Kent.

1 2

Darwin 1862, F1720 (p. 322). See CCD10: 578–9. Variation.

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‘dwts.’ = penny (d) weights per ton. ‘A unit of weight equal to 24 grains (1/20 troy ounce), and formerly to 1/240 Tower pound, i.e. 22 1/2 grains, which was the actual weight of a silver penny.’ (OED) ‘grs.’ = grains. ‘The smallest English and U.S. unit of weight … now = 1/5760 of a lb. Troy, 1/7000 of a lb. avoirdupois.’ (OED) Gooseberry Grower ’s Register (1862): 192, 210. Richard Anthony Salisbury (1761–1829), botanist, later changed his name to Markham. The paper was read in 1808 and published as Salisbury 1812. Joseph Wells, the gardener of William Smith. Smith 1828, p. 179. CD refers to information provided on this question in Variation 1: 370.

1862. Penguin ducks. Journal of Horticulture and Cottage Gardener 3 (30 December): 797. F1825 If any of your readers have kept Penguin Ducks,1 and will have the kindness to observe one little point, and communicate the result, I should be greatly obliged. On examining the skeleton, I find that certain bones of the leg are longer than in the other breeds. I formerly kept these birds alive, and as far as I dare trust my memory, they could run considerably faster than other Ducks. Is this the case? It would, perhaps, be a good way to test their running powers to call the two kinds, when hungry, from a distance to their food, and see which arrived first.—Charles Darwin, Down, Bromley, Kent.

1

Indian Runner Duck, a breed of domestic duck with a striking upright posture, discussed in Variation 1: 281–6. See CCD10: 628–9.

1863. On the so-called “auditory-sac” of Cirripedes. By Charles Darwin, F.R.S. Natural History Review 3 (January): 115–6. F1722 In my work on Cirripedes1 I have described an orifice, previously unobserved, beneath the first pair of cirri, on each side of the body, including a very singular elastic sack, which I considered to be an acoustic organ. Furthermore I traced the oviduct from the peduncle to a mass of glands at the back of the mouth, and these glands I called ovarian.2 Dr. Krohn3 has recently stated that these glands are salivary, and that the oviduct runs down to the orifice, which I had thought to be the auditory meatus. It is not easy to imagine a greater mistake with respect to function than that made by me; but I expressly stated that I could never succeed in tracing the oviducts into actual union with these glands; nor the supposed nerve from the so-called acoustic sack to any ganglion. As Dr. Krohn is no doubt a much better dissector than I am, I fully admitted my error and still suppose that he is right. Nevertheless, several facts can hardly be reconciled with his view of the function of the several parts. To give one instance: if any one will look at the figure of the Anelasma (Lepadidæ, Pl. iv.),4 he will see how extremely difficult it is to understand by what means the ova coming out of the orifices (e) above referred to, could be arranged in the symmetrical lamellæ which

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extend up to the summit of the capitulum: it must be observed that the ova are united together by a delicate membrane enclosing each ovum; moreover the cirri in this animal are in atrophied condition, without regular articulations, so that it is inconceivable how the ova can be transported and arranged by their agency. I have lately received from an eminent naturalist, Prof. F. de Filippi, a paper (Estratto dell’ Arch. per la Zoolog. 31st Dec. 1861),5 chiefly devoted to the development of the ova of Cirripedes, in which the following passage occurs:— “The small size of Dichelaspis Darwinii has not enabled me to verify the relationship discovered by Krohn between this problematical organ and the termination of the oviduct; but on the other hand the transparency of the tissues has enabled me to perceive a peculiarity of structure which may help to elucidate the question. Fig. 13 represents what I persist in calling a hearing organ. Within a cavity, the walls of which are united to the surrounding tissues, there is a pear-formed sack or ampulla. On the neck of this ampulla, at a, are numerous minute lines parallel to each other and to the axis of the ampulla. I doubted at first whether the appearance of these lines arose from folds in the membrane, and therefore I separated some of the sacks, and I could then better convince myself that these lines correspond with true nervous fibres, thin and simple, embedded in the rather thick, resisting, and transparent substance which forms the walls of the ampulla. This circumstance seems to me to show clearly the sensitive nature of the organ, and hence to |116| favour Darwin’s opinion, who considers them to be organs of hearing.”

My object in asking you to publish this note, is to induce some one to attend to this curious organ; to endeavour to discover ova within the so-called auditory sack; for as each cirripede produces so many eggs, assuredly this might be effected without great difficulty. It is, however, possible (as I believe was suggested by Mr. R. Garner6 at the British Association, but whose paper I have mislaid,) that cirripedes, like certain Entomostraca, may lay two kinds of eggs; one set passing out through the problematical orifices; and another set coming out of the body in sheets, in the manner suggested by me;—namely, the ova collecting under the lining membrane of the sack before the act of exuviation, with a new membrane formed beneath them; so that the layer of eggs becomes external after the act of exuviation. If this view, to which I was led by many appearances, be correct, improbable as it may seem, it ought not to be difficult to find a specimen with the old membrane of the sack loose and ready to be moulted, with the new underlying membrane almost perfect, and with the layer of ova between them. Or a specimen might be found which had lately moulted, with its skin still soft, (and this I believe that I saw) with a layer of eggs still loosely attached to the new lining membrane of the sack.

1 2 3 4

Living Cirripedia 1: 53–5. See CCD10: 451–3. Living Cirripedia 1: 57–8. August David Krohn (1803–91), Russian-born zoologist, anatomist and embryologist working in Bonn. Krohn 1859 pointed out errors in CD’s interpretation of these anatomical features. Anelasma, plate iv from Living Cirripedia 1 (1851) by George Sowerby.

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Filippo De Filippi (1814–67), Italian zoologist, embryologist and geologist. The passage is translated from De Filippi 1861, p. 205. Robert Garner (1808–90), surgeon and naturalist who specialized in the anatomy of invertebrates and vertebrates. CD refers to Garner 1861. The paper makes no reference to the production of two kinds of eggs.

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1863. Influence of pollen on the appearance of seed. Journal of Horticulture and Cottage Gardener (27 January): 70. F1828 Few facts in vegetable physiology are more remarkable than the well-ascertained influence of the pollen of one species or variety on the seed and fruit of another species or variety whilst still attached to the female plant. There are several old accounts, and the case has been well proved by Gärtner of the colour of the pea in one variety of the Garden Pea, being changed by the direct action of the pollen of another differently-coloured variety.1 So, again, the famous St. Valery Apple tree produces many different kinds of fruit, according to the nature of the pollen used; for the singularly-constructed flowers yield no pollen, and they are annually fertilised by a party of French girls, who bring pollen from other trees, and mark with ribbons the flowers thus fertilised.2 About a year ago Mr. Beaton gave an analagous case, far more remarkable than any hitherto recorded, for he showed (if my memory does not deceive me) that the pollen of one species acted on the footstalk of the seed-capsule of another species, and caused it slowly to assume a position which it would not otherwise have acquired.3 I forget the name of the plant, and have vainly spent an hour in trying to find the passage, though I am sure I marked it. Will Mr. Beaton have the kindness to repeat the statement? and I am sure it is worth repetition. If he grant this favour, will he inform us whether his observations were made on several flowers, and during one or more years? I remember some difficulty in finding the name of the plant in such catalogues as I happened to have at hand, which led me to suppose that it had, like too many plants, more names than one.4—Charles Darwin.

1 2 3 4

Gärtner 1849, pp. 80–7. See CCD11: 90–1 and appendix V. See Variation 1: 350 and 401. Beaton 1860a. See Beaton’s responses in CCD11, appendix V.

1863. Vindication of Gärtner—effect of crossing peas. Journal of Horticulture and Cottage Gardener (3 February): 93. F1727a In my last communication1 I said that Gärtner had proved that the colour of the Pea in one variety of the garden Pea may be changed by the direct action of the pollen of another differently-coloured variety. Mr. Beaton authoritatively remarks on this: “Gärtner never found that—he only asserted it; and when he was pushed to the proof he lowered his sails, made a second edition of his great work, and confessed many of his errors.” He adds, “No cross-breeder of any practice in England at the present day would like to have his name associated with that of Gärtner for or against any exploit in crossing.”2 I should have taken no notice of this, although I should be sorry to lie under the imputation of having made an entirely incorrect statement, and although it is not pleasant to be flatly contradicted; but I wish much to be allowed to endeavour to vindicate the memory of one of the most laborious lovers of truth who ever lived. It is painful to see a long life of honest labour repaid by contumely from a fellow-experimentalist, who, I suppose—anyhow

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I hope—never read one page of the great original work—namely, the “Bastarderzeugung,” published in 1849, a mine of wealth to all who will explore it. Gärtner, when young, and at the very commencement of his long work, committed a very foolish action; he crossed a number of plants belonging to distinct genera without having taken due precaution to exclude insects, and when he found their capsules full of seed, he thought that he had succeeded in crossing them. With the enthusiasm of a beginner he most unwisely published3 the result, and to this first paper Dr. Herbert4 has alluded with proper blame. When Gärtner found his seedlings came up pure, he, like an honest and excellent man (as all who knew anything of his life will admit that he was), publicly confessed his error.5 Gärtner’s great and last work, entitled “Versuche über die Bastarderzeugung,” contains in 790 closely-printed pages the detailed results of nine thousand distinct experiments in crossing, together with admirable observations on the whole subject of hybridisation. This is a greater number of experiments than, as I believe, have ever been published by any other man, even by Kölreuter,6 and a far greater number than those published by Dr. Herbert. One great superiority in Gärtner’s work over those of Kölreuter, Herbert, and others consists in his having actually taken the trouble to count the seeds in the capsules of every cross and hybrid which he made. He kept an exact record at the time of making each experiment; and this I have reason to believe was not done by Herbert, and certainly has been very far from the case with other English experimentalists. I cannot resist here mentioning—as some who honour, as I do, the memory of Dr. Herbert, might like to hear the fact—that I have reason to believe that the last words ever uttered by Herbert were on his favourite subject of crossing. I called on him in London, and saw that he was very feeble.7 I wished to leave him, but he stopped me, and talked with much interest on this subject. An hour or two afterwards, as far as I could judge by the published account, he was found dead in the chair in which I left him. But to return to the Pea-question. An account of the various crosses made by Gärtner (he selected the most constant varieties) between differently coloured Peas, with the results given in detail, will be found at page 81 to 85 in his “Bastarderzeugung.” Gärtner was led to try these experiments from doubting the accuracy of Wiegmann’s statements,8 and he found many of them incorrect; but he was compelled to believe in the Pea case; not that Peas can be crossed with Vetches, to which other statement of Wiegmann Mr. Beaton alludes. I may add that Gärtner knew of the account, published in vol. v., pages 234, 237 of the “Transactions of the Horticultural Society of London,” on the influence of pollen on Peas.9 In an old volume of the “Philosophical Transactions,” vol. xliii., page 525, there is a full account, with every appearance of truth, of Peas in adjoining rows affecting each other.10 The Rev. M. J. Berkeley has, as I have been informed, subsequently to the publication of Gärtner’s book, tried again the Pea-experiment with the same result.—Charles Darwin, Down, Bromley, Kent.

1 2 3

Darwin 1863, F1828 (p. 327). See CCD11: 109–12. Beaton 1863, p. 70. Gärtner 1826.

1863. Fertilisation of orchids 4 5 6 7 8 9 10

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William Herbert. Gärtner 1827, pp. 74–5. Joseph Gottlieb Kölreuter (1733–1806), German botanist. Kölreuter 1761–6. CD visited Herbert’s house in Hereford Street, Park Lane, London, on 28 May 1847, see CCD4: 44. Wiegmann 1828. Goss 1822. Cooke 1745, p. 526 note by Cromwell Mortimer. See CCD11: 112 note 15.

1863. On the existence of two forms, and on their reciprocal sexual relation, in several species of the genus Linum. [Read 5 February] Journal of the Proceedings of the Linnean Society. Botany 7: 69–83. F17231

1

The genus includes Linseed or Flax. A modified version of this article was reprinted in Forms of flowers, pp. 81–101, and is therefore omitted here. See CCD10. Extracts from this paper, with commentary by Asa Gray, were published in the American Journal of Science and Arts (September 1863): 279–84, see CCD11.

1863. Fertilisation of orchids. Journal of Horticulture and Cottage Gardener (31 March): 237. F1724a Had Mr. Anderson1 asked me two days ago for any facts illustrative of his case of unopened flowers of Cattleya crispa and Dendrobium cretaceum producing seed-capsules, I could have given no sort of information; nor can I now explain the fact. By an odd coincidence, yesterday I received a very interesting letter from Dr. Hermann Cruger,2 the Director of the Botanic Garden at Trinidad, who informs me that certain native species, and native species alone, of Cattleya, Epidendrum, and Schomburghkia, “are hardly ever known to open their flowers, but which nearly always set fruit.” In answer to Dr. Cruger, I have asked him to look at the seed or send me some, and inform me whether it appears good. Will Mr. Anderson have the kindness to send me a few seeds produced by his unopened flowers? I further asked Dr. Cruger whether these Orchids in their native haunts never open their flowers. I can hardly believe that this can be the case, seeing how manifestly adapted the structure of their organs of fructification is to the action of insects. But it is known that several plants, such as Violets, Campanulas, Oxalis, &c., produce two kinds of flowers: one sort adapted for self-fertilisation, [= self-pollination] and the other sort for fertilisation by insect agency or other means. In some cases the two kinds of flowers differ very little in structure; and it occurs to me as possible that something of this kind may occur with Orchids. Dr. Cruger further informs me that with certain Orchids, as in those which do not open their flowers, the pollen-masses after a time become pulpy; and though remaining still in situ, emit their pollen-tubes, which reach the stigma, and thus cause fertilisation.

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An excellent observer, Mr. J. Scott,3 of the Royal Botanic Gardens of Edinburgh, will, I am sure, permit me to state that he has been making similar observations, and has seen the pollen-tubes emitted from the pollen-masses whilst still in their proper positions. These facts were all unknown to me when I published my small work on the Fertilisation of Orchids; but I ought, perhaps, to have anticipated their occurrence, for I saw the pollentubes emitted from the pollen within the anthers in the Bird’s-nest Orchid, and likewise in monstrous flowers of the Man Orchis. This latter fact seems related to Mr. Anderson’s remark, that flowers of an imperfect character, wanting a petal or sepal, had a great tendency to produce seed-capsules.4 These curious observations by Dr. Cruger, Mr. Anderson, and Mr. Scott, convince me that I have in my work underrated the power of tropical Orchids occasionally to produce seed without the aid of insects; but I am not shaken in my belief that their structure is mainly related to insect agency. With most British Orchids this conclusion may be looked on as established. I will only add that since the publication of my work, a number of persons have set seed-capsules with various tropical Orchids. Charles Darwin, Down, Bromley, Kent.

1 2 3 4

James Anderson (1831/2–99), Scottish gardener and orchid specialist. Anderson 1863. Hermann Crüger (1818–64), German pharmacist and botanist. See CCD11. John Scott (1836–80), Scottish botanist. Anderson 1863, p. 207.

[Darwin, C. R.] 1863. [Review of] Contributions to an insect fauna of the Amazon Valley. By Henry Walter Bates, Esq. Transact. Linnean Soc. vol. XXIII. 1862, p. 495. Natural History Review 3 (April): 219–24. F1725 The author reveals some curious facts in this memoir,1 which from its unpretending and somewhat indefinite title we fear may be overlooked in the ever-flowing rush of scientific literature. The main subject discussed is the extraordinary mimetic resemblance which certain butterflies present to other butterflies belonging to distinct groups. To appreciate the degree of dissimulation practised by these insects, it is necessary to study the beautiful plates with which the memoir is adorned. In a district where, for instance, an Ithomia abounds in gaudy swarms, another butterfly, namely a Leptalis, will often be found mingled in the same flock, so like the Ithomia in every |220| shade and stripe of colour and even in the shape of its wings, that Mr. Bates, with his eyes sharpened by collecting during eleven years, was, “though always on my guard,” continually deceived. When the mockers and the mocked are caught and compared they are found to be totally different in essential structure, and to belong not only to distinct genera, but often to distinct families. If this mimicry had occurred in only one or two instances, it might have been passed over as a strange coincidence. But travel a hundred miles, more or less, from a district where one Leptalis

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imitates one Ithomia, and a distinct mocker and mocked, equally close in their resemblance, will be found. Coloured drawings of seven mocking forms of Leptalis, and six mocked forms of Ithomia, and one of another genus are given. Altogether no less than ten genera are enumerated, which include species that imitate other butterflies. The mockers and mocked always inhabit the same region; we never find an imitator living remote from the form which it counterfeits. The mockers are almost invariably rare insects; the mocked in almost every case abound in swarms. In the same district in which a species of Leptalis closely imitates an Ithomia, there are sometimes other Lepidoptera mimicking the same Ithomia; so that in the same place, species of three genera may be found all closely resembling a species of a fourth genus. It is highly remarkable that even moths, notwithstanding their dissimilarity in structure and general habits of life, sometimes so closely imitate butterflies (these butterflies being simultaneously mocked by others) that, as Mr. Bates says, when “seen on the wing in their native woods, they deceive the most experienced eye.” These several facts and relations carry the strongest conviction to the mind that there must be some intimate bond between the mocking and mocked butterflies. It may, however, be naturally asked, why is the one considered as the mocked form; and why are the others, or two or three other butterflies which inhabit the same district in scanty numbers, considered as the mockers? Mr. Bates satisfactorily answers this question, by showing that the form which is imitated keeps the usual dress of the group to which it belongs, whilst the counterfeiters have changed their dress and do not resemble their nearest allies. In these facts, of which only a brief abstract has been given, we have the most striking case ever recorded of what naturalists call analogical resemblance. By this term naturalists mean the resemblance in shape, for instance, of a whale to a fish—of certain snake-like Batrachians to true snakes—of the little burrowing and social pachydermatous Hyrax to the rabbit, and other such cases. We can understand resemblances, such as these, by the adaptation of different animals to similar habits of life. But it is scarcely possible to extend this view to the variously coloured stripes and spots on butterflies; more especially as these are known often to differ greatly in the two sexes. Why then, we are naturally eager to know, has one butterfly or moth so often assumed the dress of another quite distinct form; why to the perplexity of naturalists has Nature condescended |221| to the tricks of the stage? We remember only one statement, made by Mr. Andrew Murray in his excellent paper on the Disguises of Nature,2 namely that insects thus imitating each other usually inhabit the same country, which combined with the fact of the imitators being rare and the imitated common, might have given a clue to the problem. Mr. Bates has given to these facts the requisite touch of genius, and has, we cannot doubt, hit on the final cause of all this mimicry. The mocked and common forms must habitually escape, to a large extent, destruction, otherwise they could not exist in such swarms; and Mr. Bates never saw them preyed on by birds and certain large insects which attack other butterflies; he suspects that this immunity is owing to a peculiar and offensive odour that they emit. The mocking forms, on the other hand, which inhabit the same district, are comparatively rare, and belong to rare groups; hence they must suffer habitually from some danger, for from the number of eggs laid by all butterflies, without doubt they would, if not persecuted, in three or four generations swarm over the

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whole country. Now if a member of one of these persecuted and rare groups were to assume a dress so like that of a well-protected species that it continually deceived the practised eyes of an ardent entomologist, it would often deceive predacious birds and insects, and thus escape entire annihilation. This we fully believe is the true explanation of all this mockery. Mr. Bates truly observes, that the cases of one butterfly mocking another living butterfly do not essentially differ from the innumerable instances of insects imitating the bark of trees, lichens, sticks, and green leaves. Even with mammals, the hare on her form can hardly be distinguished from the surrounding withered herbage. But no case is known of a deer or antelope so like a tiger as to deceive a hunter; yet we hear from Mr. Bates of insects more dissimilar than a ruminant and carnivore, namely, of a cricket most closely resembling a cicindela—a veritable tiger amongst insects. Amongst birds, all that habitually squat on the ground in open and unprotected districts, resemble the ground, and never have gaudy plumage. It appears, however, that two cases of birds mocking other birds have been observed by that philosophical naturalist, Mr. Wallace. Amongst insects, on the other hand, in all parts of the world, there are innumerable cases of imitation; Mr. Waterhouse has noted an excellent instance (and we have seen the specimens) of a rare beetle inhabiting the Philippine Archipelago, which most closely imitates a very common kind belonging to a quite distinct group. The much greater frequency of mockery with insects than with other animals, is probably the consequence of their small size; insects cannot defend themselves, excepting indeed the kinds that sting, and we have never heard of an instance of these mocking other insects, though they are mocked: insects cannot escape by flight from the larger animals; hence they are reduced, like most weak creatures, to trickery and dissimulation. |222| By what means, it may be asked, have so many butterflies of the Amazonian region acquired their deceptive dress? Most naturalists will answer that they were thus clothed from the hour of their creation—an answer which will generally be so far triumphant that it can be met only by long-drawn arguments; but it is made at the expence of putting an effectual bar to all further inquiry. In this particular case, moreover, the creationist will meet with special difficulties; for many of the mimicking forms of Leptalis can be shown by a graduated series to be merely varieties of one species; other mimickers are undoubtedly distinct species or even distinct genera. So again, some of the mimicked forms can be shown to be merely varieties; but the greater number must be ranked as distinct species. Hence the creationist will have to admit that some of these forms have become imitators, by means of the laws of variation, whilst others he must look at as separately created under their present guise; he will further have to admit that some have been created in imitation of forms not themselves created as we now see them, but due to the laws of variation! Prof. Agassiz, indeed, would think nothing of this difficulty; for he believes that not only each species and each variety, but that groups of individuals, though identically the same, when inhabiting distinct countries, have been all separately created in due proportional numbers to the wants of each land. Not many naturalists will be content thus to believe that varieties and individuals have been turned out all ready made, almost as a manufacturer turns out toys according to the temporary demand of the market.

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There are some naturalists, who, giving up to a greater or less extent the belief of the immutability of species, will say that as the mocked and mocking forms inhabit the same district, they must have been exposed to the same physical conditions, and owe to this circumstance their common dress. What direct effect the physical conditions of life, that is, climate with all its contingencies and the nature of the food, produce on organic beings is one of the most abstruse problems in natural history, and cannot be here discussed. But we may remark that when a moth closely resembles a butterfly, or better still, when a cricket resembles a Cicindela, it becomes very difficult to believe that insects so widely dissimilar in their internal structure and habits of life, should have had their external organization alone so largely influenced by their conditions of life as to become almost identical in appearance. Can we believe that one insect comes to resemble the bark of a tree; another a green leaf; another in its larval condition the dead twig of a branch; or that a quail or snipe comes to resemble the bare ground on which it lies concealed, through the direct action of the physical conditions of life? If in these cases, we reject this conclusion, we ought to reject it in the case of the insects which mock other insects. Assuredly something further is required to satisfy our minds: what this something is, Mr. Bates explains with singular clearness |223| and force. He shows that some of the forms of Leptalis, whether these be ranked as species or varieties, which mimick so many other butterflies, vary much. In one district several varieties (which are figured) occur; one alone of these pretty closely resembles the common Ithomia of the same district. In a few other cases, this Leptalis presents two or three varieties, one of which is much commoner than the others, and this alone mocks an Ithomia. In several cases a single Leptalis, which sometimes must be ranked, according to the usual rules followed by naturalists, as a variety and sometimes as a distinct species, mocks the common Ithomia of the district. From such facts as these, Mr. Bates concludes that in every case the Leptalis originally varied; and that when a variety arose which happened to resemble any common butterfly inhabiting the same district (whether or no that butterfly be a variety or a so-called distinct species) then that this one variety of the Leptalis had from its resemblance to a flourishing and little persecuted kind a better chance of escaping destruction from predacious birds and insects, and was consequently oftener preserved;—“the less perfect degrees of resemblance being generation after generation eliminated, and only the others left to propagate their kind.” This is Natural Selection. Mr. Bates extends this view, supporting it by many facts and forcible arguments, to all the many wonderful cases of mimickry described by him. He adds, “thus, although we are unable to watch the process of formation of a new race as it occurs in time, we can see it, as it were, at one glance, by tracing the changes a species is simultaneously undergoing in different parts of the area of its distribution.” To the naturalist who is interested with respect to the origin of species, the most important parts of this Memoir, together with the descriptive portion at the end, are probably those which treat on the limits of species, on sexual variation, on the variation of important characters, such as the neuration3 of the wings, &c. We cannot here discuss these points. Mr. Bates shows that there is a perfect gradation in variability, from butterflies, of which hardly two can be found alike, to slight varieties, to well-marked races, to races which can

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hardly be distinguished from species, to true and good species. Under this point of view, the history of Mechanitis polymnia well deserves study: after describing its several varieties, Mr. Bates adds, “these facts seem to teach us that, in this and similar cases, a new species originates in a local variety, formed in a certain area, where the conditions are more favourable to it than to the typical form, and that a large number of such are simultaneously in process of formation from one variable and widely distributed species.” It is hardly an exaggeration to say, that whilst reading and reflecting on the various facts given in this Memoir, we feel to be as near witnesses, as we can ever hope to be, of the creation of a new species on this earth. We will only notice briefly one other point which has an important bearing on the production of new races and species; namely the |224| statement repeatedly made that in certain cases the individuals of the same variety evince a strong predilection to pair together. We do not wish to dispute this statement; it has been affirmed by credible authors, that two herds of differently coloured deer long preserved themselves distinct in the New Forest; and analogous statements have been made with respect to races of sheep in certain Scotch islands; and we know no reason why the same may not hold good with varieties in a state of nature. But we are by our profession as critics bound to be sceptical, and we think that Mr. Bates ought to have given far more copious evidence. He ought also to have given in every case his reasons in full for believing that the closely allied and co-existing forms, with which his varieties do not pair, are not distinct species. Naturalists should always bear in mind such cases as those of our own willow wrens, two of which are so closely alike that experienced ornithologists can with difficulty distinguish them, excepting by the materials of which their nests are built; yet these are certainly as distinct species as any in the world. We think so highly of the powers of observation and reasoning shown in this Memoir, that we rejoice to see by the advertisements that Mr. Bates will soon publish an account of his adventures and his observations in natural history, during his long sojourn in the magnificent valley of the Amazon. We believe that this work will be full of interest to every admirer of Nature.4

1 2 3 4

Henry Walter Bates (1825–92), traveller, naturalist and entomologist. Assistant secretary, Royal Geographical Society of London, 1864–92. Bates 1861. See CCD11. Andrew Murray (1812–78), lawyer, entomologist and botanist, assistant secretary to the Royal Horticultural Society, 1860–65. Murray 1860. The arrangement and number of veins. Bates 1863.

1863. The doctrine of heterogeny and modification of species. Athenæum no. 1852 (25 April): 554–5. F1729 Down, Bromley, Kent, April 18. I hope that you will permit me to add a few remarks on Heterogeny, as the old doctrine of spontaneous generation is now called, to those given by Dr. Carpenter,1 who, however, is

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probably better fitted to discuss the question than any other man in England. Your reviewer2 believes that certain lowly organized animals have been generated spontaneously—that is, without pre-existing parents—during each geological period in slimy ooze. A mass of mud with matter decaying and undergoing complex chemical changes is a fine hiding-place for obscurity of ideas. But let us face the problem boldly. He who believes that organic beings have been produced during each geological period from dead matter must believe that the first being thus arose. There must have been a time when inorganic elements alone existed on our planet: let any assumptions be made, such as that the reeking atmosphere was charged with carbonic acid, nitrogenized compounds, phosphorus, &c. Now is there a fact, or a shadow of a fact, supporting the belief that these elements, without the presence of any organic compounds, and acted on only by known forces, could produce a living creature? At present it is to us a result absolutely inconceivable. Your reviewer sneers with justice at my use of the “Pentateuchal terms,” “of one primordial form into which life was first breathed”:3 in a purely scientific work I ought perhaps not to have used such terms; but they well serve to confess that our ignorance is as profound on the origin of life as on the origin of force or matter. Your reviewer thinks that the weakness of my theory is demonstrated because existing Foraminifera4 are identical with those which lived at a very remote epoch. Most naturalists look at this fact as the simple result of descent by ordinary reproduction; in no way different, as Dr. Carpenter remarks, except in the line of descent being longer, from that of the many shells common to the middle Tertiary and existing periods. The view given by me on the origin or derivation of species, whatever its weaknesses may be, connects (as has been candidly admitted by some of its opponents, such as Pictet, Bronn, &c.)5 by an intelligible thread of reasoning a multitude of facts: such as the formation of domestic races by man’s selection,—the classification and affinities of all organic beings,— the innumerable gradations in structure and instincts,—the similarity of pattern in the hand, wing or paddle of animals of the same great class,—the existence of organs become rudimentary by disuse,—the similarity of an embryonic reptile, bird and mammal, with the retention of traces of an apparatus fitted for aquatic respiration; the retention in the young calf of incisor teeth in the upper jaw, &c.,—the distribution of animals and plants, and their mutual affinities within the same region,—their general geological succession, and the close relationship of the fossils in closely consecutive formations and within the same country; extinct marsupials having preceded living marsupials in Australia, and armadillo-like animals having preceded and generated armadilloes in South America,—and many other phenomena, such as the gradual extinction of old forms and their gradual replacement by new forms better fitted for their new conditions in the struggle for life. When the advocate of Heterogeny can thus connect large classes of facts, and not until then, he will have respectful and patient listeners. Dr. Carpenter seems to think that the fact of Foraminifera not having advanced in organization from an extremely remote epoch to the present day is a strong objection to the views maintained by me. But this objection is grounded on the belief—the prevalence of which seems due to the well-known doctrine of Lamarck6—that there is some necessary law of advancement, against which view I have often protested. Animals may even become

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degraded, if their simplified structure remains well fitted for their habits of life, as we see in certain parasitic crustaceans. I have attempted to show (‘Origin,’ 3rd edit. p. 135)7 that lowly-organized animals are best fitted for humble places in the economy of nature; that an infusorial animalcule or an intestinal worm, for instance, would not be benefited by acquiring a highly complex structure. Therefore, it does not seem to me an objection of any force that certain groups of animals, such as the Foraminifera, have not advanced in organization. Why certain whole classes, or certain numbers of a class, have advanced and others have not, we cannot even conjecture. But as we do not know under what forms or how life originated in this world, it would be rash to assert that even such lowly endowed animals as the Foraminifera, with their beautiful shells as figured by Dr. Carpenter, have not in any degree advanced in organization. So little do we know of the conditions of life all around |555| us, that we cannot say why one native weed or insect swarms in numbers, and another closely allied weed or insect is rare. Is it then possible that we should understand why one group of beings has risen in the scale of life during the long lapse of time, and another group has remained stationary? Sir C. Lyell, who has given so excellent a discussion on species in his great work on the ‘Antiquity of Man,’ has advanced a somewhat analogous objection, namely, that the mammals, such as seals or bats, which alone have been enabled to reach oceanic islands, have not been developed into various terrestrial forms, fitted to fill the unoccupied places in their new island-homes; but Sir Charles has partly answered his own objection.8 Certainly I never anticipated that I should have had to encounter objections on the score that organic beings have not undergone a greater amount of change than that stamped in plain letters on almost every line of their structure. I cannot here resist expressing my satisfaction that Sir Charles Lyell, to whom I have for so many years looked up as my master in geology, has said (2nd edit. p. 469):—“Yet we ought by no means to undervalue the importance of the step which will have been made, should it hereafter become the generally received opinion of men of science (as I fully expect it will) that the past changes of the organic world have been brought about by the subordinate agency of such causes as Variation and Natural Selection.”9 The whole subject of the gradual modification of species is only now opening out. There surely is a grand future for Natural History. Even the vital force may hereafter come within the grasp of modern science, its correlations with other forces have already been ably indicated by Dr. Carpenter in the Philosophical Transactions;10 but the nature of life will not be seized on by assuming that Foraminifera are periodically generated from slime or ooze. Charles Darwin.

1

2 3

Carpenter 1863 was a response to Richard Owen’s anonymous review (Owen 1863) of Carpenter 1862. See CCD11: xviii–xix, 324–6 and appendix VII for more detail on this episode and the Athenæum letters by Owen and Carpenter. Richard Owen, see note 1 above. Origin, p. 484, which was changed in the 2d ed., p. 484, to: ‘into which life was first breathed by the Creator’. This phrase was omitted from the 3d (p. 519) and subsequent editions (Peckham ed. 1959, p. 753) and DO.

1863. Origin of species 4 5

6 7

8 9 10

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Single-celled protists whose shells can be preserved as fossils. François Jules Pictet de la Rive (1809–72), Swiss zoologist and palaeontologist. CD refers to his review of Origin, Pictet de la Rive 1860. Heinrich Georg Bronn (1800–62), German palaeontologist who translated and superintended the first German ed. of Origin (1860), to which CD refers. Lamarck 1809 and 1815–22. Origin, 3rd ed. p. 135 reads: ‘On my theory the present existence of lowly organised productions offers no difficulty; for natural selection includes no necessary and universal law of advancement or development—it only takes advantage of such variations as arise and are beneficial to each creature under its complex relations of life. And it may be asked what advantage, as far as we can see, would it be to an infusorian animalcule—to an intestinal worm—or even to an earth-worm, to be highly organised? If it were no advantage, these forms would be left by natural selection unimproved or but little improved; and might remain for indefinite ages in their present little advanced condition.’ Lyell 1863a, pp. 443–8. Lyell 1863b, p. 469. Carpenter 1850.

1863. Origin of species. Athenæum no. 1854 (9 May): 617. F1730 Down, Bromley, Kent, May 5. I hope that you will grant me space to own that your Reviewer1 is quite correct when he states that any theory of descent will connect, “by an intelligible thread of reasoning,” the several generalizations before specified. I ought to have made this admission expressly; with the reservation, however, that, as far as I can judge, no theory so well explains or connects these several generalizations (more especially the formation of domestic races in comparison with natural species, the principles of classification, embryonic resemblance, &c.) as the theory, or hypothesis, or guess, if the Reviewer so likes to call it, of Natural Selection. Nor has any other satisfactory explanation been ever offered of the almost perfect adaptation of all organic beings to each other, and to their physical conditions of life. Whether the naturalist believes in the views given by Lamarck, or Geoffroy St.-Hilaire,2 by the author of the ‘Vestiges,’3 by Mr. Wallace and myself,4 or in any other such view, signifies extremely little in comparison with the admission that species have descended from other species and have not been created immutable; for he who admits this as a great truth has a wide field opened to him for further inquiry. I believe, however, from what I see of the progress of opinion on the Continent, and in this country, that the theory of Natural Selection will ultimately be adopted, with, no doubt, many subordinate modifications and improvements. Charles Darwin.

1 2 3 4

[Owen 1863] which criticized CD’s letter to the Athenæum, Darwin 1863, F1729 (p. 334). Etienne Geoffroy Saint-Hilaire (1772–1844), French zoologist and professor of zoology, Muséum d’Histoire Naturelle, 1793. [Chambers] 1844. CD discussed these earlier transmutation theorists in the historical sketch added to the 3d and later editions of Origin.

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1863. Appearance of a plant in a singular place

1863. [Letter on yellow rain]. Gardeners’ Chronicle and Agricultural Gazette no. 28 (18 July): 675. F1727 A very slight shower, lasting hardly more than a minute, fell here this morning (July 2) about 10 o’clock.1 My wife gathering some flowers immediately afterwards noticed that the drops of water appeared yellowish, and that the white Roses were all spotted and stained. I did not hear of this circumstance till the evening; I then looked at several Roses and Syringas and found them much stained in spots. Between the petals of the double white Roses there were still drops of the dirty water: and this when put under the microscope showed numerous brown spherical bodies, 1/1000 of an inch in diameter, and covered with short, conical transparent spines. There were other smaller, smooth, colourless sacs about 4/7000 of an inch in diameter. I preserved a minute drop of the water beneath thin glass, cementing the edges, and next morning looked rather more carefully at it. I then observed that the water swarmed with elongated, moving atoms, only just visible with a quarter-inch object glass. Whether these inhabited the rain-drops, when they fell, I cannot of course say; but I suspect so, for the petals, now that they are nearly dry, seem stained with absolutely impalpable matter of the colour of rust of iron. This matter has chiefly collected, in the act of drying, on the edges of each spot. The Rev. M. J. Berkeley could tell us what the larger spherical bodies are which fell this day by myriads from the sky, carried up there, I presume, by some distant whirlwind.

1

CD was writing from his home, Down House, Kent. See CCD11: 515.

1863. Appearance of a plant in a singular place. Gardeners’ Chronicle and Agricultural Gazette no. 33 (15 August): 773. F1727b In a hard gravel walk close to my house, my gardener1 and myself distinctly remember, about five or six years ago, two little rosettes of purplish leaves pushing their way up. We neither of us could imagine what they were; they were soon trampled down and apparently killed. But this spring they have re-appeared in exactly the same spot, and were protected. They have now flowered and prove to be Epipactis latifolia. This Orchid, though by no means a rare plant, I have never seen in this neighbourhood, and have heard only once of its having been found in a wood about a mile and a half distant. The gravel walk was made 20 years ago; and before that time the spot existed as a littleused carriage drive; and about 25 or 26 years ago it was a pasture field. How could this Epipactis, which is so rare a plant here, have come to this spot? The root stock seems to have lain dormant under the gravel for the last five or six years. Could a seed have been blown here from a distance and have germinated during some season when the walk was neglected? The tall stems growing up in the midst of the bare gravel surface present an odd appearance, and the case seems to me a singular one.2 Charles Darwin, Down, Bromley, Kent.

1863. Vermin and traps

1 2

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Henry Lettington (b. 1823, still living in Downe in 1901). See CCD11: 592–3. CD published further remarks on these orchids in Darwin 1869, F1748, p. 150 (p. 360) and Orchids 2d ed., pp. 101–2.

1863. Vermin and traps. Gardeners’ Chronicle and Agricultural Gazette no. 35 (29 August): 821–2. F1728 It is a common observation that cases of brutality to horses, asses, and other large quadrupeds, are much less frequently witnessed now than they were some time ago. This is no doubt owing to the general increase of humanity, and to these animals being now under the protection of the law. An English gentleman would not himself give a moment’s unnecessary pain to any living creature, and would instinctively exert himself to put an end to any suffering before his eyes; yet it is a fact that every game preserver in this country sanctions a system which consigns thousands of animals to acute agony, probably of eight or ten hours duration, before it is ended by death. I allude to the setting of steel traps for catching vermin. The iron teeth shut together with so strong a spring, that a pencil which I inserted was cracked and deeply indented by the violence of the blow. The grip must be close enough not to allow of the escape of a small animal, such as a stoat or a magpie; and therefore when a cat or a rabbit is caught, the limb is cut to the bone and crushed. A humane game-keeper said to me, “I know what they must feel, as I have had my finger caught.” The smaller animals are often so fortunate as to be killed at once. If we attempt to realise the sufferings of a cat, or other animal when caught, we must fancy what it would be to have a limb crushed during a whole long night, between the iron teeth of a trap, and with the agony increased by constant attempts to escape. Few men could endure to watch for five minutes, an animal struggling in a trap with a crushed and torn limb; yet on all the well-preserved estates throughout the kingdom, animals thus linger every night; and where game keepers are not humane, |822| or have grown callous to the suffering constantly passing under their eyes, they have been known by an eyewitness to leave the traps unvisited for 24 or even 36 hours. Such neglect as this is no doubt rare; but traps are often forgotten; and there are few game keepers who will leave their beds on a cold winter’s morning, one hour earlier, to put an end to the pain of an animal which is safely in their power. I subjoin the account of the appearance of a rabbit caught in a trap, given by a gentleman, who, last summer witnessed the painful sight many times. “I know of no sight more sorrowful than that of these unoffending animals as they are seen in the torture grip of these traps. They sit drawn up into a little heap, as if collecting all their force of endurance to support the agony; some sit in a half torpid state induced by intense suffering. Most young ones are found dead after some hours of it, but others as you approach, start up, struggle violently to escape, and shriek pitiably, from terror and the pangs occasioned by their struggles.” We naturally feel more compassion for a timid and harmless animal, such as a rabbit, than for vermin, but the actual agony must be the same in all cases. It is scarcely possible to exaggerate the suffering thus endured from fear, from acute pain,

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maddened by thirst, and by vain attempts to escape. Bull baiting and cock fighting have rightly been put down by law; I hope it may never be said that the members of the British Parliament will not make laws to protect animals if such laws should in any way interfere with their own sports. Some who reflect upon this subject for the first time will wonder how such cruelty can have been permitted to continue in these days of civilisation; and no doubt if men of education saw with their own eyes what takes place under their sanction, the system would have been put an end to long ago. We shall be told that setting steel traps is the only way to preserve game, but we cannot believe that Englishmen when their attention is once drawn to the case, will let even this motive weigh against so fearful an amount of cruelty. The writer of these remarks will be grateful for any suggestions, addressed to A. B., Mr. Strong,1 Printer, Bromley, Kent. C.D.2

1 2

Edward Strong (b. 1809), printer and stationer on the High Street, Bromley, Kent. The text of this article, together with a woodcut illustration, was privately printed as ‘An Appeal’ in [E. Darwin and C. Darwin 1863]. See CCD11, appendix IX where the Appeal is reprinted and explained in a detailed introduction. The woodcut is reproduced here.

1863. Lettre de M. Darwin à M. de Quatrefages. [Read 16 July] Bulletins de la Société d’Anthropologie de Paris 4: 378–9. F18371 Ce nâta est pour vous, un cas excellent car la race est bien établie et doit tirer son origine de l’Amérique du Sud. C’est une race très-singulière. Une courte description de la tête a été faite par le professeur Owen dans le Catalogue descriptif de la collection ostéologique du collége des chirurgiens, 1853 page 624.2 Vous y verrez que la connexion des os est modifiée, car le maxillaire ne s’unit pas aux os du nez. En examinant un grand nombre de squelettes de lapins, de canards, de poulets et de pigeons, j’ai rencontré plusieurs modifications remarquables dans les squelettes; mais comme elles ne sont pas encore publiées, vous ne pourriez en tirer aucun parti.3 Le pigeon Powter (grosse-gorge ou boulans) descendant certainement du Columba Livia, est un cas intéressant car il a l’œsophage très-amplifié at modifié.4

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Dans le premier chapitre de mon Origine de l’Espèce, vous trouverez un extrait des modifications remarquables chez les pigeons.5 Les poulets à crête, ou, comme nous les appelons, polish |379| fowls, sont un excellent cas;6 ils produisent parfaitement bien; autrefois, il n’y avait qu’un sexe dont le crâne fût affecté, maintenant les deux sexes sont affectés. J’insère ici une gravure sur bois très-bien faite.7 J’ai examiné beaucoup de crânes. Il y a un changement étonnant de forme dans le cerveau lui-même, et dans l’intérieur du crâne, en outre du changement des os extérieurs. English translation:8 This nãta is an excellent case for you because the race is well established and must derive its origin from South America. It is a very singular race. A short description of the head was made by Professor Owen in the Descriptive catalogue of the osteological collection of the College of Surgeons, 1853 page 624.9 You will see there that the connection of the bones is modified, since the maxillary is not fused to the bones of the nose. In examining a great number of skeletons of rabbits, ducks, poultry, and pigeons, I have observed several remarkable modifications in the skeletons, but since these are not yet published, they would not be of any use to you.10 The Powter pigeon (inflated gullet or boulans) which undoubtedly descends from Columba Livia, is an interesting case since it has a very enlarged and modified oesophagus.11 In the first chapter of my Origin of species you will find a section about remarkable modifications in pigeons.12 The crested fowls, or, as we call them, polish fowls are an excellent case;13 they reproduce perfectly well; in the past there was only one sex in which the skull was affected; now both sexes are affected. I am enclosing a very well drawn woodcut.14 I have examined a great many skulls. There is an astonishing change of form in the brain itself and in the interior of the skull, besides the change in the external bones.

1

2 3 4 5 6 7 8 9 10 11 12 13 14

Jean Louis Armand de Quatrefages de Bréau (1810–92), French zoologist, anthropologist and professor of the natural history of man, Muséum d’Histoire Naturelle. See CCD11: 313–14, 708–9. [Owen] 1853, 2: 3832. See also Variation 1: 89–91. See Variation 1: 103–304. See Variation 1: 137–9 for an engraving and description. Origin, pp. 20–8. See Variation 1: 227–30. See Variation 1: 229. Translation reproduced with permission from CCD11: 708–9. [Owen] 1853, 2: 3832. See also Variation 1: 89–91. See Variation 1: 103–304. See Variation 1: 137–9 for an engraving and description. Origin, pp. 20–8. See Variation 1: 227–30. Fig. 32 from Variation 1: 229.

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1863. On the thickness of the Pampean formation, near Buenos Ayres

1863. On the thickness of the Pampean formation, near Buenos Ayres. By Charles Darwin, Esq., M.A., F.R.S., F.G.S., &c. [Read 3 December 1862] Quarterly Journal of the Geological Society of London 19 (1 February): 68–71. F17241 M. Sourdeaux2 and J. Coghlan,3 Esq., C.E., have had the kindness to send me, through E. B. Webb,4 Esq., C.E., some excellent sections of, and specimens from, two artesian wells lately made at Buenos Ayres. I beg permission to present these specimens to the Geological Society, as they would be of considerable service to any one investigating the geology of that country. The Pampean formation is in several respects so interesting, from containing an extraordinary number of the remains of various extinct Mammifers, such as Megatherium, Mylodon, Mastodon, Toxodon, &c., and from its great extent, stretching in

1863. On the thickness of the Pampean formation, near Buenos Ayres

Thickness at Barracas. Feet. a. b. c. d. e. f. g. h. k1.

Clays and Tosca........................................ Sand....................................................... Very sandy clay........................................ Dark-blue plastic clay................................ Tosca with calcareous nodules Yellow sands, very fine and fluid................. Green sands............................................. Tertiary clay and sandstone (for details see fig. 2) Hard sandstone at the bottom of the Barracas Well....................................................... k2. Very calcareous red clay, becoming more marly beneath; bored through to a depth of............

343

Thickness at Buenos Ayres. Feet.

... 13 } 47

......... 57 ......... 51 ......... 52

94 66 34 4½

......... 45 ......... 62 ......... 33

...

......... 225

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1863. On the thickness of the Pampean formation, near Buenos Ayres

a north and south line for at least 750 geographical miles, and covering an area fully equal to that of France, that, as it appears to me, a record ought to be preserved of these borings. Southward, at the Rio Colorado, the Pampean formation meets the great Tertiary formation of Patagonia; and northward, at Sta. Fé Bajada, it overlies this same formation with its several extinct shells. In the central region near Buenos Ayres no natural section shows its thickness; but, by the borings there made in two artesian wells (figs. 1 & 2), the Pampean mud, with Tosca-rock,5 is seen to extend |69| downwards from the level of the Rio Plata to a depth of 61 feet, and to this must be added 55 feet above the level of the river. These argillaceous beds overlie coarse sand, containing the Azara labiata (a shell characteristic of the Pampean formation), and attaining a thickness of about 93 feet.* So that the entire thickness |70| of the great estuarine or Pampean formation near Buenos Ayres is nearly 210 feet.

*

The following extract from the Report of the borers relates to this bed:—“The bed of yellow, fluid sands between 18m .60 and 47m .20 below the ground contains a subterranean ascending current, the level of which has not varied by a centimetre for three years. The level is 0m.60 (2 feet over the level of the wells at Barracas). This bed (‘napa’) is powerfully absorbent. At 68m.30 a second subterranean current (‘overflowing’) was met, which rose one foot over the surface of the ground at Barracas. The discharge was about 50 pipes daily, but the water was salt and undrinkable. At 73m.30 was found a third subterranean current (‘overflowing’), which reached with difficulty the level of the ground. The discharge might be calculated at 100 pipes daily. The water was very salt, and absorbed that of the first overflowing current. The great spring was met with at 77m.65.” As regards the quality and abundance of the water, Mr. Coghlan remarks that “The quantity of water discharged per hour through a tube of about 4¼ inches in diameter, at a level of 6 feet above high-water mark, was 2658 gallons. Its temperature was 21° Cent., and it had a slightly disagreeable taste, from its being impregnated with salts of lime and magnesia and a small quantity of sulphuretted hydrogen.”

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This formation rests on various marine beds of indurated green clay, sand with corals, sandstone, and limestone, altogether 107 feet in thickness. These beds contain fragments of the great Ostrea Patagonica, O. Alvarezii (?), Pecten Paranensis, and other shells, apparently the same (but they have not been rigorously compared) with those enumerated by M. A. d’Orbigny and by myself as found at Sta. Fé Bajada, as well as at various points on the coast of Patagonia. The already enormous continuous extension of the Patagonian Tertiary formation is thus largely increased. Beneath these beds a mass of red calcareous clay, becoming in the lower part more and more marly, containing layers of sand, and of the thickness of 213 feet, was bored through to a depth of 470 feet from the level of |71| the Rio Plata. This lower mass contained no fossils, and its age is of course unknown;* but, I may add, that I saw at two points in Western Banda Oriental, beneath the marine tertiary strata, beds of red clay with marly concretions, which, from their mineralogical resemblance to the overlying Pampean formation, seemed to indicate that at an ancient period the Rio Plata had deposited an estuarine formation, subsequently covered by the marine tertiary beds, and these by the more modern estuarine formation, with its remains of numerous gigantic mammalia; and that, finally, the whole had been elevated into the present plains of the Pampas.

1 2 3 4 5

This was reprinted in Geological Observations 2d ed., pp. 363–7. Adolfo Sourdeaux, engineer who bored artesian wells in Buenos Aires. John Coghlan (1824–90), government engineer and member of the Board of Public Works in Buenos Aires. Edward Brainerd Webb (1820–79), civil engineer working in London. A reddish or brown, soft, marly (i.e. lime-rich), argillaceous (i.e. with significant amounts of clay minerals) rock, which occurs over vast areas of the Pampas. See Geological observations 2d ed., p. 315. In DAR33: 249 (DO) CD noted ‘The name probably originates in the term ‘tierra tosca’ or ‘coarse earth’. [Gordon Chancellor].

1864. On the sexual relations of the three forms of Lythrum salicaria. [Read 16 June] Journal of the Linnean Society of London. Botany 8: 169–96. F17311

1

*

Lythrum salicaria = Purple loosestrife. Edited portions of this article appeared in Forms of flowers, pp. 137–67 and it is therefore omitted here. CD also discussed Lythrum salicaria in Origin 4th ed., p. 323 and Variation 2: 166, 183. See CCD12.

It was supposed by Dr. Burmeister to be Silurian. [Karl Hermann Konrad Burmeister (1807–92), German zoologist, geologist and Director of the Museo Nacional in Buenos Aires, 1861–80.]

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1864. Letter to the Council of the Royal Horticultural Society

1864. Ancient gardening. Gardeners’ Chronicle and Agricultural Gazette no. 41 (8 October): 965. F1732 I should be very much obliged if any one who possesses a treatise on gardening or even an Almanac one or two centuries old would have the kindness to look what date is given as the proper period for sowing Scarlet Runners or dwarf French Beans. I am anxious to ascertain, as far as is possible, whether these plants can now be sown at all earlier than was formerly the case. The title, date, and place of publication of any old treatise should be given. Charles Darwin, Down, Bromley, Kent.1

1

CD received several replies, see CCD12: 361–2. In Variation 2: 314, CD remarked ‘I have not been able, by searching old horticultural works, to answer this question satisfactorily.’

1864. [Letter to the Council of the Royal Horticultural Society on the prizes recently offered by the Society]. Proceedings of the Royal Horticultural Society 4: 91–3. F1910 Cambridge, April 11, 1864. Gentlemen,—We beg respectfully to represent to the Council of the Royal Horticultural Society that serious injury will be caused to the native plants of England by the prizes recently offered by the Society for collections of wild specimens of English plants.1 But, at the same time, we desire to thank the Society for having shown a wish to promote a knowledge of scientific Botany. The value of land, and the advanced state of agriculture consequent therefrom, has caused many wild plants to be now confined to few or even to single localities, often of small extent. It is feared that such species will be extirpated by collectors for prize herbaria, who are desirous of obtaining every plant known to grow in their county, and are greatly tempted to destroy what they do not gather, in order to prevent other candidates from finding as many species. The plants liable to be thus destroyed are mostly not such as gardeners would wish to obtain for cultivation: they possess no beauty nor interest to the common eye, but are of much value in the estimation of scientific botanists. There is scarcely a county in England in which one or more plants will not be in danger of extirpation by the collectors for these prizes. Neither will the prizes promote scientific botany amongst the class for whose benefit they are intended, |92| for there is nothing to ensure the recipient of a prize himself knowing the names or localities of the plants in his collection, or that he has examined a single botanical book, gathered any of the specimens, or even seen any of them. But supposing the case not to be so bad as this, the objection will probably apply, in some degree, to every collection sent to the Society; for no attempt is made (indeed it would be next to impossible) to ensure the collection being really formed, named, mounted and arranged by the candidate himself, without the help of other persons.

1865. Testimonials in favour of Mr. Adam White

347

As it seems nearly certain that these prizes cannot be of much use in promoting scientific Botany, and must seriously threaten the rare, curious, and botanically interesting plants with extirpation, we venture to express our hope that the Council may be induced to withdraw them before the season has arrived for the destruction to commence.—We have the honour to be Gentlemen, your most obedient servants,2 C. Darwin, M.A., F.R.S. [The remaining 126 signatures are omitted.]

1 2

See Proceedings of the Royal Horticultural Society 4 (1864): 2, 17, and CCD12: 131–3. As a result of the objections to the prize competition the Royal Horticultural Society issued revised instructions to account for the concerns expressed in this and other letters. See CCD12: 132 note 5.

1865. On the movements and habits of climbing plants. [Read 2 February] Journal of the Linnean Society of London. Botany 9: 1–118. F17331

1

The paper was published on 12 June 1865 in a double issue of the Journal of the Linnean Society. Botany. Two offprints were produced, one commercial the other for the author, see Freeman 1977, pp. 116–18. This article was later enlarged and published as Climbing plants (1875) and therefore omitted here. Darwin wrote of the paper in his Autobiography p. 129: The writing of this paper cost me four months: but I was so unwell when I received the proofsheets that I was forced to leave them very badly and often obscurely expressed. The paper was little noticed, but when in 1875 it was corrected and published as a separate book it sold well. I was led to take up this subject by reading a short paper by Asa Gray, published in 1858, on the movements of the tendrils of a Cucurbitacean plant. He sent me seeds, and on raising some plants I was so much fascinated and perplexed by the revolving movements of the tendrils and stems, which movements are really very simple, though appearing at first very complex, that I procured various other kinds of Climbing Plants, and studied the whole subject. I was all the more attracted to it, from not being at all satisfied with the explanation which Henslow gave us in his Lectures, about Twining plants, namely, that they had a natural tendency to grow up in a spire. This explanation proved quite erroneous. Some of the adaptations displayed by climbing plants are as beautiful as those by Orchids for ensuring cross-fertilisation.

1865. Testimonials in favour of Mr. Adam White, during twenty-five years Assistant in the Zoology Department, British Museum; corresponding member of the Linnean Society of Lyons, of the Stettin Entomological Society etc. Edinburgh: Thomas Constable, p. 10. F345b Down, Kent, 26th December 1851. My Dear Sir,—I have much pleasure in expressing my high opinion of your Zoological attainments; and your great zeal for every branch of Natural History must strike all who are acquainted with you.

1866. Partial change of sex in unisexual flowers

348

Your papers in the scientific journals show how successfully you have worked out original materials. I have often had occasion to visit the working department in the British Museum, and I have invariably found you, permit me to add, most zealous and obliging in your endeavours to aid me in every possible way, and in giving me all the information in your power. You are at full liberty to show this letter to any one; and I beg to remain, my dear Sir, Yours sincerely, Charles Darwin. Adam White, Esq.

1

1

Adam White (1817–79), Scottish assistant in the Zoology Department of the British Museum, 1835–63, who specialised in entomology and Crustacea. He described some of CD’s arachnids from the Beagle voyage in White 1841. In 1909 zoologist and entomologist Roland Trimen (1840–1916) recalled that in 1859 ‘I was at work in the next compartment to that in which Adam White sat, and heard someone come in and a cheery mellow voice say ‘Good-morning Mr. White; —I am afraid you won’t speak to me any more’ … ‘Ah, Sir! if ye had only stopped with the Voyage of the Beagle!’’ Poulton 1909, p. 214. This letter was first printed in Testimonials of Adam White, F.L.S., Assistant in the Zoological Department, British Museum [1854], p. 15, as part of an application for the chair of natural history at Edinburgh University in 1854. Edward Forbes was appointed before the pamphlet was distributed. In 1865 White had the testimonials printed again in order to gain employment in Edinburgh after retiring from the British Museum due to mental illness. See CCD5: 76.

1865–6. Note on Medicago lupulina. In Henslow, G., Note on the structure of Medicago sativa, as apparently affording facilities for the intercrossing of distinct flowers. [Read 16 November] Journal of the Linnean Society of London. Botany 9: 328. F1809 I covered a number of plants with a net (which I know does not injure their seeding), and left others close by uncovered, and these were visited incessantly by bees. I could not compare their relative fertility with accuracy, on account of the easy shedding of the seed; but I gathered 150 not quite ripe pods of both; those from under the net weighed 77 grains, and those visited by the bees weighed 101 grains. No doubt the difference in the weight of the seed would have been considerably greater, as the pod is formed independently of the number of seeds.1

1

Medicago lupulina = Black Medic. CD’s observations were later published in Cross and self fertilisation, p. 368. See CCD13: 292.

1866. Partial change of sex in unisexual flowers. Gardeners’ Chronicle and Agricultural Gazette no. 6 (10 February): 127. F1735 Will any of your botanical readers have the kindness to inform me, whether in those monoecious or dioecious1 plants, in which the flowers are widely different, it has ever

1866. Oxalis bowei

349

been observed that half the flower, or only a segment of it, has been of one sex and the other half or segment of the opposite sex; in the same manner as so frequently occurs with insects? Charles Darwin. (We have seen Willow flowers with one stamen, and one stalked carpel. There is also the case of Glochidion, in which three of the cells of a six-celled ovary were developed in the form of anthers. See Lindley, “Elements of Botany,” p. 81. Similar changes have been met with in other Euphorbiaceae. Eds.)

1

Monoecious plants have separate male and female flowers on the same plant, the flowers of dioecious plants are either male or female. See CCD14: 51–2.

1866. [Note on the common broom, Cytisus scoparius.] In Henslow, G., Note on the structure of Indigofera, as apparently offering facilities for the intercrossing of distinct flowers. [Read 19 April] Journal of the Linnean Society of London. Botany 9: 355–8, p. 358. F1737 In the Broom, if the flowers be protected from insects, the parts (stamen and pistil) do not spring out, and scarcely any pods are produced. In a flower lately expanded, when a bee alights on the keel, the shorter stamens alone are ejected, and they dust the abdomen of the insect. When the flower is a day or two older, if a bee alights on the keel, the pistil and longer stamens spring violently out, and the hairs on the pistil deposit plenty of pollen on the bee’s back, against which the stigma is rubbed. When the bee flies away, the pistil curls still more, and the stigmatic surface becomes up-turned, and stands close to the protruded anthers of the shorter stamens. We have seen that the bee gets dusted in its abdomen from the shorter stamens of the younger flowers; and this pollen will be left on the up-turned stigma of the curled pistil of the older flowers. Thus both the upper and lower surface of the bee gets dusted with pollen, which will be transferred to the stigma at two different periods.1

1

George Henslow (1835–1925), clergyman and teacher. Son of J. S. Henslow. See CCD14: 135.

1866. Oxalis bowei. Gardeners’ Chronicle and Agricultural Gazette no. 32 (11 August): 756. F1736 I should be much obliged to any one who will be so kind as to look at his flowers of this Oxalis,1 and observe where the summits of the branching stigmas stand with respect to the two sets of anthers. In all my plants the stigmas stand close beneath the lower anthers; but I have good reason to believe that two other forms exist—one with the stigmas standing above both sets of anthers, and the other with the stigmas between the two sets. If any one has flowers in either of these latter states, that is long-styled or mid-styled, I should be grateful if he would send me a few rather young flowers wrapped up in tin-foil or

350

1866. Cross-fertilising papilionaceous flowers

oil-silk; for I should thus be enabled to fertilize my own flowers and obtain seed. Charles Darwin, Down, Bromley, Kent.

1

Oxalis bowei = Wood sorrel. See CCD14: 291–2.

1866. Cross-fertilising papilionaceous flowers. Gardeners’ Chronicle and Agricultural Gazette no. 32 (11 August): 756. F1737a All who have tried have found much difficulty in crossing papilionaceous flowers. Several years ago, Dr. Herbert1 remarked to me that with the exception of Erythrina no hybrids had been made in this great family. Gärtner crossed 36 flowers of different varieties of the common Pea, and he did not get a single pod perfectly developed and with the full complement of seed; he crossed 10 flowers of Kidney Beans, and did not get a single pod.2 Some years ago I crossed the varieties of the Sweet Pea, and many more flowers dropped off unimpregnated than were fertilised.3 The difficulty arises from the anthers opening at so early an age that they must be removed long before the flower expands. After the operation the immature stigma is liable to exposure to the air; and it is difficult to judge when to apply the pollen. Moreover there is some reason to suspect that the stigma requires successive applications of pollen. To show the difficulty of fertilising papilionaceous flowers, I may mention that I lately removed all the pollen that I could with a soft brush from six recently expanded flowers of Lupinus pilosus protected from the visits of insects, and then applied pollen from a distinct individual of the same species. Although in this case there was no operation at an early age, yet five flowers out of the six dropped off unimpregnated. Had these flowers remained untouched, all, judging from the others, probably would have set, and the only difference would have been that their stigmas would have been surrounded by a mass of pollen as long as the flowers continued in bloom. This case is worth mentioning as showing how erroneous the belief is that fertilisation usually takes place in unopened flowers, in which the pollen is shed at an early age. These trials on the Lupines, and others formerly on Sweet Peas, led me to try the following plan. I rolled up thin paper into a cylinder, rather thinner than a knitting needle. I then tied a thread tight round, and cut off the cylinder beneath the thread, so that a little pipe closed at one end or cap, about the fifth of an inch in length, was left. This was easily filled with pollen from the keel-petal of any desired variety, and could then be placed on the pistil and secured below the stigma by being tied with a thread. I then castrated four flower-buds of the Sweet Pea, and placed on the young stigmas caps filled with pollen from another variety, and four fine pods were soon formed. I also fertilised eight castrated flowers or two species of Lupins with pollen from distinct plants of the same species, but from these I have got only four pods. I may add, that as an experiment I filled one of the little caps with pollen of Lathyrus grandiflorus and placed it on the stigma of a Sweet Pea (Lathyrus odoratus), and to my great surprise, considering how distinct these species are, a fine pod has been formed. I am certain no pollen could have been left in the flower of the Sweet Pea, as the anthers were removed whilst quite

1867. Queries about expression

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immature; and if these hybrid seeds grow, a curious hybrid will be produced. I should not have thought this plan of fertilising papilionaceous flowers worth mentioning had it not been applicable in all cases in which early castration is necessary, and likewise in certain cases mentioned by Gärtner, in which the stigma requires, or is benefited by, successive applications of pollen. In all such cases some trouble would be saved and certainty gained by the use of the little caps filled with the desired kind of pollen. Charles Darwin, Down, Bromley, Kent.

1 2 3

William Herbert. See CCD14: 292–3. CD discussed Leguminosae in Natural selection, pp. 68–71. Gärtner 1849, p. 720. For CD’s experiments with sweetpeas see Natural selection, pp. 70–1.

1866. Feet of otter hounds. Land and Water (6 October): 244. F1930 Sir,—I should be very much obliged to any one who keeps otter hounds if he would have the kindness to examine the feet of two or three dogs, and compare them with respect to the membrane between the toes with some other dog of a named breed. It would be best to compare the feet with those of some other sort of hound. With some otter hounds the skin between the toes is certainly more largely developed than in the case of common dogs, and I am anxious to know whether this is the general rule. It should be stated to which part or joint of the toes the skin extends, and whether it is much hollowed out in the middle. I should be very grateful for information sent to me either by letter or through Land and Water. Charles Darwin. Down, Bromley, Kent.1

1

See CCD14: 338. CD referred to a response to this query by Charles Otley Groom-Napier from Land and Water (13 October 1866): 270. ‘English otter-hounds are said to have webbed feet: a friend examined for me the feet of two, in comparison with the feet of some harriers and bloodhounds; he found the skin variable in extent in all, but more developed in the otter than in the other hounds.’ Variation 1: 39–40.

1867. Queries about expression. np: np. F8761 (1.) Is astonishment expressed by the eyes and mouth being opened wide, and by the eyebrows being raised? (2.) Does shame excite a blush when the colour of the skin allows it to be visible? and especially how low down the body does the blush extend? (3.) When a man is indignant or defiant does he frown, hold his body and head erect, square his shoulders and clench his fists?

352

1867. Queries about expression

(4.) When considering deeply on any subject, or trying to understand any puzzle, does he frown, or wrinkle the skin beneath the lower eyelids. (5.) When in low spirits, are the corners of the mouth depressed, and the inner corner of the eyebrows raised by that muscle which the French call the “Grief muscle?”2 The eyebrow in this state becomes slightly oblique, with a little swelling at the inner end; and the forehead is transversly wrinkled in the middle part, but not across the whole breadth, as when the eyebrows are raised in surprise. (6.) When in good spirits do the eyes sparkle, with the skin a little wrinkled round and under them, and with the mouth a little drawn back at the corners? (7.) When a man sneers or snarls at another, is the corner of the upper lip over the canine or eye tooth raised on the side facing the man whom he addresses? (8.) Can a dogged or obstinate expression be recognized, which is chiefly shewn by the mouth being firmly closed, a lowering brow; and a slight frown? (9.) Is contempt expressed by a slight protrusion of the lips and by turning up the nose, with a slight expiration? (10.) Is disgust shewn by the lower lip being turned down, the upper lip slightly raised, with a sudden expiration, something like incipient vomiting, or like something spat out of the mouth? (11.) Is extreme fear expressed in the same general manner as with Europeans? (12.) Is laughter ever carried to such an extreme as to bring tears into the eyes? (13.) When a man wishes to shew that he cannot prevent something being done, or cannot himself do something, does he shrug his shoulders, turn inwards his elbows, extend outwards his hands and open the palms; with the eyebrows raised? (14.) Do the children when sulky, pout or greatly protrude the lips? (15.) Can guilty, or sly, or jealous expressions be recognized? though I know not how these can be defined. (16.) As a sign to keep silent, is a gentle hiss uttered? (17.) Is the head nodded vertically in affirmation, and shaken laterally in negation? Observations on natives who have had little communication with Europeans would be of course most valuable, though those made on any natives would be of much interest to me. General remarks on expression are of comparatively little value; and memory is so deceptive that I earnestly beg it may not be trusted. A definite description of the countenance under any emotion or frame of mind, with a statement of the circumstances under which it occurred, would possess much value. An answer within six or eight months, or even a year, to any single one of the foregoing questions would be gratefully accepted. In sending answers, the questions need not be copied, but reference may be made to the numbers of each query. Charles Darwin, Down, Bromley, Kent, 1867.

1867. Cut or uncut

1

2

353

Answers to the queries were used in writing Expression, where a list of sixteen queries is given on pp. 15–16. Darwin introduced them with the following remarks: Fifthly, it seemed to me highly important to ascertain whether the same expressions and gestures prevail, as has often been asserted without much evidence, with all the races of mankind, especially with those who have associated but little with Europeans. Whenever the same movements of the features or body express the same emotions in several distinct races of man, we may infer with much probability, that such expressions are true ones, that is, are innate or instinctive. Conventional expressions or gestures, acquired by the individual during early life, would probably have differed in the different races, in the same manner as do their languages. Accordingly I circulated, early in the year 1867, the following printed queries with a request, which has been fully responded to, that actual observations, and not memory, might be trusted. See CCD15. The copy used here is from DAR53.1.B2. (DO) Multiple printings of the queries are analysed and responses reprinted in Freeman and Gautrey 1972 and 1975 (except Darwin 1874, F1832, not then known). The queries were apparently translated and printed in German in ‘the instructions for the commercial Reporters’ by Karl von Scherzer (1821–1903), principal scientist of the Novara expedition, but the item has not been traced. See Cal: 6425 and 6429. The queries were later published: [Darwin] 1867, F1739, by Robert Swinhoe (1836–77), an ornithologist and consular official stationed at Amoy, China 1865–73. No replies were published; Darwin 1868, F874; and Darwin 1874, F1832 where they are listed in the table of contents, under ‘Part I.—Constitution of Man’ reads: ‘IX. Physiognomy. By C. Darwin, Esq., F.R.S.—Questions as to the expression of the countenance, natural gestures, blushing &c.’ Compare with Darwin 1841, F1975. (DO) On Expression see Ekman 1989. Grief muscle = corrugator supercilii.

1867. Cut or uncut. Athenæum no. 2045 (5 January): 18–19. F18151 Down, Bromley, Kent Jan. 1, 1867. I was glad to see in your paper of the 15th ult. that you have allowed “A Great Reader” to protest against books being sold uncut.2 He is obliged to own that many persons like to read and cut the pages at the same time; but, on the other hand, many more like to turn rapidly over the pages of a new book so as to get some notion of its contents and see its illustrations, if thus ornamented. But “A Great Reader” does not notice three valid objections against uncut books. In the first place they sometimes get torn or badly cut, as may be seen with many books in Mudie’s Library;3 and I know a lady who is habitually guilty of cutting books with her thumb. Secondly, and which is much more important, dust accumulates on the rough edges, and gradually works in between the leaves, as the books vibrate on their shelves. Thirdly, and most important of all, for those who not merely read but have to study books, is the slowness in finding by the aid of the index any lost passage, especially in works of reference. Who could tolerate a dictionary with rough edges? I have had Loudon’s ‘Encyclopaedia of Plants’ and Lindley’s ‘Vegetable Kingdom’ in constant use during many years, and the cloth binding is still so good that it would have been a useless expense |19| to have had them bound in leather; nor did I foresee that I should have consulted them so often, otherwise the saving of time in finding passages would have amply repaid the cost of binding. The North Americans have set us the example of cutting and often gilding the

354

1867. Fertilisation of Cypripediums

edges. What can be the reason that the same plan is not followed here? Is it mere Toryism? Every new proposal is sure to be met by many silly objections. Let it be remembered that a deputation of paper-manufacturers waited on Sir R. Peel, when he proposed to establish the penny postage, urging that they would suffer great loss, as all persons would write on notepaper instead of on letter sheets! It is always easy to suggest fanciful difficulties. An eminent publisher remarked to me that booksellers would object to receiving books cut, as customers would come into their shops and read them over the counter; but surely a book worth reading could not be devoured in this hasty manner. The sellers of old books seem never to object to any one studying the books on their stalls as long as he pleases. “A Discursive” remarks in your paper that booksellers would object to books being supplied to them with their edges cut, as they would thus “relinquish an obvious advantage in palpable evidence of newness.”4 But why should this objection be more valid here than in America? Publishers might soon ascertain the wishes of the public if they would supply to the same shop cut and uncut copies, or if they would advertise that copies in either state might be procured, for booksellers would immediately observe which were taken in preference from their counters. I hope that you will support this movement, and earn the gratitude of all those who hate the trouble and loss of time in cutting their books, who lose their paper-cutters, who like to take a hasty glance through a new volume, who dislike to see the edges of the pages deeply stained with dust, and who have the labour of searching for lost passages. You will not only earn the gratitude of many readers, but in not a few cases that of their children, who have to cut through dry and pictureless books for the benefit of their elders. Charles Darwin.

1 2 3 4

This letter was written in response to: ‘A great reader’ 1866. CD’s letter was reprinted in The Times (7 January 1867): 8. See CCD15: 1–3. ‘A great reader’ 1866. Mudie’s Select Library, New Oxford Street, London, a subscription lending library. ‘A discursive’ 1866.

1867. Fertilisation of Cypripediums. Gardeners’ Chronicle and Agricultural Gazette no. 14 (6 April): 350. F1738 The specimens forwarded [of Cypripedium insigne or Lady’s-slipper orchid] appeared on examination to be perfectly formed as regards their stamens and pistils, but perfectly destitute of ovules. On forwarding them to Mr. Darwin, that gentleman kindly favoured us with the following remarks. Eds.:—1 From the remarkable fact lately ascertained by Dr. Hildebrand,2 that with many Orchids the ovules do not become developed until many weeks or even months have elapsed after the pollen-tubes have penetrated the stigma, it is not a little difficult to ascertain whether any Orchis is exclusively a male plant, that is, whether the female organs have aborted. Of course there is no difficulty in ascertaining the rudimentary condition of the pollen, and so ascertaining that a plant is a female. The explanation of the sterility of the seed-capsules in the Cypripediums sent to me I have little doubt lies in the circumstance of their having

1867. Hedgehogs

355

been fertilised by pollen taken from the same plant or seedling. I now know of a long series of cases in which various Orchids are absolutely sterile when impregnated by their own pollen (proved, however, to be in itself effective), but which can be easily impregnated by pollen taken from other individuals of the same species, or from distinct species. These facts strike me as most remarkable under a physiological point of view, and they point to the necessity of an occasional or regular union between distinct individuals of the same species. Ch. Darwin.

1

2

The editorial note and Darwin’s letter were a response to the following note: As the sexes of Orchids form a subject of considerable interest, I beg to forward you the accompanying specimens of Cypripedium insigne. [Lady’s-slipper orchid.] Of this I have several plants, all however originally derived from the same piece, but in spite of numerous attempts, I have uniformly failed to fertilise the flowers. The seed-vessel swells and the flower fades as usual, but no seed is produced. It appears to me that my plant produces a male flower only, and is not hermaphrodite. Have any others of your correspondents made a similar observation? I enclose a flower of Cypripedium insigne and two barren seed-vessels, to which the pollen of C. barbatum and C. venustum was applied this year. To prove that the pollen masses of the plant in question are good, I send also a seed-vessel of C. barbatum, fertilised with the pollen of one of the same flowers of C. insigne, and which is full of seeds. A. D. B. [A.D.B. has not been identified.] See CCD15: 182–4. Friedrich Hildebrand (1835–1915), German botanist. Hildebrand 1866.

1867. Hedgehogs. Hardwicke’s Science Gossip 3, no. 36 (1 December): 280. F1740 As in the August and September numbers,1 you have published an account of hedgehogs apparently carrying away pears and crabs sticking on their spines, you may think the following statement worth insertion as a further corroboration. I have received this account in a letter dated August 5, 1867, from Mr. Swinhoe at Amoy:—“Mr. Gisbert,2 the Spanish Consul at Amoy, informs me that when he was an engineer on the roads in Spain some years ago, he was fond of shooting and roaming about the country. He states that in the Sierra Morena, a strawberry-tree (Arbutus unedo?) was very abundant, and bore large quantities of red, fruit-like, fine, large, red strawberries. These gave quite a glow to the woods. The district in the mountain chain he refers to, is on the divisional line between the provinces of Seville and Badajos. Under these trees hedgehogs occurred innumerable, and fed on the fruit, which the Spaniards call Madrône.3 Mr. Gisbert has often seen an Erizo (hedgehog) trotting along with at least a dozen of these strawberries sticking on its spines. He supposes that the hedgehogs were carrying the fruit to their holes to eat in quiet and security, and that to procure them they must have rolled themselves on the fruit which was scattered in great abundance all over the ground beneath the trees.”—Charles Darwin.

1 2 3

B. L. 1867 and A. B. F. 1867. See CCD15: 450–1. Mr. Gisbert has not been identified. Madroño = Arbutus unedo, the strawberry tree.

1868. On the specific difference between Primula veris

356

1868. On the character and hybrid-like nature of the offspring from the illegitimate unions of dimorphic and trimorphic plants. [Read 20 February] Journal of the Linnean Society of London. Botany 10: 393–437. F17421

1

An edited version of this paper was later published in Forms of flowers (1877); it is therefore omitted here. See Darwin 1862, F1717. (p. 321) CD explained his terms at the beginning of this paper: Dimorphic species consist of two forms, which naturally exist in about equal numbers: in the long-styled form the pistil is always longer, and the stamens…are shorter than in the other form. Conversely, in the short-styled form the pistil is shorter and the stamens longer than in the long-styled form. … The sexual union of the two distinct forms is necessary for full fertility … With trimorphic species…There are three forms, which differ greatly in the length of the pistil; and in each form two sets of stamens exist, differing in length, in the size of the pollen-grains, and often in colour. The stamens are graduated in length, so that one of the two sets in two of the forms is equal in length to the pistil in the third form. …Thus the long-styled form can be legitimately fertilized only by the longer stamens of the mid-styled or short-styled form; it can be illegitimately fertilized by its own two sets of stamens, and by the shorter stamens of both the mid-styled and short-styled forms; so that the long-styled form can be fertilized legitimately in two ways and illegitimately in four ways. The same holds good with the mid-styled and short-styled forms; hence with trimorphic species eighteen unions are possible, of which six are legitimate, and produce legitimate offspring, and twelve are illegitimate and produce illegitimate offspring.

1868. [Inquiry about sex ratios in domestic animals]. Gardeners’ Chronicle and Agricultural Gazette no. 7 (15 February): 160. F1743 Sir,—I should be very much obliged to you or to any of your readers, if they would have the great kindness to refer me to any observations which may have been published on the proportional number of males and females born to our various domestic animals, such as cattle, sheep, horses, dogs, poultry, ducks, &c. I presume that this point has often been attended to, but I am at a loss where to search, and should be grateful for any reference or for any unpublished facts. Sir, your obedient servant, Charles Darwin. Down, Bromley, Kent, S.E., Feb. 11.1

1

See Descent 1: 318.

1868. On the specific difference between Primula veris, Brit. Fl. (var. officinalis, of Linn.), P. vulgaris, Brit. Fl. (var. acaulis, Linn.) and P. elatior, Jacq.; and on the hybrid nature of the common Oxlip. With supplementary remarks on naturally-produced Hybrids in the genus Verbascum. [Read 19 March] Journal of the Linnean Society of London. Botany 10: 437–54. F17441

1

An edited version of this paper was later published in Forms of flowers (1877); it is therefore omitted here. See Darwin 1862, F1717 (p. 322).

1869. The formation of mould by worms

357

n.d. [Printed acknowledgement of correspondence]. np: np. F1958 Down, Beckenham, Kent. Mr. Darwin is much obliged for the letter just received. Owing to the large number of communications which daily arrive, he regrets to say that it is almost impossible for him to do more than to acknowledge their receipt and express his thanks.1

1

The date of this item is not known. It is post-1867 because in 1868 Downe village ceased to be in Bromley and became part of Beckenham. Francis Darwin recalled ‘[CD] had a printed form to be used in replying to troublesome correspondents, but he hardly ever used it; I suppose he never found an occasion that seemed exactly suitable.’ LL1: 120.

1869. The formation of mould by worms. Gardeners’ Chronicle and Agricultural Gazette no. 20 (15 May): 530. F1745 As Mr. Fish asks me in so obliging a manner whether I continue of the same opinion as formerly in regard to the efficiency of worms in bringing up within their intestines fine soil from below, I must answer in the affirmative.1 I have made no more actual measurements, but I have watched during the last 25 years the gradual, and at last complete, disappearance of innumerable large flints on the surface of a field with very poor soil after it had been laid down as pasture. I have also purposely covered a few yards square of a grass-field with fine chalk, so as to observe the worms burrowing up through it, and leaving their castings on the surface, which were soon spread out by the rain. The Regent’s Park in early autumn is a capital place to observe the wonderful amount of work effected under favourable circumstances by worms, even in the course of a week or two. My observations in Staffordshire were chiefly made on poor, sandy grass-land, and I think that Mr. Fish will find that the proportion by weight or measure of carbon in poor soil is but small, and that the decay of the Grass will account for but a small proportion of the matter successively deposited on the surface. Except when peat or peaty soil is forming, the carbon compounds seem soon to be decomposed and disappear. Judging from the quick rate at which I have proved that the surface becomes covered with fine soil, if the mere decay of the Grass were as effective as Mr. Fish thinks, many feet in thickness would be formed in the course of a few centuries—a result which would be as surprising as delightful to the dwellers on poor land, or indeed on any land, which is never overflowed by mud-bearing water. In ordinary soils the worms do not burrow down to great depths, consequently fine vegetable soil is not accumulated to any inordinate thickness. Charles Darwin, May 9.

1

David Taylor Fish (1824–1901), London gardener and botanical author writing in Gardeners’ Chronicle (17 April) 1869, p. 418. Fish was referring to CD’s views expressed in Darwin 1838, F1648 (p. 48) and 1840, F1655 (p. 124). CD later referred to this objection in Earthworms (1881) p. 6:

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1869. Origin of species [On reproductive potential of elephants]

In the year 1869, Mr. Fish rejected my conclusions with respect to the part which worms have played in the formation of vegetable mould, merely on account of their assumed incapacity to do so much work. He remarks that “considering their weakness and their size, the work they are represented to have accomplished is stupendous.” Here we have an instance of that inability to sum up the effects of a continually recurrent cause, which has often retarded the progress of science, as formerly in the case of geology, and more recently in that of the principle of evolution.

1869. Origin of species [On reproductive potential of elephants]. Athenaeum no. 2174 (26 June): 861. F1746 Caerleon, North Wales, June 19, 1869. I am much obliged to your Correspondent1 of June 5 for having pointed out a great error in my ‘Origin of Species,’ on the possible rate of increase of the elephant. I inquired from the late Dr. Falconer2 with respect to the age of breeding, &c., and understated the data obtained from him, with the intention, vain as it has proved, of not exaggerating the result. Finding that the calculation was difficult, I applied to a good arithmetician; but he did not know any formula by which a result could easily be obtained; and he now informs me that I then applied to some Cambridge mathematician. Who this was I cannot remember, and therefore cannot find out how the error arose. From the many familiar instances of rapid geometrical increase, I confess that, if the answer had been thirty or sixty million elephants, I should not have felt much surprise; but I ought not to have relied so implicitly on my mathematical friend. I have misled your Correspondent by using language which implies that the elephant produces a pair of young at each birth; but the calculation by this assumption is rendered easier and the result but little different. A friend has extended your Correspondent’s calculation to a further period of years. Commencing with a pair of elephants, at the age of thirty, and assuming that they would in each generation survive ten years after the last period of breeding—namely, when ninety years old—there would be, after a period of 750 to 760 years (instead of after 500 years, as I stated in ‘The Origin of Species’), considerably more than fifteen million elephants alive, namely, 18,803,080. At the next succeeding period of 780 to 790 years there would be alive no less than 34,584,256 elephants. Charles Darwin.

1

2

Ponderer 1869. In Origin p. 64 CD wrote: The elephant is reckoned to be the slowest breeder of all known animals, and I have taken some pains to estimate its probable minimum rate of natural increase: it will be under the mark to assume that it breeds when thirty years old, and goes on breeding till ninety years old, bringing forth three pair of young in this interval; if this be so, at the end of the fifth century there would be alive fifteen million elephants, descended from the first pair. Ponderer objected that there would be ‘85,524 elephants, less the number that would have died by reason of their age.’ Hugh Falconer (1808–65), physician and palaeontologist who worked for several years in India.

1869. Origin of species [On reproductive potential of elephants]

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1869. Origin of species [On reproductive potential of elephants]. Athenaeum no. 2177 (17 July): 82. F1747 Caerdeon, Barmouth, June 7, 1869. I have received a letter from Germany on the increase of the elephant, in which a learned Professor arrives at a totally different result from that of Mr. Garbett,1 both of which differ from that of your Correspondent ‘Ponderer.’ Hence you may perhaps think it worth while to publish a rule by which my son, Mr. George Darwin,2 finds that the product for any number of generations may easily be calculated: — “The supposition is that each pair of elephants begins to breed when aged 30, breeds at 60, and again, for the last time, at 90, and dies when aged 100, bringing forth a pair at each birth. We start, then, in the year 0 with a pair of elephants, aged 30. They produce a pair in the year 0, a pair in the year 30, a pair in the year 60, and die in the year 70. In the year 60, then, there will be the following pairs alive, viz.: one aged 90, one aged 60, two aged 30, four aged 0. The last three sets are the only ones which will breed in the year 90. At each breeding a pair produces a pair, so that the number of pairs produced in the year 90 will be the sum of the three numbers 1, 2, 4, i.e. 7. Henceforward, at each period, there will be sets of pairs, aged 30, 60, 90 respectively, which breed. These sets will consist of the pairs born at the three preceding periods respectively. Thus the number of pairs born at any period will be the sum of the three preceding numbers in the series, which gives the number of births at each period; and because the first three terms of this series are 1, 2, 4, therefore the series is 1, 2, 4, 7, 13, 24, 44, &c. These are the numbers given by ‘Ponderer.’ At any period, the whole number of pairs of elephants consists of the young elephants together with the three sets of parents; but since the sum of the three sets of parents is equal in number to the number of young ones, therefore the whole number of pairs is twice the number of young ones, and therefore the whole number of elephants at this period (and for ten years onwards) is four times the corresponding number in the series. In order to obtain the general term of the series, it is necessary to solve an easy equation by the Calculus of Finite Differences.”3

Charles Darwin.

1 2 3

Edward Lacy Garbett (1817–87), clergyman and writer. Garbett 1869 claimed there would be 2,400,000 elephants after 500 years and 50,000,000 after 600. George Howard Darwin (1845–1912), CD’s fifth child, mathematician and from 1883 Plumian Professor of Astronomy and Experimental Philosophy at Cambridge University. See Natural selection p. 177. There is a sheet of computations on the elephant problem in DAR46.1.35–36 by George Darwin. (DO) One set calculates that based on four sets of young (one pair per set) produced by parents 15,111,870 offspring would be alive after twenty-five generations. The other set calculated the same progression series given by ‘Ponderer’ and resulted in 5,111,514. Barrett 1977 2: 158 concluded: ‘Thus, when writing the Origin of Species in 1858–9, CD seems inadvertently to have copied the conditions of the problem from one sheet, and the answer from the second.’ In the 6th and final ed. of Origin in 1872, p. 51 CD wrote: The elephant is reckoned the slowest breeder of all known animals, and I have taken some pains to estimate its probable minimum rate of natural increase; it will be safest to assume that it begins breeding when thirty years old, and goes on breeding till ninety years old, bringing forth six young in the interval, and surviving till one hundred years old; if this be so, after a period of from 740 to 750 years there would be nearly nineteen million elephants alive, descended from the first pair.

1869. [Extract of a letter on fertilisation of Vinca by insects]

360

1869. Notes on the fertilization of orchids. By Charles Darwin, M.A., F.R.S., &c. Annals and Magazine of Natural History (Ser. 4) 4 (September): 141–59. F1748 To the Editors of the Annals and Magazine of Natural History Gentlemen, Having drawn up some notes for a French translation of my work ‘On the various contrivances by which British and Foreign Orchids are Fertilized by Insects’ (1862), it has appeared to me that these notes would be worth publishing in English.1 I have thus been able to bring up the literature of the subject to the present day, by giving references to, together with very brief abstracts of, all the papers published since my work appeared. These papers contain, on the one hand, corrections of some serious errors into which I had fallen, and, on the other hand, confirmations of many of my statements. I have also been able to add, from my own observations and those of others, a few new facts of interest. A heading is given to each note, which will show the nature of the correction or addition, without any reference to my book; but I have added in a parenthesis the page to which the note ought to be appended. Gentlemen, Your obedient Servant, Charles Darwin.Down, Beckenham, Kent. July 23, 1869.

1

The French ed. of Orchids appeared in 1870 (Rérolle trans. 1870); the 2d English ed. appeared in 1877 incorporating the changes that followed this letter; they are omitted here.

1869. [Extract of a letter on fertilisation of Vinca by insects]. In Bennett, A. W., Fertilisation of winter-flowering plants. Nature 1 (11 November): 58. F1971 Mr. Darwin has done me the honour of calling my attention to one or two points in my paper, published in your last number, “On the Fertilisation of Winter-flowering Plants.”1 He thinks there must be some error in my including Vinca major among the plants of which the pollen is discharged in the bud, as he “knows from experiment that some species of Vinca absolutely require insect aid for fertilisation.” […] The second point relates to the white dead-nettle, with respect to which Mr. Darwin says, “I covered up Lamium album early in June, and the plants produced no seed, although surrounding plants produced plenty.” […] Alfred W. Bennett2 3, Park Village East, Nov. 8, 1869

1 2

Bennett 1869. CD responded in Darwin 1869, F1748a (p. 361). Alfred William Bennett (1833–1902), botanist and publisher.

1869. Pangenesis.—Mr. Darwin’s reply to Professor Delpino

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1869. The fertilisation of winter-flowering plants. Nature 1 (18 November): 85. F1748a Will you permit me to add a few words to Mr. Bennett’s letter,1 published at p. 58 of your last number? I did not cover up the Lamium with a bell-glass, but with what is called by ladies, “net.” During the last twenty years I have followed this plan, and have fertilised thousands of flowers thus covered up, but have never perceived that their fertility was in the least injured. I make this statement in case anyone should be induced to use a bell-glass, which I believe to be injurious from the moisture of the contained air. Nevertheless, I have occasionally placed flowers, which grew high up, within small wide-mouthed bottles, and have obtained good seed from them. With respect to the Vinca, I suppose that Mr. Bennett intended to express that pollen had actually fallen, without the aid of insects, on the stigmatic surface, and had emitted tubes. As far as the mere opening of the anthers in the bud is concerned, I feel convinced from repeated observations that this is a most fallacious indication of self-fertilisation [= self-pollination]. As Mr. Bennett asks about the fertilisation of Grasses, I may add that Signor Delpino,2 of Florence, will soon publish some novel and very curious observations on this subject, of which he has given me an account in a letter, and which I am glad to say are far from being opposed to the very general law that distinct individual plants must be occasionally crossed. Charles Darwin Down, Beckenham, Kent, Nov. 13

1

2

Bennett 1869. Giacomo Guiseppe Federico Delpino (1833–1905), Italian botanist and professor of Botany at Genoa and later at Naples. CD was responding to the criticisms of Delpino 1869 of pangenesis, see below.

1869. Pangenesis.—Mr. Darwin’s reply to Professor Delpino. Scientific Opinion 2 (20 October): 426. F1748b I could say something in answer to most of Delpino’s ingenious criticisms,1 but I will confine myself to one point; remarking, however, that I cannot see the force of his objection to the belief that the gemmules have the power of self-division. The analogy of the multiplication within the body of an infected person of the contagious atoms of small-pox or scarlet-fever still seems to me fair. The criticism which at first struck me as much the most forcible, relates to the re-growth of an amputated limb or other organ. I have assumed, from what we know of the ordinary laws of growth, that gemmules become developed only when united with the nascent or very young cells which precede them in the due order of successive development. Now, Delpino remarks that when the limb of a mature salamander is cut off, nascent cells would not exist on the stump, but only mature ones; consequently, as he urges, the gemmules, according to the hypothesis, could not be there developed and form a new limb. But have we any reason for assuming that with animals the same cells or organic

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1869. Pangenesis.—Mr. Darwin’s reply to Professor Delpino

units endure throughout life and are not replaced by new cells? All physiologists admit that the whole frame is being constantly renovated. The bones, which it might be thought would be least capable of renewal, undergo before maturity great changes in form and size and in the diameter of the medullary canal; even after maturity their shape does not remain the same. If, then, it be admitted that the tissues throughout the body are constantly being renovated by means of the old cells giving birth through proliferation or division to new cells, the difficulty of the gemmules being developed at any point at which a limb may be cut off, disappears; for some nascent cells would exist there; and we must bear in mind that gemmules may possibly become developed in union with cells which are not strictly the proper ones, as shown in the extreme case of nails occasionally growing on the stumps of the amputated fingers of man. It is probable that the renovation of the tissues by the formation of new cells becomes less and less in old age, and so does the power of regrowth. The curious fact that insects which live but a short time after their final metamorphosis, have singularly little power of regrowth, may be partly explained by the deficiency in their tissues of nascent cells. In the case of plants, the cells composing the tissues endure for life, and are not renewed. The woody cells in the trunk of a tree originally existed as delicate cells in the young shoot. Now, it is remarkable, considering how low plants stand in the scale of life, what little power of re-growth most of their organs or parts possess, not withstanding their high vitality. Cut off a young shoot, and the next bud below will form a new shoot; cut off an old stem, and hundreds of adventitious buds will be formed. No one, I believe, ever saw a mutilated leaf repaired in the same manner as the limb of a salamander; yet on the cut margins of certain leaves innumerable buds will be quickly developed. In the bark, on the other hand, new cells must be continually forming, for the outer layers are continually being thrown off, and bark can certainly reproduce itself on a decorticated surface (see Professor Oliver in Transactions of Tyneside Club, vol. iii. 1855, p. 67),2 from an isolated point not connected with the surrounding uninjured bark; so that this case is fairly analogous with that of the re-growth of an amputated limb. I will add only one other remark. Delpino insists that, according to the hypothesis, the same cells must throw off gemmules at many successive periods of their development. But I can see no such necessity. Certain epidermic cells, for instance, form horn; but their conversion into this substance is apparently due to the chemical nature of the contents of the cells; and of the changes consequent on the absorption of certain elements. An atom or gemmule thrown off at an early period from one of these cells would, when properly nourished, first form a cell like the parent cell, and ultimately be converted into horn, without the necessity of throwing off successive gemmules. As, however, a cell is a complex structure, with its investing membrane, nucleus, and nucleolus, a gemmule, as Mr. G. H. Lewes3 has remarked in his interesting discussion on this subject (Fortnightly Review, Nov. 1, 1868, p. 508), must, perhaps, be a compound one, so as to reproduce all the parts. The attack by Delpino on the weak point of the hypothesis, namely, that it requires the support of several subordinate hypotheses, is perfectly just, though perhaps pushed to an extreme. But I can speak from recent experience, that he who has to consider complex cases of inheritance, as limited either separately or conjointly by sex, age, and season, with the inherited characters themselves and the form of inheritance liable to change from crossing and variability, will be able

1870. [Note on the age of certain birds]

363

to disentangle the phenomena much more clearly, if he admits for the time our hypothesis with all its imperfections. He will then have fixed in his mind that transmission and development are quite distinct phenomena,—the gemmules being thrown off from all parts of the organization, and transmitted from both parents to both sexes at the earliest age,—their development alone depending on the nature of the nascent tissues of the individual, whether permanently or temporarily modified by sex, age, season of the year, or other conditions. Charles Darwin. Down, Beckenham, Kent.

1

2 3

Giacomo Guiseppe Federico Delpino. CD was responding to the criticisms of Delpino 1869 to CD’s ‘Provisional hypothesis of pangenesis’, Chapter 27 in Variation 2: 357–404. The editors of Scientific Opinion introduced this item with a footnote: ‘Professor Delpino’s opinions, as translated from the Rivista Contemporanea Nazionale Italiana, having appeared very fully in our columns, we have requested Mr. Darwin to reply to them. To this Mr. Darwin has complied, and we believe that the natural history world will be interested in reading the following remarks.—Ed. S.O.’ CD’s notes on Oliver are in DAR51.C1. (DO) Oliver 1855. George Henry Lewes (1817–78), prominent writer. Lewes 1868.

1870. [Letter on marine shells in the Amazon]. In Orton, J. 1870. The Andes and the Amazon; or, across the continent of South America. New York: Harper & brothers, p. [347]. F1990 Your discovery of marine shells high up the Amazon possesses extreme interest, not only in itself, but as one more most striking instance how rash it is to assert that any deposit is not a marine formation because it does not contain fossils. As for myself, I never believed for a moment in Agassiz’s idea of the origin of the Amazonian formation.1

1

James Orton (1830–77), American zoologist, clergyman, explorer and Professor of natural history, Vassar College, 1869–77. This letter corresponds to Cal: 6570. Agassiz believed the Amazonian formation was formed from glacial deposits from the Andes. Agassiz and Agassiz 1868, pp. 250, 411, 424.

1870. [Note on the age of certain birds]. In Lankester, E. R. On comparative longevity in man and the lower animals. London: Macmillan, p. 58. F19911 The following seven facts were communicated by Mr. Darwin:— * Saxicola sialis, for 10 years and more was observed to build its nest in same spot. (‘Amer. Jour. Sci.’ vol. 30, p. 81.)2 * Muscicapa fusca, 9 years; same observation. * Turdus, for a longer period.

364

* * * *

1

2 3 4

1870. Memorial to the Right. Hon. the Chancellor of the Exchequer

Falco borealis, 12 years. Starling, for 8 years the same lame specimen was observed by Eckmark.3 Kestrel, for 6 years the same specimen was seen. Goldfinch, lived 23 years in confinement. (Montagu.)4

Edwin Ray Lankester (1847–1929), zoologist. On p. 13 Lankester wrote: ‘In reply to enquiries, Mr. Charles Darwin writes that he has no information with regard to the longevity of the nearest wild representatives of our domesticated animals, nor notes as to the longevity of our quadrupeds.’ In a footnote: ‘Mr. Darwin very kindly furnished me with a note relative to the age of certain birds, which is quoted in the Table of Statements, which follows.’ The table containing CD’s facts is entitled ‘Statements as to Duration of the Individual in Organisms.’ ‘an asterisk [is placed] against the most soundly based of the statements made.’ p. 62. Bachman 1836. These facts appear in Natural selection, p. 184, note 2. Ekmarck 1781. Montagu 1831.

1870. [Note on Darwin’s papers to the Plinian Society 27 March 1827.] In Elliot, W., Opening address by the President. Transactions of the Botanical Society of Edinburgh 11: 1–42. F1749 The first paper contributed by him, entitled “On the Ova of the Flustra,” in which he announces that he has discovered organs of motion, and, secondly, that the small black body hitherto mistaken for the young of Fucus loreus is in reality the ovum of Pontobdella muricata, exhibits his early habits of minute investigation.1

1

See Barrett 1977, 2: 285–91. This note was reprinted in Darwin 1873, F1764. CD pasted the latter into the front of his Journal (DAR158). CD recalled in his Autobiography: ‘The Plinian Society … consisted of students and met in an underground room in the University [of Edinburgh] for the sake of reading papers on natural science and discussing them. I used regularly to attend and the meetings had a good effect on me in stimulating my zeal and giving me new congenial acquaintances.’

1870. Memorial to the Right. Hon. the Chancellor of the Exchequer. [W. E. Gladstone]. Nature 2 (16 June): 118. F869 Natural History Collections1 Allow me to give in my adhesion to the “platform” established by the signers of the Memorial concerning the Natural History Collections, reprinted in your last number, and at the same time to request you to reprint a second Memorial on the same subject, presented in 1866 to the then Chancellor of the Exchequer. You will observe that this Memorial has likewise been signed by many distinguished men of science. P. L. Sclater2

1870. Notes on the habits of the pampas woodpecker (Colaptes campestris)

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Copy of a Memorial presented to the Right Hon. the Chancellor of the Exchequer Sir,—It having been stated that the scientific men of the Metropolis are, as a body, entirely opposed to the removal of the Natural History Collections from their present situation in the British Museum, we, the undersigned Fellows of the Royal, Linnean, Geological, and Zoological Societies of London, beg leave to offer to you the following expression of our opinion upon the subject. We are of opinion that it is of fundamental importance to the progress of the Natural Sciences in this country, that the administration of the National Natural History Collections should be separated from that of the Library and Art Collections, and placed under one officer, who should be immediately responsible to one of the Queen’s Ministers. We regard the exact locality of the National Museum of Natural History as a question of comparatively minor importance, provided that it be conveniently accessible and within the Metropolitan district. Charles Darwin, F.R.S., F.L.S., F.Z.S. [The other 24 names are omitted.] London, May 14, 1866

1 2

This memorial was later republished in Darwin 1873, F1766. See CCD14: 174–6. Philip Lutley Sclater (1829–1913), ornithologist and animal geographer.

1870. [Letter of apology regarding the honorary degree ceremony at Oxford]. The Times (20 June): 11. F1940 N.B. The name of Charles Darwin, Esq., F.R.S., would have been included in the foregoing list, but he writes that his health is such that he “could not withstand the fatigue and excitement of receiving an honorary degree.”1

1

This is an extract from a letter by CD apologizing for not attending the honorary degree ceremony (for a D.C.L.) at Oxford in June 1870. CD later accepted an honorary LL.D degree from Cambridge in 1877. The same extract was reprinted in Nature (23 June 1870): 148.

1870. Notes on the habits of the pampas woodpecker (Colaptes campestris). By Charles Darwin, F.R.S. [Read 1 November] Proceedings of the Zoological Society of London no. 47: 705–6. F1750 In the last of Mr. Hudson’s1 valuable articles on the ornithology of Buenos Ayres,* he remarks, with respect to my observations on the Colaptes campestris, that it is not possible

*

P.Z.S. 1870, p. 158.

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1870. Notes on the habits of the pampas woodpecker (Colaptes campestris)

for a naturalist “to know much of a species from seeing perhaps one or two individuals in the course of a rapid ride across the Pampas.” My observations were made in Banda Oriental, on the northern bank of the Plata, where, thirty-seven years ago, this bird was common; and during my successive visits, especially near Maldonado, I repeatedly saw many specimens living on the open and undulating plains, at the distance of many miles from a tree. I was confirmed in my belief, that these birds do not frequent trees, by the beaks of some which I shot being muddy, by their tails being but little abraded, and by their alighting on posts or branches of trees (where such grew) horizontally and crosswise, in the manner of ordinary birds, though, as I have stated, they sometimes alighted vertically. When I wrote these notes, I knew nothing of the works of Azara, who lived for many years in Paraguay, and is generally esteemed as an accurate observer. Now Azara2 calls this bird the Woodpecker of the plains, and remarks that the name is highly appropriate; for, as he asserts, it never visits woods, or climbs up trees, or searches for insects under the bark.* He describes its manner of feeding on the open ground, and of alighting, sometimes horizontally and sometimes vertically, on trunks, rocks, &c., exactly as I have done. He states that the legs are longer than those of other species of Woodpeckers. The beak, however, is not so straight and strong, nor the tail-feathers so stiff, as in the typical members of the group. Therefore this species appears to have been to a slight extent modified, in accordance with its less arboreal habits. Azara further states that it builds its nest in holes, excavated in old mud walls or in the banks of streams. I may add that the Colaptes pitius, which in Chile represents the Pampas species, likewise frequents dry stony hills, where only a few bushes or trees grow, and may be continually seen feeding on the ground. According to Molina, this Colaptes also builds its nest in holes and banks. |706| Mr. Hudson, on the other hand, states that near Buenos Ayres, where there are some woods, the Colaptes campestris climbs trees and bores into the bark like other Woodpeckers. He says, “it is sometimes found several miles distant from any trees. This, however, is rare, and it is on such occasions always apparently on its way to some tree in the distance. It here builds its nest in holes in trees.” I have not the least doubt that Mr. Hudson’s account is perfectly accurate, and that I have committed an error in stating that this species never climbs trees. But is it not possible that this bird may have somewhat different habits in different districts, and that I may not be quite so inaccurate as Mr. Hudson supposes? I cannot doubt, from what I saw in Banda Oriental, that this species there habitually frequents the open plains, and lives exclusively on the food thus obtained. Still less can I doubt the account given by Azara of its general habits of life, and of its manner of nidification.3 Finally, I trust that Mr. Hudson is mistaken when he says that any one acquainted with the habits of this bird might be induced to believe that I “had purposely wrested the truth in order to prove” my theory. He exonerates me from this charge; but I should be loath to think that there are many naturalists who, without any evidence, would accuse a fellow worker of telling a deliberate falsehood to prove his theory. *

Apunt. ii. p. 311 (1802).

1871. [Two letters to C. Boner]

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3

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William Henry Hudson (1841–1922), ornithologist and popular writer. Hudson 1870. CD noted in his Banda Oriental notebook, p. [6] on 15 November 1833 ‘woodpecker nest in hole’ Chancellor and van Wyhe, Beagle notebooks; see also Zoology notes, p. 154, and Steinheimer 2004, appendix, p. 17. CD referred to ground living woodpeckers in Origin pp. 184, 186, 204 and 471. CD first added the name Colaptes campestris to the 3d ed. of Origin, (1861) p. 202. The campo flicker nests both in mud banks and holes in trees (Winkler et al. 1995, p. 326). Nest making.

1871. [Two letters to C. Boner]. In Kettle, R. M. ed., Memoirs and letters of Charles Boner, author of “Chamois hunting in Bavaria,” &c. London: Richard Bentley and son, vol. 1: 76–8. F1950 I have just received your two works,1 and have made some use of them for my present book;2 and I should have made more use of them had I received them earlier. You describe the grand scenery of the Tyrol most graphically, and it makes me long to be strong and young again to ramble over the mountains. My next book will not be ready for a considerable time, though part is finished. I am very much obliged to you for your very interesting letter, and especially glad to hear about the co-existence of varieties in the wild state. The fact relating to the variation of the wild boar is quite new to me. I hope I shall get your book soon, and with my best thanks, I remain, dear sir, &c, Charles Darwin. My Dear Sir, I am very much obliged for your extremely kind note and the really valuable present of your work on Transylvania.3 I do not think I ever read a word about that country, and I am ashamed to confess that I had to look at a map |78| to be sure where it lay. Therefore, as soon as I have finished some books which I have in hand, I will begin your volume. You must, indeed, feel most acutely your present state of health, which I am truly sorry to hear of. My own health has been failing for so many years that I can hardly imagine the sense of vigour and the power of endurance. I must be content to enjoy the glorious scenes of nature, as described by you and others. With every hope that you may perfectly recover your health and observe the habits of wild animals again, I beg leave to remain, yours, &c., &c., Charles Darwin.

1 2 3

Charles Boner (1815–70), writer who lived most of his adult life in Germany. Boner 1860 and Boner 1861. CD cited Boner’s works in Descent 2: 245, 253, 259 and 269. Boner 1865.

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1871. Pangenesis

1871. Pangenesis. Nature 3 (27 April): 502–3. F1751 In a paper, read March 30, 1871, before the Royal Society, and just published in the Proceedings,1 Mr. Galton2 gives the results of his interesting experiments on the intertransfusion of the blood of distinct varieties of rabbits. These experiments were undertaken to test whether there was any truth in my provisional hypothesis of Pangenesis.3 Mr. Galton, in recapitulating “the cardinal points,” says that the gemmules are supposed “to swarm in the blood.” He enlarges on this head, and remarks, “Under Mr. Darwin’s theory, the gemmules in each individual must, therefore, be looked upon as entozoa of his blood,” &c. Now, in the chapter on Pangenesis in my “Variation of Animals and Plants under Domestication,” I have not said one word about the blood, or about any fluid proper to any circulating system. It is, indeed, obvious that the presence of gemmules in the blood can form no necessary part of my hypothesis; for I refer in illustration of it to the lowest animals, such as the Protozoa, which do not possess blood or any vessels; and I refer to plants in which the fluid, when present in the vessels, cannot be considered as true blood. The fundamental laws of growth, reproduction, inheritance, &c., are so closely similar throughout the whole organic kingdom, that the means by which the gemmules (assuming for the moment their existence) are diffused through the body, would probably be the same in all beings; therefore the means can hardly be diffusion through the blood. Nevertheless, when I first heard of Mr. Galton’s experiments, I did not sufficiently reflect on the subject, and saw not the difficulty of believing in the presence of gemmules in the blood. I have said (Variation, &c., vol. ii., p. 379) that “the gemmules in each organism must be thoroughly diffused; nor does this seem improbable, considering their minuteness, and the steady circulation of fluids throughout the body.” But when I used these latter words and other similar ones, I presume that I was thinking of the diffusion of the gemmules through the tissues, or from cell to cell, independently of the presence of vessels,—as in the remarkable experiments by Dr. Bence Jones,4 in which chemical elements absorbed by the stomach were detected in the course of some minutes in the crystalline lens of the eye; or again as in the repeated loss of colour and its recovery after a few days by the hair, in the singular case of a neuralgic lady recorded by Mr. Paget.5 Nor can it be objected that the gemmules could not pass through tissues or cell-walls, for the contents of each pollen-grain have to pass through the coats, both of the pollen-tube and embryonic sack. I may add, with respect to the passage of fluids through membrane, that they pass from cell to cell in the absorbing hairs of the roots of living plants at a rate, as I have myself observed under the microscope, which is truly surprising. When, therefore, Mr. Galton concludes from the fact that rabbits of one variety, with a large proportion of the blood of another variety in their veins, do not produce mongrelised offspring, that the hypothesis of Pangenesis is false, it seems to me that his conclusion is a little hasty. His words are, “I have now made experiments of transfusion |503| and cross circulation on a large scale in rabbits, and have arrived at definite results, negativing, in my opinion, beyond all doubt the truth of the doctrine of Pangenesis.” If Mr. Galton could have proved that the reproductive elements were contained in the blood of the higher

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animals, and were merely separated or collected by the reproductive glands, he would have made a most important physiological discovery. As it is, I think every one will admit that his experiments are extremely curious, and that he deserves the highest credit for his ingenuity and perseverance. But it does not appear to me that Pangenesis has, as yet, received its death blow; though, from presenting so many vulnerable points, its life is always in jeopardy; and this is my excuse for having said a few words in its defence. Charles Darwin6

1 2 3 4 5

6

Galton 1871. Francis Galton (1822–1911), traveller, statistician, scientific writer and founder of the eugenics movement and CD’s half-first cousin. First published in Variation 2, chapter 27. Henry Bence Jones (1814–73), physician, chemist and CD’s personal physician for twenty years. Bence Jones 1865a and 1865b. James Paget (1814–99), surgeon. Paget 1853, 1: 46, states: A lady who is subject to attacks of what are called nervous headaches, always finds next morning that some patches of her hair are white, as if powdered with starch. The change is effected in a night; and in a few days after, the hairs gradually regain their dark brownish colour. CD cited this case again in Variation 2d ed., 2: 374. Galton replied in Galton 1871b.

1871. [Letter to C. L. Balch of the New York Liberal Club]. A letter from Mr. Darwin. New York World (8 May). F1981 The great English naturalist and philosopher has addressed the following note to the corresponding secretary of the Liberal Club: Down Beckenham, Kent, S.E., April 15, 1871. To Professor Charles L. Balch, Corresponding Secretary New York Liberal Club.1 Dear Sir: I am much obliged for your extremely kind note and for the report of your lecture which you have been good enough to send. I am aware that I have but few supporters in your country. Should the Liberal Club do me the honor of electing me an honorary member I shall feel much flattered. Would you be so good as to say to Mr. McDonald2 that I enclose four photographs for his acceptance: but I should fear that it could never be worth his while to execute a bust of me. Pray believe me, dear sir, yours faithfully, Ch. Darwin.

1

Possibly Charles Leland Balch (1840–72), of New York. Balch replied to CD, see Cal: 7408. No subsequent correspondence between the two has been found. The New York Liberal Club was established in 1869. CD was elected an Honorary Member in 1871. See later correspondence

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with the Liberal Club Cal: 9600 and 9601. This letter prompted correspondence from F. E. Abbot (see Darwin, 1871, F1753 (below)) who felt CD’s assertion that he had ‘but few supporters’ in the USA would entail ‘a sad proof of American ignorance and unintelligence’. Abbot to CD 11 May 1871 DAR159.1 James Wilson Alexander MacDonald (1824–1908), American painter and sculptor who planned to make a bust of CD.

1871. A letter from Mr. Darwin. The Index, a weekly paper devoted to free religion 2 no. 51 (23 December): 404. F1753 In our issue of June 24, of the present year, the following passage was contained in an editorial article: —1 “Only yesterday we received from one of the greatest scientific men of England, whose name is famous throughout the entire civilized world, a private letter of which the following was the closing sentence:—‘I have now read ‘Truths for the Times,’ and I admire them from my inmost heart; and I believe that I agree to every word.’”2

We are now authorized by kind permission of the writer to say that the above extract is from a letter written by Mr. Charles Darwin. In another letter dated Nov. 16, Mr. Darwin says: — “I have read again ‘Truths for the Times,’ and abide by my words as strictly true. If you still think fit to publish them, you had better perhaps omit ‘I believe,’ and add ‘almost’ to ‘every word,’ so that it will run—‘and I agree to almost every word.’ The points on which I doubtfully differ are unimportant; but it is better to be accurate. I should be much obliged if you would somehow prefer to word as an extract from a letter not originally intended for publication, or to this effect; as it seems to be somewhat conceited or arrogant otherwise to express my assent.”

1

Written by Francis Ellingwood Abbot (1836–1903), American Unitarian minister, liberal religious philosopher, writer, co-founder of the Free Religious Association (1867) and editor of its Toledo Ohio newspaper The Index (1870–80). Truths for the times (Abbot 1872) was a pamphlet which, as Abbot described in this article, ‘is an effort to bring the truest science and the truest religion of the age into absolute harmony and mutual understanding. The supposed conflict between science and religion is superficial and unreal, when both are properly conceived.’ CD’s endorsement for Truths for the times was published in The Index from 1871–80 when CD asked his son William to write to Abbot, who was no longer to edit the journal, to discontinue printing the endorsement in future (Cal: 12633). See LL1: 304–6 and Browne 2002, pp. 391–2. 2 The quotation from CD’s letter appeared in Darwin 1871, F1753a. The editorial article was entitled ‘The Index Association’.

1871. A new view of Darwinism. Nature 4 (6 July): 180–1. F1754 I am much obliged to Mr. Howorth1 for his courteous expressions towards me in the letter in your last number. If he will be |181| so good as to look at p. 111 and p. 148, vol. ii. of my

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“Variation of Animals and Plants under Domestication,” he will find a good many facts and a discussion on the fertility and sterility of organisms from increased food and other causes. He will see my reasons for disagreeing with Mr. Doubleday,2 whose work I carefully read many years ago. Charles Darwin Down, Beckenham, Kent, July, 1

1 2

Henry Hoyle Howorth (1842–1923), geologist and naturalist. Howorth 1871a. Henry Doubleday (1808–75), entomologist, ornithologist and Quaker. Doubleday 1842.

1871. Fertilisation of Leschenaultia. Gardeners’ Chronicle and Agricultural Gazette no. 36 (9 September): 1166. F1755 As “F. W. B.”1 inquires, in your number of August 26, about the seeding of Leschenaultia, I will give my small experience. During 1860 and 1862, I was led to make some observations on the fertilisation of L. formosa and biloba, from having read that with these flowers self-fertilisation [= self-pollination] was an inevitable contingency; and this, from what I had seen during many years, seemed to me highly improbable. I found, as “F. W. B.” states, that before the flower expands, the anthers open and the pollen is shed. This occurs in a considerable number of plants, as in most Leguminosae, Fumariaceae, &c.; but it can be clearly shown that this by no means necessarily leads to self-fertilisation. In Leschenaultia the pollen, when shed, is neatly collected in a cup-shaped indusium, the mouth of which is at first widely open, but soon closes. Thus far I can follow “F. W. B.;” but he will, I think, find, on further examination, that the pollen must, in order that the flower should be fertilised, be subsequently removed from the indusium, and then placed on an exterior stigmatic surface. This no doubt is effected by insects, tempted to visit the flowers by the copious supply of nectar. On the outside of the indusium there is a viscid surface, and when on two occasions I placed some pollen-grains on the surface, I found, after an interval of about 20 hours, that it was deeply penetrated by numerous pollen-tubes. I was so much surprised at this position of the stigma, that I asked Dr. Hooker to dissect some flowers, which he did with care, and he confirmed my conclusion with respect to L. formosa. He also examined two other species, and found no trace of a stigma within the indusium. I should here add that Mr. Bentham has subsequently described the structure of the parts in this genus, but I cannot at the present moment lay my hand on his paper.2 When the flower is fully expanded the lips of the indusium fit closely, and cannot be very easily opened. If, however, a finely-pointed, small camel-hair brush be held parallel to the pistil, and be gently inserted into the flower, so as to imitate the entry of an insect, the

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tip of the brush, by pressing against the slightly projecting lower lip of the indusium, opens it; and some of the hairs enter and become smeared with pollen. If the same brush be now successively inserted into several flowers, pollen-grains will be found left on the exterior viscid stigma. During the early part of the summer I treated in this manner several flowers, but with no result. Towards the end of July, however, five flowers were thus treated, and the germens of all soon became much enlarged. Two of them, after a time, shanked off, but three remained on till the autumn, and each contained about 25 seeds. My plant produced hundreds of flowers during two or three summers, but the germens of none spontaneously swelled, with the exception of two growing close together, which I imagined had been visited by some insect. These two produced some seeds, but fewer in number than in the above case. All the seeds were in external appearance good, but when sown they did not germinate. The flowers were necessarily fertilised with pollen from the same plant, but it would have been incomparably better if pollen from a distinct seedling plant could have been employed. This would have been all the more advisable, as the late Mr. Drummond,3 of Swan River, in Australia, to whom I wrote, asking him to observe in the proper season what insects visited the Leschenaultias, informed me that the species growing there in a state of Nature very rarely produce seed. It appears at first sight a surprising circumstance that in this genus and in some allied genera, the pollen, whilst the flowers are still in bud, should be scooped out of the anthers, in which it might have remained ready for use, and then be immediately enclosed in a specially contrived receptacle, from which it has afterwards to be removed, so as to be placed on the stigma. But he who believes in the principle of gradual evolution, and looks at each structure as the summing up of a long series of adaptations to past and changing conditions— each successive modification being retained as far as that is possible through the force of inheritance—will not feel surprise at the above complex and apparently superfluous arrangement, or the other still more complex arrangements, though they may all serve for one and the same general purpose. Any one desiring to learn how diversified are the means for preventing self-fertilisation, even within the limits of the same family of plants, should study Mr. Bentham’s short but extremely curious paper, just published (in the Journal of the Linnean Society), on the styles of the Australian Proteaceae.4 I cannot resist specifying one of the remarkable contrivances described by Mr. Bentham. In Synaphea the upper anther does not subserve its proper function of producing pollen, but has been converted into a short broad strap, firmly fixed to the edge of the stigmatic disc. By this means the stigma is held in such a position that it cannot receive pollen from the fertile anthers of the same flower; or, as Mr. Bentham puts the case, “the stigma thus held by the eunuch (i. e., the barren anther) is safe from all pollution from her brother anthers, and is preserved intact from any pollen that may be inserted * * by insects or other agencies.”5 Charles Darwin. (In order to render this matter more clear we reproduce the woodcut from p. 1103 Eds.)

1872. Bree on Darwinism.

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F. W. B. 1871. George Bentham (1800–84), botanist. Bentham 1869. James Drummond. Bentham 1871. CD also cited Bentham in Cross fertilisation p. 412. The name of the journal was inserted by the editor of the Gardeners’ Chronicle. Ibid., p. 64 reads ‘intact for any pollen’ rather than ‘from any pollen’.

1872. [Memorial to Gladstone] Mr. Ayrton and Dr. Hooker. Nature 6 (11 July): 211–16. F19371

1

CD signed this memorial along with ten others on behalf of J. D. Hooker. At issue was an ongoing dispute over authority and interference from Acton Smee Ayrton (1816–86), barrister and MP, who served in Gladstone’s cabinet as First Commissioner of Works, 1868–74. William Ewart Gladstone (1809–98), Chancellor of the Exchequer, 1852–55 and 1859–66; Prime Minister, 1868–74. See also Darwin 1874, F1954 (p. 386). This c. 8000 word item is omitted here for lack of space.

1872. Bree on Darwinism. Nature 6 (8 August): 279. F1756 Permit me to state—though the statement is almost superfluous—that Mr. Wallace, in his review of Dr. Bree’s work,1 gives with perfect correctness what I intended to express, and what I believe was expressed clearly, with respect to the probable position of man in the

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early part of his pedigree. As I have not seen Dr. Bree’s recent work, and as his letter is unintelligible to me, I cannot even conjecture how he has so completely mistaken my meaning: but, perhaps, no one who has read Mr. Wallace’s article, or who has read a work formerly published by Dr. Bree on the same subject as his recent one, will be surprised at any amount of misunderstanding on his part. Charles Darwin August 3

1

Wallace 1872. Charles Robert Bree (1811–86), physician, zoologist and anti-Darwinian. Bree 1872. See LL3: 167. Entomologist Raphael Meldola (1849–1915) also replied to Bree in a letter following CD’s. (DO)

1873. Natural selection. Spectator 46 (18 January): 76. F1758 Sir,—Any one interested in the subject to which you allude at p. 42 of your last number,1 namely, the relative importance in causing modifications of the body or mind, on the one hand of habit or of the direct action of external conditions, and on the other hand of natural or artificial selection, will find this subject briefly discussed in the second volume (pp. 301–315) of my “Variation of Animals and Plants under Domestication.” I have there given a considerable body of facts, chiefly in relation to acclimatisation, which presents the greatest difficulty in the present question; and it may be inferred from these facts, firstly, that variations of a directly opposite nature, which would be liable either to preservation or elimination through natural selection, not rarely arise in organisms long exposed to similar conditions; and secondly, that habit, independently of selection, has often produced a marked effect. But it is most difficult, as I have insisted in many of my works, though in some cases possible, to discriminate between the results of the two processes. Both tend to concur, for the individuals which inherit in the strongest manner any useful habit will commonly be preserved. Take, as an instance, the fur of quadrupeds, which grows thickest in the individuals living far north; now there is reason to believe that weather acts directly on the skin with its appendages, but it is extremely difficult to judge how much of the effect ought to be attributed to the direct action of a low temperature, and how much to the best protected individuals of many generations having survived during the severest winters. I have made many observations and collected many facts, showing the potent influence of habit and of the use or disuse of parts on organic beings; but there are numberless peculiarities of structure and of instinct (as in the case of sterile neuter insects) which cannot be thus accounted for. He would be a bold man who would attempt to explain by these means the origin of the exsertile claws and great canine teeth of the tiger; or of the horny lamellae on the beak of the duck, which are so well adapted for sifting water. Nor would anyone, I presume, even attempt to explain the development, for instance, of the beautifully plumed seeds of the dandelion, or of the endless contrivances which are necessary for the

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fertilisation of very many flowers by insects, through gradually acquired and inherited habit, or through the direct action of the external conditions of life.—I am, Sir, &c., Charles Darwin. Down, Beckenham, Kent, Jan. 11, 1873.

1

Anon 1873a.

1873. Inherited instinct. Nature 7 (13 February): 281. F1757 The following letter seems to me so valuable, and the accuracy of the statements vouched for by so high an authority, that I have obtained permission from Dr. Huggins to send it for publication.1 No one who has attended to animals either in a state of nature or domestication will doubt that many special fears, tastes, &c., which must have been acquired at a remote period, are now strictly inherited. This has been clearly proved to be the case by Mr. Spalding with chickens and turkeys just born, in his admirable article recently published in Macmillan’s Magazine.2 It is probable that most inherited or instinctive feelings were originally acquired by slow degrees through habit and the experience of their utility; for instance the fear of man, which as I showed many years ago, is gained very slowly by birds on oceanic islands. It is, however, almost certain that many of the most wonderful instincts have been acquired independently of habit, through the preservation of useful variations of pre-existing instincts. Other instincts may have arisen suddenly in an individual and then been transmitted to its offspring, independently both of selection and serviceable experience, though subsequently strengthened by habit. The tumbler-pigeon is a case in point, for no one would have thought of teaching a pigeon to turn head over heels in the air; and until some bird exhibited a tendency in this direction, there could have been no selection. In the following case we see a specialised feeling of antipathy transmitted through three generations of dogs, as well as to some collateral members of the same family, and which must have been acquired within a very recent period. Unfortunately it is not known how the feeling first arose in the grandfather of Dr. Huggins’s dog. We may suspect that it was due to some ill-treatment; but it may have originated without any assignable cause, as with certain animals in the Zoological Gardens, which, as I am assured by Mr. Bartlett,3 have taken a strong hatred to him and others without any provocation. As far as it can be ascertained, the great-grandfather of Dr. Huggins’s dog did not evince the feeling of antipathy, described in the following letter. Charles Darwin

1

William Huggins (1824–1910), astronomer, his letter, here omitted (DO), gives an account of three generations of dogs which exhibited fright when in the vicinity of a butcher or butcher’s shop. Further letters on the subject appeared in Nature (20 February 1873): 303 and (20 March 1873): 377–8.

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Douglas Alexander Spalding (1841–77), comparative psychologist. Spalding 1873. Abraham Dee Bartlett (1812–97), superintendent of the Zoological Society’s Gardens, Regent’s Park, London.

[1873]. Testimonials in favour of W. Boyd Dawkins, M. A., F. R. S., F. G. S. a candidate for the Woodwardian Professorship of Geology. Cambridge: University Press printed, p. [2]. F1216 Down, Beckenham, Kent, February 3, 1873. My Dear Sir,1 I have great pleasure in expressing my opinion that you are very well fitted to fill the Woodwardian Chair in Cambridge, now vacant by the death of its former venerated occupier.2 You have paid close attention to the geological history of the more recent periods, and I think every one will admit that these present an extraordinary amount of difficulty; so that your success in this line of research offers an excellent test of your ability. It will also, I think, be admitted that the study of the more recent periods is not only very difficult, but of the highest importance. Therefore I earnestly hope that you may be successful in your application, and if so, I do not doubt that you will be the means of encouraging the study of geology in the University. Believe me, my dear Sir, Yours sincerely, Ch. Darwin. To W. Boyd Dawkins, Esq., F. R. S.

1

2

William Boyd Dawkins (1837–1929), geologist and palaeontologist. He was appointed to the Chair of Geology at Owens College, Manchester, in 1872. His application for the Cambridge chair was unsuccessful. Adam Sedgwick.

1873. Perception in the lower animals. Nature 7 (13 March): 360. F1759 As several persons seem interested in Mr. Wallace’s1 suggestion that animals find their way home by recognising the odour of the places which they have passed whilst shut up, you may perhaps think the following little fact worth giving. Many years ago I was on a mail-coach, and as soon as we came to a public-house, the coachman pulled up for the fraction of a second. He did so when we came to a second public-house, and I then asked him the reason. He pointed to the off-hand wheeler,2 and said that she had been long completely blind, and she would stop at every place on the road at which she had before stopped. He had found by experience that less time was wasted by pulling up his team than by trying to drive her past the place, for she was contented with a momentary stop. After this I watched her,

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and it was evident that she knew exactly, before the coachman began to pull up the other horses, every public-house on the road, for she had at some time stopped at all. I think there can be little doubt that this mare recognised all these houses by her sense of smell. With respect to cats, so many cases have been recorded of their returning from a considerable distance to their homes, after having been carried away shut up in baskets, that I can hardly disbelieve them, though these stories are disbelieved by some persons. Now, as far as I have observed, cats do not possess a very acute sense of smell, and they seem to discover their prey by eyesight and by hearing. This leads me to mention another trifling fact: I sent a riding-horse3 by railway from Kent viâ Yarmouth, to Freshwater Bay, in the Isle of Wight. On the first day that I rode eastward, my horse, when I turned to go home, was very unwilling to return towards his stable, and he several times turned round. This led me to make repeated trials, and every time that I slackened the reins, he turned sharply round and began to trot to the eastward by a little north, which was nearly in the direction of his home in Kent. I had ridden this horse daily for several years, and he had never before behaved in this manner. My impression was that he somehow knew the direction whence he had been brought. I should state that the last stage from Yarmouth to Freshwater is almost due south, and along this road he had been ridden by my groom; but he never once showed any wish to return in this direction. I had purchased this horse several years before from a gentleman in my own neighbourhood, who had possessed him for a considerable time. Nevertheless it is possible, though far from probable, that the horse may have been born in the Isle of Wight. Even if we grant to animals a sense of the points of the compass, of which there is no evidence, how can we account, for instance, for the turtles which formerly congregated in multitudes, only at one season of the year, on the shores of the Isle of Ascension, finding their way to that speck of land in the midst of the great Atlantic Ocean? Charles Darwin

1 2 3

Wallace 1873. The horse on the far side from the driver, nearest the wheels. The horse was known as Tommy. See LL1: 117–18, 3: 222, ‘Sketches for a biography’ by Henrietta Litchfield (nd). DAR262.23.1 (DO) and Freeman 2007.

1873. Origin of certain instincts. Nature 7 (3 April): 417–8. F1760 The writer of the interesting article in Nature of March 20 doubts whether my belief “that many of the most wonderful instincts have been acquired, independently of habit, through the preservation of useful variations of pre existing instincts,” means more than “that in a great many instances we cannot conceive how the instincts originated.”1 This in one sense is perfectly true, but what I wished to bring prominently forward was simply that in certain cases instincts had not been acquired through the experience of their utility, with continued practice during successive generations. I had in my mind the case of neuter insects, which never leave offspring to inherit the teachings of experience, and which are themselves the

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offspring of parents which possess quite different instincts. The Hive-bee is the best known instance, as neither the queen nor the drones construct cells, secrete wax, collect honey, &c. If this had been the sole case, it might have been maintained that the queens, like the fertile females of humble-bees, had in former ages worked like the present neuters, and had thus gradually acquired these instincts; and that they had ever afterwards transmitted them to their sterile offspring, though they themselves no longer practised such instincts. But there are several species of Hive-bees (Apis) of which the sterile workers have somewhat different habits and instincts, as shown by their combs. There are also many species of ants, the fertile females of which are believed not themselves to work, but to be served by the neuters, which capture and drag them to their nests; and the instincts of the neuters in the different species of the same genus are often different. All who believe in the principle of evolution will admit that with social insects the closely allied species of the same genus are descended from a single parent-form; and yet the sterile workers of the several species have somehow acquired different instincts. This case appeared to me so remarkable that I discussed it at some length in my “Origin of Species;”2 but I do not expect that anyone who has less faith in natural selection than I have, will admit the explanation there given. Although he may explain in some other way, or leave unexplained, the development of the wondrous instincts possessed by the various sterile workers, he will, I think, be compelled to admit that they cannot have been acquired by the experience of one generation having been transmitted to a succeeding one. I should indeed be glad if anyone could show that there was some fallacy in this reasoning. It may be added that the possession of highly complex instincts, though not derived through conscious experience, does not at all preclude insects bringing into play their individual sagacity in modifying their work under new or peculiar circumstances; but such sagacity, as far as inheritance is concerned, as well as their instincts, can be modified or injured only by advantage being taken of variation in the minute brain of their parents, probably of their mothers. The acquirement or development of certain reflex actions, in which muscles that cannot be influenced by the will are acted on, is a somewhat analogous case to that of the above class of instincts, as I have shown in my recently published book on Expression; for consciousness, on which the sense of utility depends, cannot have come into play in the case of actions effected by involuntary muscles.3 The beautifully adapted movements of the iris, when the retina is stimulated by too much or too little light, is a case in point. The writer of the article in referring to my words “the preservation of useful variations of pre-existing instincts” adds “the question is, whence these variations?” Nothing is more to be desired in natural history than that some one should be able to answer such a query.4 But as far as our present subject is concerned, the writer probably will admit that a multitude of variations have arisen, for instance in colour and in the character of the hair, feathers, horns, &c, which are quite independent of habit and of use in previous generations. It seems far from wonderful, considering the complex conditions to which the whole organisation is exposed during the successive stages of its development from the germ, that every part should be liable to occasional modifications: the wonder indeed is that any two individuals of the same species are at all closely alike. If this be admitted, why should not the brain, as

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well as all other parts of the body, sometimes vary in a slight degree, independently of useful experience and habit? Those physiologists, and there are many, who believe that a new mental characteristic cannot be transmitted to the child except through some modification of that material sub-stratum which proceeds from the parents, and from which the brain of the child is ultimately developed, will not doubt that any cause which affects its development may, and often will, modify the transmitted mental characters. With species in a state of nature such modifications or variations would commonly lead to the partial or complete loss of an instinct, or to its perversion; and the individual would suffer. But if under the then existing conditions any such mental variation was serviceable, it would be preserved and fixed, and would ultimately become common to all the members of the species. The writer of the article also takes up the case of the tumbling of the pigeon, which habit, if seen in a wild bird, would certainly have been called instinctive; more especially if, as has been asserted, it aids these birds in escaping from hawks. He suggests that it “is a fancy instinct, an outlet for the overflowing activity of a creature whose wants are all provided for without any exertion on its part;” but even on this supposition there must have been some physical cause which induced the first tumbler to spend its overflowing activity in a manner unlike that of any other bird in the world. The behaviour of the ground-tumbler or Lotan of India, renders it highly probable that in this sub-breed the tumbling is due to some affection of the brain, which has been transmitted from before the year 1600 to the present day. It is necessary gently to shake these birds, or in the case of the Kalmi Lotan, to touch them on the neck with a wand, in order to make them begin rolling over backwards on the ground. This they continue to do with extraordinary rapidity, until they are utterly exhausted, or even, as some say, until they die, unless they are taken up, held in the hands, and |418| soothed; and then they recover. It is well-known that certain lesions of the brain, or internal parasites, cause animals to turn incessantly round and round, either to the right or left, sometimes accompanied by a backward movement: and I have just read, through the kindness of Dr. Brunton,5 the account given by Mr. W. J. Moore (Indian Medical Gazette, Jan. and Feb. 1873)6 of the somewhat analogous result which followed from pricking the base of the brain of a pigeon with a needle. Birds thus treated roll over backwards in convulsions, in exactly the same manner as do the ground-tumblers; and the same effect is produced by giving them hydrocyanic acid with strychnine. One pigeon which had its brain thus pricked recovered perfectly, but continued ever afterwards to perform summersaults like a tumbler, though not belonging to any tumbling breed. The movement appears to be of the nature of a recurrent spasm or convulsion which throws the bird backwards, as in tetanus; it then recovers its balance, and is again thrown backwards. Whether this tendency originated from some accidental injury, or, as seems more probable, from some morbid affection of the brain, cannot be told; but at the present time the affection can hardly be called morbid in the case of common tumblers, as these birds are perfectly healthy and seem to enjoy performing their feats, or, as an old writer expresses it, “showing like footballs in the air.”7 The habit apparently can be controlled to a certain extent by the will. But what more particularly concerns us is that it is strictly inherited. Young birds reared in an aviary which have never seen a pigeon tumble, take to it when first let free. The habit also varies much in degree

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in different individuals and in different sub-breeds; and it can be greatly augmented by continued selection, as seen in the house-tumblers, which can hardly rise more than a foot or two above the ground without going head over heels in the air. Fuller details on tumbler-pigeons, may be found in my “Variation of Animals under Domestication,” vol. i. pp. 150, 209. In conclusion, from the case of neuter insects, of certain reflex actions, and of movements such as those of the tumbler-pigeon, it seems to me in the highest degree probable that many instincts have originated from modifications or variations in the brain, which we in our ignorance most improperly call spontaneous or accidental; such variations having led, independently of experience and of habit, to changes in pre-existing instincts, or to quite new instincts, and these proving of service to the species, have been preserved and fixed, being, however, often strengthened or improved by subsequent habit. With regard to the question of the means by which animals find their way home from a long distance, a striking account, in relation to man, will be found in the English translation of the Expedition to North Siberia, by Von Wrangell.8 He there describes the wonderful manner in which the natives kept a true course towards a particular spot, whilst passing for a long distance through hummocky ice, with incessant changes of direction, and with no guide in the heavens or on the frozen sea. He states (but I quote only from memory of many years standing) that he, an experienced surveyor, and using a compass, failed to do that which these savages easily effected. Yet no one will suppose that they possessed any special sense which is quite absent in us. We must bear in mind that neither a compass, nor the north star, nor any other such sign, suffices to guide a man to a particular spot through an intricate country, or through hummocky ice, when many deviations from a straight course are inevitable, unless the deviations are allowed for, or a sort of “dead reckoning” is kept. All men are able to do this in a greater or less degree, and the natives of Siberia apparently to a wonderful extent, though probably in an unconscious manner. This is effected chiefly, no doubt, by eyesight, but partly, perhaps, by the sense of muscular movement, in the same manner as a man with his eyes blinded can proceed (and some men much better than others) for a short distance in a nearly straight line, or turn at right angles, or back again. The manner in which the sense of direction is sometimes suddenly disarranged in very old and feeble persons, and the feeling of strong distress which, as I know, has been experienced by persons when they have suddenly found out that they have been proceeding in a wholly unexpected and wrong direction, leads to the suspicion that some part of the brain is specialised for the function of direction.9 Whether animals may not possess the faculty of keeping a dead reckoning of their course in a much more perfect degree than can man; or whether this faculty may not come into play on the commencement of a journey when an animal is shut up in a basket, I will not attempt to discuss, as I have not sufficient data. I am tempted to add one other case, but here again I am forced to quote from memory, as I have not my books at hand. Audubon kept a pinioned wild goose in confinement, and when the period of migration arrived, it became extremely restless, like all other migratory birds under similar circumstances; and at last it escaped. The poor creature then immediately began its long journey on foot, but its sense of direction seemed to have been

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perverted, for instead of travelling due southward, it proceeded in exactly the wrong direction, due northward.10 Charles Darwin

1 2 3 4 5 6

7

8 9 10

Anon 1873b. The writer referred to Darwin 1873, F1757 (p. 374). Origin pp. 235–42. Expression pp. 35–42. See CD’s treatment of the origins of variations in Variation 2: 430–1. Thomas Lauder Brunton (1844–1916), physician and consultant at St. Bartholomew’s Hospital, London from 1871. William James Moore (1828–96), Surgeon-General to the Government of Bombay. See CD’s abstract of this article in DAR45.181. (DO) CD cited Moore’s note in the Indian Medical Gazette (January–February 1873): 35 in Variation 2d ed., 1: 228. Francis Willughby (1635–72), pioneering ornithologist and ichthyologist. Ray 1687, p. 282: ‘10. Tumblers, these are small, and of divers colours. They have strange motions, turning themselves backward over their Heads, and shew like footbals in the Air.’ Also quoted in Variation 1: 209 as ‘which show like footballs in the air’. Sabine 1840, p. 146. Compare with Darwin 1861, F1961 (p. 306) note 3 on phrenology. John James Audubon (1785–1851), American ornithologist and illustrator. Audubon 1831–39. CD cited the same story in Natural selection pp. 492, 494, Darwin 1883, p. 359 and Descent 2d ed. (1882) p. 105.

1873. Instinct: Perception in ants. Nature 7 (10 April): 443–4. F1810 The following fact with respect to the habits of ants, which I believe to be quite new, has been sent to me by a distinguished geologist, Mr. J. D. Hague;1 and it appears well worth publishing.2 Charles Darwin

1 2

James Duncan Hague (1836–1908), American mining engineer; he later published a recollection of an 1871 meeting with CD in Hague 1884. Hague’s letter gave an account of ants that showed distress when approaching and later avoided the spot where their kindred had been crushed by a finger.

1873. Habits of ants. Nature 8 (24 July): 244. F1761 Some months ago (vol. vii. p. 443) I sent you an extract from a letter from Mr. Hague, a geologist residing in California, who gave me a very curious account of the terrifying effect on the other ants of the sight of a few which he had killed on one of their paths.1 Mr. Traherne Moggridge2 saw this account in Nature, and wrote to me that he had heard from a gentleman who had lived in Australia that merely drawing a finger across the path deters ants from crossing the line.

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Mr. Moggridge tried this experiment with some ants at Mentone with similar effects. I therefore sent the letter to Mr. Hague, and asked him to observe whether his ants were alarmed by the smell left by the finger, or were really terrified by the sight of their dead and dying comrades. The case appears curious, as I believe no one has ever observed an invertebrate animal realising danger by seeing the corpses of a fellow species. It is indeed very doubtful whether the higher animals can draw any such inferences from the sight; but I believe that everyone who has had experience in trapping animals is convinced that individuals who have never been caught learn that a trap is dangerous by seeing others caught. Here follows Mr. Hague’s letter, fully confirming his former statement.3 Charles Darwin

1 2 3

CD refers to Hague 1873. John Traherne Moggridge (1842–74), naturalist who lived in the South of France because of his tuberculosis. Hague’s letter gave an account of ants that avoided a spot touched by a finger and reacted with fear, as in the previous letter above, when detecting the spot where their fellows were crushed with an object rather than a finger.

1873. On the males and complemental males of certain cirripedes, and on rudimentary structures. Nature 8 (25 September): 431–2. F1762 I beg permission to make a few remarks bearing on Prof. Wyville Thomson’s interesting account of the rudimentary males of Scalpellum regium, in your number of August 28th.1 Since I described in 1851,2 the males and complemental males of certain cirripedes, I have been most anxious that some competent naturalist should re-examine them; more especially as a German,3 without apparently having taken the trouble to look at any specimens, has spoken of my description as a fantastic dream. That the males of an animal should be attached to the female, should be very much smaller than, and differ greatly in structure from her, is nothing new or strange. Nevertheless, the difference between the males and the hermaphrodites of Scalpellum vulgare is so great, that when I first roughly dissected the former, even the suspicion that they belonged to the class of cirripedes did not cross my mind. These males are half as large as the head of a small pin; whereas the hermaphrodites are from an inch to an inch and a quarter in length. They consist of little more than a mere sack, containing the male reproductive organs, with rudiments of only four of the valves; there is no mouth or alimentary canal, but there exists a rudimentary thorax with rudimentary cirri, and these apparently serve to protect the orifice of the sack from the intrusion of enemies. The males of Alcippe and Cryptophialus are even more rudimentary; of the seventeen segments which ought to be fully developed, together with their appendages, only three remain, and these are imperfectly developed; the other fourteen segments are represented by a mere slight projection bearing the probosci-formed penis. This latter organ, on the other hand, is so enormously developed in Cryptophialus, that when fully extended

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it must have been between eight and nine times the length of the animal! There is another curious point about these little males, viz., the great difference between those belonging to the several species of the same genus Scalpellum: some are manifestly pedunculated cirripedes, differing by characters which in an independent creature would be considered as of only generic value; whereas others do not offer a single character by which they can be recognised as cirripedes, with the exception of the cast-off prehensile, larval antennæ, preserved by being buried in the natural cement at the point of attachment. But the fact which has interested me most is the existence of what I have called Complemental Males, from their being attached not to females, but to hermaphrodites; the latter having male organs perfect, although not so largely developed as in ordinary cirripedes. We must turn to the vegetable kingdom for anything analogous to this; for, as is well known, certain plants present hermaphrodite and male individuals, the latter aiding in the cross-fertilisation of the former. The males and complemental males in some of the species of three out of the four very distinct genera in which I have described their occurrence, are, as already stated, extremely minute, and, as they cannot feed, are short-lived. They are developed like other cirripedes, from larvæ, furnished with well-developed natatory legs, eyes of great size and complex prehensile antennæ; by these organs they are enabled to find, cling to, and ultimately to become cemented to the hermaphrodite or female. The male larvæ, after casting their skins and being as fully developed as they ever will be, perform their masculine function, and then perish. At the next breeding season they are succeeded by a fresh crop of these annual males. In Scalpellum vulgare I have found as many as ten males attached to the orifice of the sack of a single hermaphrodite; and in Alcippe, fourteen males attached to a single female. He who admits the principle of evolution will naturally inquire why and how these minute rudimentary males, and especially the complemental males, have been developed. It is of course impossible to give any definite answer, but a few remarks may be hazarded on this subject. In my “Variation under Domestication,” I have given reasons for the belief that it is an extremely general, though apparently not quite universal law, that organisms occasionally intercross, and that great benefit is derived therefrom. I have been laboriously experimenting on this subject for the last six or seven years, and I may add, that with plants there cannot be the least doubt that great vigour is thus gained; and the results indicate that the good depends on the crossed individuals having been exposed to slightly different conditions of life. Now as cirripedes are always attached to some object, and as they are commonly hermaphrodites, their intercrossing appears, at first sight, impossible, except by the chance carriage of the spermatic fluid by the currents of the sea, like pollen by the wind; but it is not probable that this can often happen, as the act of impregnationt4 takes place within the well-enclosed sack. As, however, these animals possess a probosci-formed penis capable of great elongation, two closely attached hermaphrodites could reciprocally fertilise each other This, as I have elsewhere proved, does sometimes, perhaps often, actually occur. Hence perhaps it arises, that most cirripedes are attached in clusters. The curious Anelasma, which lives buried in the skin of sharks in the northern seas, is said always to live in pairs. Whilst reflecting how far cirripedes |432| usually adhered to their

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support in clusters, the case of the genus Acasta occurred to me, in which all the species are embedded in sponges, generally at some little distance from each other; I then turned to my description of the animal, and found it stated, that in several of the species the probosciformed penis is “remarkably long;”5 and this I think can hardly be an accidental coincidence. With respect to the habits of the genera which are provided with true males or complemental males:—all the species of Scalpellum, excepting one, are specially modified for attachment to the delicate branches of corallines: the one species of Ibla, about which I know anything, lives attached, generally two or three together, to the peduncle of another cirripede, viz. a Pollicipes: Alcippe and Cryptophialus are embedded in small cavities which they excavate in shells. No doubt in all these cases two or more full-grown individuals might become attached close together to the same support; and this sometimes occurs with Scalpellum vulgare, but the individuals in such groups are apt to be distorted and to have their peduncles twisted. There would be much difficulty in two or more individuals of Alcippe and Cryptophialus living embedded in the same cavity. Moreover, it might well happen that sufficient food would not be brought by the currents of the sea to several individuals of these species living close together. Nevertheless in all these cases it would be a manifest advantage to the species, if two individuals could live and flourish close together, so as occasionally to intercross. Now if certain individuals were reduced in size and transmitted this character, they could readily be attached to the other and larger individuals; and as the process of reduction was continued, the smaller individuals would be enabled to adhere closer and closer to the orifice of the sack, or, as actually occurs with some species of Scalpellum and with Ibla, within the sack of the larger individual; and thus the act of fertilisation would be safely effected. It is generally admitted that a division of physiological labour is an advantage to all organisms; accordingly, a separation of the sexes would be so to cirripedes, that is if this could be effected with full security for the propagation of the species. How in any case a tendency to a separation of the sexes first arises, we do not know; but we can plainly see that if it occurred in the present case, the smaller individuals would almost necessarily become males, as there would be much less expenditure of organic matter in the production of the spermatic fluid than of ova. Indeed with Scalpellum vulgare the whole body of the male is smaller than a single one of the many ova produced by the hermaphrodite. The other and larger individuals would on the same principle either remain hermaphrodites, but with their masculine organs more or less reduced, or would be converted into females. At any rate, whether these views are correct or not, we see at the present time within the genus Scalpellum a graduated series: first on the masculine side, from an animal which is obviously a pedunculated cirripede with well-proportioned valves, to a mere sack enclosing the male organs, either with the merest rudiments of valves, or entirely destitute of them; and secondly on the feminine side, we have either true females, or hermaphrodites with the male organs perfect, yet greatly reduced. With respect to the means by which so many of the most important organs in numerous animals and plants have been greatly reduced in size and rendered rudimentary, or have been quite obliterated, we may attribute much to the inherited effects of the disuse of parts. But this would not apply to certain parts, for instance to the calcareous valves of

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male cirripedes which cannot be said to be actively used. Before I read Mr. Mivart’s6 acute criticisms on this subject, I thought that the principle of the economy of growth would account for the continued reduction and final obliteration of parts; and I still think, that during the earlier periods of reduction the process would be thus greatly aided. But if we consider, for instance, the rudimentary pistils or stamens of many plants, it seems incredible that the reduction and final obliteration of a minute papilla, formed of mere cellular tissue, could be of any service to the species. The following conjectural remarks are made solely in the hope of calling the attention of naturalists to this subject. It is known from the researches of Quetelet7 on the height of man, that the number of individuals who exceed the average height by a given quantity is the same as the number of those who are shorter than the average by the same quantity; so that men may be grouped symmetrically about the average with reference to their height. I may add, to make this clearer, that there exists the same number of men between three and four inches above the average height, as there are below it. So it is with the circumference of their chests; and we may presume that this is the usual law of variation in all the parts of every species under ordinary conditions of life. That almost every part of the body is capable of independent variation we have good reason to believe, for it is this which gives rise to the individual differences characteristic of all species. Now it does not seem improbable that with a species under unfavourable conditions, when, during many generations, or in certain areas, it is pressed for food and exists in scanty numbers, that all or most of its parts should tend to vary in a greater number of individuals towards diminution than towards increment of size; so that the grouping would be no longer symmetrical with reference to the average size of any organ under consideration. In this case the individuals which were born with parts diminished in size and efficiency, on which the welfare of the species depended, would be eliminated; those individuals alone surviving in the long run which possessed such parts of the proper size. But the survival of none would be affected by the greater or less diminution of parts already reduced in size and functionally useless. We have assumed that under the above stated unfavourable conditions a larger number of individuals are born with any particular part or organ diminished in size, than are born with it increased to the same relative degree; and as these individuals, having their already reduced and useless parts still more diminished by variation under poor conditions, would not be eliminated, they would intercross with the many individuals having the part of nearly average size, and with the few having it of increased size. The result of such intercrossing would be, in the course of time, the steady diminution and ultimate disappearance of all such useless parts. No doubt the process would take place with excessive slowness; but this result agrees perfectly with what we see in nature; for the number of forms possessing the merest traces of various organs is immense. I repeat that I have ventured to make these hypothetical remarks solely for the sake of calling attention to this subject. Charles Darwin Down, Beckenham, Kent, Sept. 20

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1874. Memorial presented to the First Lord of the Treasury [W. E. Gladstone]

Charles Wyville Thomson (1830–82), Scottish naturalist, oceanographer, specialist in marine invertebrates and professor of Natural History at Edinburgh. Thomson 1873. See [Richmond] CCD4, appendix 2. Living Cirripedia 1: 281–93. CD refers to Carl Eduard Adolph Gerstaecker (1828–95), German entomologist and zoologist, who doubted CD’s account of complemental males in Gerstaecker 1863, p. 410. A misprint for impregnation. Living Cirripedia 2: 307. St. George Jackson Mivart (1827–1900), barrister and biologist, Roman Catholic anti-Darwinian and lecturer in biology, St Mary’s Roman Catholic College, Kensington. Mivart 1871. Lambert Adolphe Jacques Quetelet (1796–1874), Belgian statistician. Quetelet 1835.

1873. [Note on nematodes]. In Cobbold, T. S., Notes on Entozoa—Part I. [Read 10 October] Proceedings of the Zoological Society of London 47 (18 November): 737. F1974 1. Filaria Horrida (Diesing). The first number and private reference on the list of a series of parasites which I received from Mr. Darwin in August 18691 refers to a set of worms obtained by him “from the stomach of an American Ostrich at Bahia Blanca, North Patagonia, in 1832.”

1

CD sent specimens in 1869 to Thomas Spencer Cobbold, (1828–86), physician, zoologist, and botanist who specialised in parasitic diseases. CD’s letter was later printed in Cobbold 1886 with further details about the specimens. See Cal: 6858 and 6876. In his notes from September 1832 CD recorded ‘400 E Intestinal worm taken out of the stomach of an Ostrich’ (rhea), Zoology notes, ‘Specimens in Spirits of Wine’, p. 333. The entire article by Cobbold, together with his drawing of CD’s specimens, is in Cobbold 1873.

1874. Memorial presented to the First Lord of the Treasury [W. E. Gladstone], respecting the National Herbaria. In Cavendish, S. C., Fourth report of the Royal Commission on the scientific instruction and the advancement of science. Parliamentary Papers, Command Papers; Reports of Commissioners, paper number (884), vol. XXII.1, pp. 31–2. F1954 [See p. 7.]1 To the Right Hon. W. E. Gladstone, First Lord of the Treasury Sir, The undersigned persons engaged in the pursuit of botany, or in instruction therein, desire to call your serious attention to a subject that deeply concerns the progress of Natural Science, and that of those branches of agriculture, horticulture, forestry, and manufactures that largely depend on Botanical Research. The First Commissioner of Works, in a Memorandum presented to Parliament before the close of last Session, clearly raised the question whether it is desirable to transfer to the branch

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of the British Museum about to be constructed at South Kensington, the Scientific Collections and Library now existing at Kew, and further stated that, pending the decision on that subject, he considers it his duty to take care that no new expense shall be incurred at Kew which will embarrass the Ministers of the Crown or the House of Commons in arriving at a decision. The Lords of the Treasury, in their Minute of the 24th July, decline to refer to that portion of the above-mentioned Memorandum, and no statement on that subject has since been made by any Minister of the Crown which shows whether it has received the attention of the Government. Being strongly of opinion that the proposed measure would be highly detrimental to the progress of Science, and injurious to all those interests that depend upon it, we beg to urge upon you that the subject is not one merely of Departmental Interest, and that it would not be unfitting your position, as First Minister of the Crown, to give your consideration to the following reasons, which we beg to urge in opposition to the proposed measure:— 1. That it appears to us that it is absolutely necessary that a great Botanical Garden like that at Kew, which is confessedly far the most important in the world, should be in close connexion with as perfect an Herbarium and Botanical Library as possible; and that these conditions are now fulfilled as far as circumstances and the present state of science will admit. 2. That such a combination of living and dead specimens is requisite for the complete study of plants, as regards their technical, physiological, and economic characters; and that the removal of the Herbarium would be a retrograde step in a scientific point of view. 3. That the records of the Colonial and India Offices will show of what immense importance the Establishment at Kew has been to the welfare of the entire British Empire, and that weighty questions are constantly submitted to the Director which require immediate attention, and which could not, in many cases, be satisfactorily answered without reference to the Library or Herbarium. 4. That every facility for the investigation of the intimate structure and general habit of plants, and the study of them in every point of view, which can reasonably be considered within the scope of pure Botany, is afforded by the Herbarium and Museum of Botany in connexion with the Garden, and that it would be easy to point out important labours in that direction which have been instituted at Kew, while the systematic treatment has always regarded the more minute characters as well as those which are superficial. 5. It has been remarked, indeed, that important works, such as the Hortus Kewensis, have been prepared without the aid of an Herbarium at Kew. We would, however, remark that the statement is not correct, as there was an Herbarium, which was dispersed before Sir W. J. Hooker became Director; and the conditions of Natural Science are at the present time so completely altered, that it is impossible to institute any fair comparison, the number of known species being enormously increased since the date of the publication in question. 6. That the Museums of Structural and Economic Botany, which owe their existence and importance to the late Sir W. J. Hooker, are often found of great value in the decision of critical points in the study of species, and that the severance of them from the Herbarium and Library would be a serious loss.

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7. That in the principal Botanic Gardens on the Continent, where effective work is done, there is in every case a large Herbarium connected with them. 8. That, in the interest of Botanical Science, we think it highly desirable that, besides the collections now existing at Kew, an Herbarium, or collection of dried plants, as complete as possible, should be maintained in connexion with the Natural History Museum which it is proposed to place at South Kensington, and that the two Herbariums should be in intimate relation with each other. 9. That from the delicate and perishable nature of its contents, and the necessity of referring to numerous specimens, an Herbarium cannot be made use of by many persons at the same time; and while it is desirable that students should have ready means of access at the National Museum in London to collections which may enable them to identify the plants of any particular country, it is still more essential that the authors of important works in Botanical Science should be enabled, as at present, to pursue their labours at Kew without interruption from casual visitors. 10. That an Herbarium is the least costly of all Collections in Natural History, and that which requires the least amount of space for its proper maintenance, in proportion to the number of objects which it contains. 11. That the arrangements of the Herbarium at Kew are so perfect, and the facilities for study so great, that it is resorted to from all parts of the world; and it would, therefore, be unwise to make a change which in the result is almost certain to be detrimental, and which, we are assured, would be especially distasteful to the leading Foreign Botanists. |32| Charles Darwin, M. A., F. R. S. [The other 53 names are omitted.]

1

One of the points on p. 7 of the Report introduces the memorial: 42. At present the Gardens occupy 300 acres, and are estimated to contain 20,000 species of plants; and the following Statement of the operations carried on at Kew is taken from a Memorial (signed by many eminent scientific men) presented to the First Lord of the Treasury in 1872. … Papers relating to Kew Gardens, p. 43, ordered by the House of Commons to be printed 25th of July 1872. See, also, a Second Memorial, Appendix II. Appendix II is entitled ‘Documents relating to the Botanical Collections at Kew and at the British Museum.’ including the present Memorial. A copy of this memorial was reprinted in Nature (16 January 1873): 212–13. See also Darwin 1872, F1937 (p. 373).

1874. Recent researches on termites and honey-bees. Nature 9 (19 February): 308–9. F1768 The accompanying letter, just received from Fritz Müller,1 in Southern Brazil, is so interesting that it appears to me well worth publishing in Nature. His discovery of the two sexually mature forms of Termites, |309| and of their habits, is now published in Germany;2 nevertheless few Englishmen will have as yet seen the account.

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In the German paper he justly compares, as far as function is concerned, the winged males and females of the one form, and the wingless males and females of the second form, with those plants which produce flowers of two forms, serving different ends, of which so excellent an account has lately appeared in Nature by his brother, Hermann Müller.3 The facts, also, given by Fritz Müller with respect to the stingless bees of Brazil will surprise and interest entomologists.4 Charles Darwin Feb. 11

1 2 3 4

Johann Friederich Theodor (Fritz) Müller (1822–97), German schoolmaster and naturalist in Brazil, elder brother of Hermann Müller, and a favourite correspondent of CD’s. F. Müller 1873. Heinrich Ludwig Hermann Müller (1829–83), German botanist. H. Müller 1873–4. Müller’s letter on the habits of certain termites and stingless honeybees is omitted. (DO)

1874. Fertilisation of the Fumariaceæ. Nature 9 (16 April): 460. F1769 I beg permission to make a few remarks on Mr. J. Traherne Moggridge’s statement (Nature, vol. ix. p. 423)1 that the flowers of Fumaria capreolata2 are at first pale or nearly white, and only attain their brightest colouring, becoming even crimson, after the ovaries are set. He then adds:—“If the reverse had been the case there is little doubt that we should have regarded the bright colouring as specially adapted to attract insects.” But does Mr. Moggridge know that these flowers are visited chiefly by diurnal insects? It has often been observed that flowers which are visited by moths are commonly white or very pale; but if they are odoriferous, they may be of any tint, even very dark or green. If therefore the flowers of the above Fumaria are visited by moths, it would be an injury to the plant had the flowers been from the first of a fine crimson. I have often seen bees sucking the flowers of the fumariaceous genera, Corydalis, Dielytra, and Adlumia; but many years ago I watched perseveringly the flowers of Fumaria officinalis and parvifora, and never saw them visited by a single insect; and I concluded from reasons which I will not here give (as I cannot find my original notes), that they were frequented during the night by small moths. Insects are not necessary for the fertilisation of Fumaria officinalis; for I covered up a plant, and it produced as many seeds as an uncovered one which grew near. On the other hand, with some species of Corydalis, the aid of insects is indispensable. With respect to the flowers of F. capreolata becoming brighter coloured as they grow old, we see the same thing in some hawthorns, and with the double rocket in our gardens. But is it surprising that this should sometimes occur with flowers, seeing that the leaves of a multitude of plants assume, as they become oxygenised, the most splendid tints during the autumn? Charles Darwin Down, Beckenham, Kent, April 6

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1874. Flowers of the primrose destroyed by birds

Moggridge 1873. White Ramping-Fumitory.

1874. Flowers of the primrose destroyed by birds. Nature 9 (23 April): 482. F1770 For above twenty years I have observed every spring in my shrubberies and in the neighbouring woods, that a large number of the flowers of the primrose are cut off, and lie strewn on the ground close round the plants. So it is sometimes with the flowers of the cowslip and polyanthus, when they are borne on short stalks. This year the devastation has been greater than ever; and in a little wood not far from my house many hundred flowers have been destroyed, and some clumps have been completely denuded. For reasons presently to be given, I have no doubt that this is done by birds; and as I once saw some green-finches flying away from some primroses, I suspect that this is the enemy. The object of the birds in thus cutting off the flowers long perplexed me. As we have little water hereabouts, I at one time thought that it was done in order to squeeze the juice out of the stalks; but I have since observed that they are as frequently cut during very rainy, as during dry weather. One of my sons then suggested that the object was to get the nectar of the flowers; and I have no doubt that this is the right explanation. On a hasty glance it appears as if the foot-stalk had been cut through; but on close inspection, it will invariably be found that the extreme base of the calyx and the young ovary are left attached to the foot-stalk. And if the cut-off ends of the flowers be examined, it will be seen that they do not fit the narrow cut-off ends of the calyx, which remains attached to the stalk. A piece of the calyx between one and two-tenths of an inch in length, has generally been cut clean away; and these little bits of the calyx can often be found on the ground; but sometimes they remain hanging by a few fibres to the upper part of the calyx of the detached flowers. Now no animal that I can think of, except a bird, could make two almost parallel clean cuts, transversely across the calyx of a flower. The part which is cut off contains within the narrow tube of the corolla the nectar; and the pressure of the bird’s beak would force this out at both the cut-off ends. I have never heard of any bird in Europe feeding on nectar; though there are many that do so in the tropical parts of the New and Old Worlds, and which are believed to aid in the crossfertilisation [= cross-pollination] of the species. In such cases both the bird and the plant would profit. But with the primrose it is an unmitigated evil, and might well lead to its extermination; for in the wood above alluded to many hundred flowers have been destroyed this season, and cannot produce a single seed. My object in this communication to Nature is to ask your correspondents in England and abroad to observe whether the primroses there suffer, and to state the result, whether negative or affirmative, adding whether primroses are abundant in each district.1 I cannot remember having formerly seen anything of the kind in the midland counties of England. If the habit of cutting off the flowers should prove, as seems probable, to be general, we must look at it as inherited or instinctive; for it is unlikely that each bird should have discovered during its individual life-time the exact spot

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where the nectar lies concealed within the tube of the corolla, and should have learnt to bite off the flowers so skilfully that a minute portion of the calyx is always left attached to the foot-stalk. If, on the other hand, the evil is confined to this part of Kent, it will be a curious case of a new habit or instinct arising in this primrose-decked land. Ch. Darwin Down, Beckenham, Kent, April 18

1

There were seven replies in Nature (30 April 1874): 509 and ten more in Nature (7 May 1874): 6–7. CD responded in Darwin 1874, F1771 (below).

1874. Flowers of the primrose destroyed by birds. Nature 10 (14 May): 24–25. F1771 I hope that you will permit me to make a few final remarks on the destruction of primrose flowers by birds. But first I must return my best thanks to your correspondents, as well as to some gentlemen who have written direct to me, and to whom I have not had time to send separate answers.1 Secondly, I must plead guilty to the high crime of inaccuracy. As the stalks from which the flowers had been cut were shrivelled, I mistook, in a manner now inexplicable to me, the base of the ruptured or removed ovarium for the summit; a remnant of the shrivelled placenta being mistaken for the base of the pistil. I have now looked more carefully, and find that on twelve stalks only three had any remnant of the ovarium left. I have also examined sixteen bits of the calyx which had been cut off by a caged bullfinch, presently to be noticed, and in fifteen of these not only had the ovarium been torn into fragments or quite destroyed, but all the ovules had been devoured, excepting sometimes one or two. In several cases the calyx had been split open longitudinally. The ovarium was in the same state in thirteen small portions of the calyx lying on the ground near a wild cowslip plant. It is therefore clear that the ovules are the chief attraction; but the birds in removing by pressure the ovules could not fail to squeeze out the nectar at the open end, as occurred when I squeezed similar bits between my fingers. The birds thus get a dainty morsel, namely, young ovules with sweet sauce. I still think that the nectar is, in part, the attraction, as caged bullfinches and canary birds much like sugar; but more especially because Mr. C. J. Monro2 has sent me some flowers from a cherry-tree near Barnet, which during several years has been attacked; and he finds many of the flowers, both those on the tree and on the ground, with rather large ragged holes in the calyx, like, but much larger than, those often made by humble bees when they rob flowers in an illegitimate manner. Now the inside of the flower of the cherry, round the ovarium, is bedewed (if protected from the visits of insects) with drops of nectar, which sometimes collect so as almost to fill up the bottom of the flower. In the case of the cherry I cannot doubt that this is the attraction, for I examined the ovarium of ten flowers, and although they had all been scored by the bird’s beak, and in four instances punctured, the ovule had in no case been devoured.

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To return to the primroses: from the accounts received, it seems that the flowers are cut off in the manner described by me, near Preston in Lancashire, in North Hampshire, Devonshire, and Ireland, as well as in Kent. In several other places, not worth specifying, where primroses are abundant, they have not been thus attacked; and this may possibly be due to the proper enemy, namely, as I now suspect, the bullfinch, not being a common bird. In my former letter I remarked that if the habit of cutting off the flowers proved to be a widely extended one, we should have to consider it as inherited or instinctive; as it is not likely that each bird should discover during its individual lifetime the exact spot where the nectar, and, as I must now add, the ovules, lie concealed, or should learn to bite off the flower so skilfully at the proper point. That the habit is instinctive, Prof. Frankland3 has given me interesting evidence. When he read my letter he happened to have in the room a bunch of cowslip flowers and a caged bullfinch, to whom he immediately gave some of the flowers, and afterwards many primrose flowers. The latter were cut off in exactly the same manner, and quite as neatly, as by the wild birds near here. I know that this is the case by having examined the cut-off portions. The bird worked so quickly that he easily destroyed twenty flowers in three minutes; a single wild pair would therefore cause great havoc. Prof. Frankland informs me that his bird pressed the cut-off portions of the calyx in its beak, and gradually worked them out on one side, and then dropped them. Thus the ovules were removed, and the nectar necessarily squeezed out. A canary bird to whom some cowslip and primrose flowers were given attacked all parts indiscriminately, and ate up the corolla, calyx, and stalks. A lady4 also informs me that her canary and siskin always attack primrose and cowslip flowers, if kept in the same room. They generally first make a ragged hole through the calyx opposite the ovarium, and remove the ovules, as I found to be the case with flowers which were sent to me; but the ovules had not been so well removed as by the bullfinch, and the nectar could not be obtained by this method of attack. But now comes the interesting point: the caged bullfinch just referred to was caught in 1872 near Ventnor, in the Isle of Wight, soon after it had left the nest, by which time the primroses would have been out of flower, and since then, as I hear from Prof. Frankland, it had never seen a primrose or cowslip flower. Nevertheless, as soon as this bird, now nearly two years old, saw these flowers, some machinery in its brain was set into action, which instantly told it in an unerring manner how and where to bite off and press the flowers, so as to gain the hidden prize. We are reminded by this little fact of Mr. Spalding’s5 admirable observations on the instinctive actions of chickens when their eyes were uncovered, after having been blind-folded from the moment of being hatched. Prof. Frankland seems to have been much struck with the behaviour of his bullfinch, and remarks in his letter that “it had all the precision of a chemical reaction; the result of putting a primrose within its reach can be almost as certainly predicted as that of putting a plate of iron into a solution of sulphate of copper.” Charles Darwin Down, Beckenham, Kent, May 7

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P.S.—This letter was printed before I saw your last number, and I am glad to find that some of my statements are confirmed, more especially with respect to bullfinches. During the last fortnight not one primrose has been attacked in the little wood where shortly before there was such havoc. I imagined that the pair of bullfinches, which I saw there earlier in the season, had wandered away; but yesterday evening (May 10) it occurred to me that the flowers produced late in the season might fail to secrete nectar, or that the recent cold weather might have produced this effect. Accordingly, in the afternoon I gathered fifteen flowers from as many distinct plants, and kept them in water in my room for seventeen hours. Earlier in the season I treated some flowers in this same manner, and found the tube of the corolla full of nectar; but now only one of the flowers contained a very small quantity of nectar, another showing a |25| mere trace of it. And the flowers being no longer cut off by the birds supports my belief that the nectar is one chief attraction to them; the ovules without the sauce not being worth the gathering. I may add that as the primrose is a dimorphic plant, these non-nectariferous flowers would be sterile, for they would not be visited by insects.—C.D.

1 2 3 4 5

See Darwin 1873, F1770 (above) note 1. Cecil James Monro (1833–82), mathematician, wrote to CD 26 April 1874. Cal: 9428. Edward Frankland (1825–99), chemist, Cal: 9430. Thereza Mary Story-Maskelyne, née Dillwyn Llewelyn (1834–1926), writing 4 May 1874. Cal: 9426. Spalding 1872.

1874. [Memoranda on Drosera filiformis]. In Canby, W. M., Observations on Drosera filiformis. American Naturalist 8, no. 7 (July): 396–7. F19321 Some observations on the power of the insect-trapping “thread leaved sundew” to bend its leaves partly or wholly about its prey, may serve to supplement the interesting notes of Mrs. Mary Treat recorded in the December number of the American Naturalist.2 They were made about the middle of last August during a day’s botanical excursion in the vicinity of “Pleasant Mills,” New Jersey, and were suggested by Mr. Darwin in the following memoranda: (1.) “Put a small atom of crushed fly on a leaf of Drosera filiformis near the apex and observe whether the solid leaf itself, after twenty-four hours or so, curls over the fly.” (2.) “Rub roughly with the point of a fine needle half a dozen times a few glands, and observe whether they become inflected after a few minutes, or more probably after a few hours.”3

1

William Marriott Canby (1831–1904), American botanist and businessman. CD cited Canby’s findings throughout Insectivorous plants.

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1875. Memorial to A. H. Gordon, Governor of Mauritius

Mary Treat (1830–1923), American botanist who provided information for Insectivorous plants. Treat 1873. These memoranda were enclosed in a 22 October 1872 letter from CD to Asa Gray (Cal: 8568). Gray told CD in a letter of 2 December 1872 (Cal: no. 8656) that the memoranda were being sent to Canby.

1874. [Irritability of Pinguicula]. Gardeners’ Chronicle and Agricultural Gazette no. 2 (4 July): 15. F1767 The leaves of Pinguicula vulgaris,1 according to Mr. Darwin, possess a power of digesting animal matter similar to that shown by the Sundews (Drosera). Albumen, fibrin, meat or cartilage induce a secretion from the glands of the upper surface of the leaf, and their secretion becomes feebly acid (but not so much so as that of Drosera). Their secretion is reabsorbed, and causes an aggregation of the protoplasm in the cells of the glands, such as had been observed in other similar cases. Before excitement the glands were seen to be filled with a homogeneous pale greenish fluid; after the aggregation of the protoplasm it can be seen to move. When a row of insects or of Cabbage seeds are placed near the margin of a leaf (or when a single insect is placed at one point,) the whole margin (or one point) becomes curled considerably over in two or three hours; the apex of the leaf will not turn over towards the base. Small fragments of glass also cause a similar movement, but to a much less degree. The inflexed margin pours forth a secretion which envelopes the flies or seeds, but pieces of glass cause no, or hardly any, increase of secretion. But here comes a puzzle: If the flies or fly be removed, the margin of the leaf turns back in less than twenty-four hours; but it does so also when a row of flies and Cabbage seeds are left adhering; so that the use or meaning of the inflexion is at present quite a puzzle.

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Pinguicula = butterworts. CD’s report was read to the Royal Horticultural Society on 1 July and was reprinted in Nature (30 July) p. 258. CD’s results were published in Insectivorous plants, (1875) chapter 16.

1875. [Memorial to A. H. Gordon, Governor of Mauritius, requesting the protection of the Giant Tortoise on Aldabra]. Transactions of the Royal Society of Arts and Sciences of Mauritius n.s. 8: 106–9. F2006 To His Excellency The Honorable SIR ARTHUR HAMILTON GORDON, K. C. M. G.,1 Governor and Commander in Chief of Mauritius and its Dependencies. 1. We the undersigned respectfully beg to call the attention of the Colonial Government of Mauritius to the imminent extermination of the Gigantic Land Tortoises of the Mascarenes, commonly called “Indian Tortoises.”

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2. These animals were formerly abundant in the Mauritius, Reunion, Rodrigues and other islands of the Western part of the Indian Ocean. Being highly esteemed as food, easy of capture and transport, they formed for many years, a staple supply to ships touching at those islands for refreshment. |107| 3. No means being taken for their protection they have become extinct in nearly all these islands, and Aldabra is now the only locality where the last remains of this animal form are known to exist in a state of nature. 4. We have been informed that the Government of Mauritius have granted a concession of Aldabra to parties who intend to cut the timber on this island. If this project be carried out, or if otherwise the island be occupied, it is to be feared, nay certain, that all the Tortoises remaining in this limited area will be destroyed by the workmen employed. 5. We would, therefore, earnestly submit it to the consideration of Your Excellency whether it would not be practicable that the Government of Mauritius should cause as many of these animals as possible to he collected before the wood cutting parties or others land with the view of their being transferred to the Mauritius or the Seychelle Islands, where they might be deposited in some enclosed ground or park belonging to the Government, and protected as property of the Colony. 6. In support of the statements above made and the plan now submitted to the Mauritius Government the following passages may be quoted from Grant’s “History of Mauritius.” (1801, 4):2 P. 194. “We (in Mauritius) possess a great abundance of both Land and Sea Turtle which are not only a great resource for the supply of our ordinary wants, but serve to barter with the crews of ships.” P. 100. “The best production of Rodriguez is the |108| land-turtle which is in great abundance. Small vessels a[r]e constantly employed in transporting them by thousands to the Isle of Mauritius for the service of the hospital.” P. 101. “The principal point of view (in Rodrigues) is, first, the French Governor’s house, or rather that of the Superintendent, appointed by the Governor of the Isle of France, to direct the cultivation of the gardens there, and to overlook the park of land-turtles. Secondly, the park of land-turtles which is on the sea-shore facing the house.” 7. The rescue and protection of these animals is, however, recommended to the Colonial Government less on account of their utility (which now-a-days might be questioned in consideration of their diminished number, reduced size and slow growth, and of the greatly improved system of provisioning ships which renders the crews independent of such casual assistance) than on account of the great scientific interest attached to them. With the exception of a similar tortoise in the Galapagos islands (now also fast disappearing) that of the Mascarenes is the only surviving link reminding us of those still more gigantic forms which once inhabited the Continent of India in a past geological age. It is one of the few remnants of a curious group of animals once existing on a large submerged continent of which the Mascarenes formed the highest points. It flourished with the Dodo and Solitaire, and whilst it is a matter

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1875. [Letter to Haeckel on the origins of Darwin’s theory of evolution]

of lasting regret that not even a few individuals of these curious birds should have had a chance of surviving the lawless and disturbed condition of past centuries, it is confidently hoped that the present Government and people who support the “Royal Society of Arts and |109| Sciences of Mauritius” will find the means of saving the last examples of a contemporary of the Dodo and Solitaire. London, April 1874. (Signed by) Charles Darwin, [F]. R. S. [The other five names are omitted.]

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Arthur Charles Hamilton-Gordon (1829–1912), Governor of Mauritius 1871–74. This item was written by Albert Charles Lewis Gotthilf Günther (1830–1914), German-born zoologist, Assistant keeper of the zoological department of the British Museum, 1872–75. This was written in response to the first proposal to establish a wood-cutting colony on Aldabra. The memorial was not successful. See Stoddart 1971. The memorial was reprinted with minor alterations in Günther 1877, pp. 20–22. Numerous printing errors suggest the typesetters were unaccustomed to English. Grant 1801.

1875. [Letter to Haeckel on the origins of Darwin’s theory of evolution]. In Schmidt, O., The doctrine of descent and Darwinism. London: H. S. King & Co. 2d ed., pp. 132–3. F1916 Having reflected much on the foregoing facts, it seemed to me probable that allied species were descended from a common ancestor. But during several years I could not conceive how each form could have been modified so as to become admirably adapted to its place in nature. I began, therefore, to study domesticated animals and cultivated plants, and after a time perceived that man’s power of selecting and breeding from certain individuals was the most powerful of all means in the production of new races. Having attended to the habits of animals and their relations to the surrounding conditions, I was able to realize the severe struggle for existence to which all organisms are subjected; and my geological observations had allowed me to appreciate to a certain extent the duration of past geological periods. With my mind thus prepared I fortunately happened to read Malthus’s “Essay on Population;” and the idea of natural selection through the struggle for existence at once occurred to me. Of all the subordinate points in the theory, the last which I understood was the cause of the tendency in the |133| descendants from a common progenitor to diverge in character.1

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CD provided Schmidt with a translation of his letter published in German in Haeckel 1868. Ernst Heinrich Philipp August Haeckel (1834–1919), German biologist, physician and zealous supporter of CD. The letter later appeared again in English in Haeckel 1876, 1: 134.

1876. [Letters to J. Torbitt on potato propagation]

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1876. [Letters to J. Torbitt on potato propagation]. In Torbitt, J., Cras credemus. A treatise on the cultivation of the potato from the seed, having for proposed results the extinction of the disease, and a yield of thirty, forty or more tons of tubers per statute acre. Belfast: Alexander Mayne. F19781 Authorized Copy Down, Beckenham, Kent, April 4th, 1876. I cannot but think that the principle on which you are acting is right, and if you succeed you will have conferred an enormous benefit on the public. I am sorry that I was compelled to decline my answer being published, for I cannot to the present hour remember what I said. Dear Sir, yours faithfully, Ch. Darwin. J. Torbitt, Esq., Belfast.2 The “principle on which I am acting” is growth of the potato from the seed and propagation of those varieties only, which do not become diseased. The answer referred to was a reply, which Mr. Darwin was good enough to make to my question: What is an individual? The following telegrams require no explanation:— Belfast, 6th April, 1876. From James Torbitt to Ch. Darwin, Esq. Letter received with profound thanks. I can make it suppress the potato-disease five years sooner, if published. May I? Down, 6th April, 1876. From Ch. Darwin to J. Torbitt You may publish what I have said.

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This single sheet was presumably inserted in some copies of Torbitt’s 1876 pamphlet Cras credemus (‘tomorrow we believe’), which, as the title page declared, was ‘Sent, accompanied by a Packet of Seed, to each Member of the House of Lords; each Member of the House of Commons; and the Principal Landlords of Ulster.’ The addendum is not in the BL or National Herbarium of Ireland, Dublin copies. It was printed some time before 22 April. See the correspondence between Torbitt and Darwin in Cal. The items of correspondence reproduced on this sheet correspond to Cal: 10440, 20267, 20268 and 20269 respectively. The editors of the Correspondence provided invaluable assistance with this material. James Torbitt, a wealthy wine merchant and grocer in Belfast, believed he could produce potatoes that would be impervious to potato blight by breeding selectively from those seedlings which best resisted the disease and repeating the process over multiple generations. See also Darwin 1878, F1979 (p. 421) and Darwin 1879, F1982.

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1876. Royal Commission on the practice of subjecting live animals to experiments

1876. [Evidence given to the Commission]. Report of the Royal Commission on the practice of subjecting live animals to experiments for scientific purposes; with the minutes of evidence and appendix. London: Her Majesty’s Stationery Office, pp. 233–4. F1275 Wednesday, 3rd November 1875.1 Present: The Right Hon. Viscount Cardwell, in the Chair. The Right Hon. Lord Winmarleigh. Sir J. B. Karslake, M. P. Thomas Henry Huxley, Esq.

John Eric Erichsen, Esq. Richard Holt Hutton, Esq. N. Baker, Esq., Secretary.

Mr. Charles Darwin called in and examined 4661. (Chairman.) We are very sensible of your kindness in coming at some sacrifice to yourself to express your opinions to the Commission. We attribute it to the great interest which we know you take in the subject referred to us, both on the score of science and also on the score of humanity?—Yes, I have felt a great interest in it. 4662. I think you took part in preparing the resolutions, |234| of the British Association at their meeting in Edinburgh in 1871?—No; I had nothing to do with that. I was very glad to see them, and approved of them; but I had nothing to do with the framing of those resolutions; I did not attend the meeting. 4663. But you signed a petition which embodied them?—When they were sent to me I may have done so. I do not remember it; but if my signature is attached I must have given it; I had forgotten it. 4664: But you cordially approved of them?—I cordially approved of them. I had occasion to read them over lately at the time when this subject was beginning to be agitated. I read them over with care and highly approved of them then. 4665. I think you took some part in the preparation of a Bill which was ultimately laid before the House of Commons by Dr. Lyon Playfair?—In the steps preparatory to that Bill, but the Bill itself did not exactly express the conclusions at which after consultation with several physiologists we arrived; I apprehend that it was accidentally altered. 4666. But in the main you were an approving party?—In the main. 4667. You have never, I think, yourself, either directly or indirectly been connected with the practice of trying experiments upon living animals?—Never. 4668. Will you have the kindness to state to us the views which you desire to lay before the Commission in connexion with it?—The first thing that I would say is, that I am fully convinced that physiology can progress only by the aid of experiments on living animals. I cannot think of any one step which has been made in physiology without that aid. No

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doubt many surmises with regard to the circulation of the blood could be formed from the position of the valves in the veins, and so forth, but certainty such as is required for the progress of any science can be arrived at in the case of physiology only by means of experiments on living animals. 4669. Then I need hardly ask you what your opinion is as to the notion of prohibiting them altogether?—In my opinion it would be a very great evil, because many reasons, mostly general, but some special, may be assigned for a full conviction that hereafter physiology cannot fail to confer the highest benefits on mankind. Many grounds, I think, can be assigned for this conviction. 4670. Is it your opinion that most of the experiments can be performed while the animal is entirely insensible to pain?—That is my belief; but I ought to state that I have no claim to rank as a physiologist. I have, during many years, read largely on the subject, both general treatises and special papers, and in that respect I have gained some general knowledge, but as I have said, I have no claim to be called a physiologist, and I have had nothing to do in teaching physiology; but from all I can learn, the exceptions are extremely few in which an animal could not be experimented on in a state of entire insensibility. 4671. Then to hesitate to perform experiments, though painful in their nature, when the animal was rendered insensible, would not be, in your opinion, a judicious course to recommend to the Queen and Parliament?—Certainly not. It is unintelligible to me how anybody could object to such experiments. I can understand a Hindoo, who would object to an animal being slaughtered for food, disapproving of such experiments, but it is absolutely unintelligible to me on what ground the objection is made in this country. 4672. Now with regard to trying a painful experiment without anæsthetics, when the same experiment could be made with anæsthetics, or, in short, inflicting any pain that was not absolutely necessary upon any animal, what would be your view on that subject?—It deserves detestation and abhorrence. The witness withdrew.

1

See LL3: 199–210, ML2: 435–41 and Darwin 1881, F1352 (p. 441).

1876. Cherry blossoms. Nature 14 (11 May): 28. F1772 In the last number of Nature (vol. xiv , p 10), Mr Pryor1 states that the flowers of the wild cherry are bitten off in large numbers in much the same manner as I formerly described in the case of the primrose. Some days ago I observed many cherry blossoms in this state, and to day I saw some actually falling I approached stealthily so as to discover what bird was at work, and behold it was a squirrel. There could be no doubt about it for the squirrel was low

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in the tree and actually had a blossom between its teeth. It is none the less true that birds likewise bite the flowers of the cherry tree. Charles Darwin Down, Beckenham, May 6

1 Alfred Reginald Pryor (1839–81), botanist. Pryor 1876.

1876. Sexual selection in relation to monkeys. Nature 15 (2 November): 18–19. F1773 In the discussion on Sexual Selection in my “Descent of Man,” no case interested and perplexed me so much as the brightly-coloured hinder ends and adjoining parts of certain monkeys.1 As these parts are more brightly coloured in one sex than the other, and as they become more brilliant during the season of love, I concluded that the colours had been gained as a sexual attraction. I was well aware that I thus laid myself open to ridicule; though in fact it is not more surprising that a monkey should display his bright-red hinder end than that a peacock should display his magnificent tail. I had, however, at that time no evidence of monkeys exhibiting this part of their bodies during their courtship; and such display in the case of birds affords the best evidence that the ornaments of the males are of service to them by attracting or exciting the females. I have lately |19| read an article by Joh. von Fischer, of Gotha, published in Der Zoologische Garten, April, 1876,2 on the expression of monkeys under various emotions, which is well worthy of study by any one interested in the subject, and which shows that the author is a careful and acute observer. In this article there is an account of the behaviour of a young male mandrill when he first beheld himself in a looking-glass, and it is added, that after a time he turned round and presented his red hinder end to the glass. Accordingly I wrote to Herr J. von Fischer to ask what he supposed was the meaning of this strange action, and he has sent me two long letters full of new and curious details, which will, I hope, be hereafter published.3 He says that he was himself at first perplexed by the above action, and was thus led carefully to observe several individuals of various other species of monkeys, which he has long kept in his house. He finds that not only the mandrill (Cynocephalus mormon) but the drill (C. leucophœus) and three other kinds of baboons (C. hamadryas, sphinx, and babouin), also Cynopithecus niger, and Macacus rhesus and nemestrinus, turn this part of their bodies, which in all these species is more or less brightly coloured, to him when they are pleased, and to other persons as a sort of greeting. He took pains to cure a Macacus rhesus, which he had kept for five years, of this indecorous habit, and at last succeeded. These monkeys are particularly apt to act in this manner, grinning at the same time, when first introduced to a new monkey, but often also to their old monkey friends; and after this mutual display they begin to play together. The young mandrill ceased spontaneously after a time to act in this manner towards his master, von Fischer, but continued to do so towards persons who were strangers and to new

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monkeys. A young Cynopithecus niger never acted, excepting on one occasion, in this way towards his master, but frequently towards strangers, and continues to do so up to the present time. From these facts von Fischer concludes that the monkeys which behaved in this manner before a looking-glass (viz., the mandrill, drill, Cynopithecus Niger, Macacus rhesus, and nemestrinus) acted as if their reflection were a new acquaintance. The mandrill and drill, which have their hinder ends especially ornamented, display it even whilst quite young, more frequently and more ostentatiously than do the other kinds. Next in order comes Cynocephalus hamadryas, whilst the other species act in this manner seldomer. The individuals, however, of the same species, vary in this respect, and some which were very shy never displayed their hinder ends. It deserves especial attention that von Fischer has never seen any species purposely exhibit the hinder part of its body, if not at all coloured. This remark applies to many individuals of Macacus cynamolgus and Cercocebus radiatus (which is closely allied to M. rhesus), to three species of Cercopithecus and several American monkeys. The habit of turning the hinder ends as a greeting to an old friend or new acquaintance, which seems to us so odd, is not really more so than the habits of many savages, for instance that of rubbing their bellies with their hands, or rubbing noses together. The habit with the mandrill and drill seems to be instinctive or inherited, as it was followed by very young animals; but it is modified or guided, like so many other instincts, by observation, for von Fischer says that they take pains to make their display fully, and if made before two observers, they turn to him who seems to pay the most attention. With respect to the origin of the habit, von Fischer remarks that his monkeys like to have their naked hinder ends patted or stroked, and that they then grunt with pleasure. They often also turn this part of their bodies to other monkeys to have bits of dirt picked off, and so no doubt it would be with respect to thorns. But the habit with adult animals is connected to a certain extent with sexual feelings, for von Fischer watched through a glass door a female Cynopithecus niger, and she during several days, “umdrehte und dem Männchen mit gurgelnden Tönen die stark geröthete Sitzfläche zeigte, was ich früher nie an diesem Thier bemerkt hatte. Beim Anblick dieses Gegenstandes erregte sich das Männchen sichtlich, denn es polterte heftig an den Stäben, ebenfalls gurgelnde Laute ausstossend,” [turned around and, with gurgling tones, showed the male a strongly reddened posterior, which I had never previously observed in this animal. At the sight of this object the male became visibly excited as he beat heavily on the bars, and likewise emitting loud gurgling sounds] As all the monkeys which have the hinder parts of their bodies more or less bright coloured live, according to von Fischer, in open rocky places, he thinks that these colours serve to render one sex conspicuous at a distance to the other; but as monkeys are such gregarious animals, I should have thought that there was no need for the sexes to recognise each other at a distance. It seems to me more probable that the bright colours, whether on the face or hinder end, or, as in the mandrill, on both, serve as a sexual ornament and attraction. Anyhow, as we now know that monkeys have the habit of turning their hinder ends towards other monkeys, it ceases to be at all surprising that it should have been this part of their bodies which has been more or less decorated. The fact that it is only the monkeys thus characterised which, as far as at present known, act in this manner as a greeting towards other monkeys, renders it

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doubtful whether the habit was first acquired from some independent cause, and that afterwards the parts in question were coloured as a sexual ornament; or whether the colouring and the habit of turning round were first acquired through variation and sexual selection, and that afterwards the habit was retained as a sign of pleasure or as a greeting, through the principle of inherited association. This principle apparently comes into play on many occasions: thus it is generally admitted that the songs of birds serve mainly as an attraction during the season of love, and that the leks, or great congregations of the black grouse, are connected with their courtship; but the habit of singing has been retained by some birds when they feel happy, for instance by the common robin, and the habit of congregating has been retained by the black grouse, during other seasons of the year. I beg leave to refer to one other point in relation to sexual selection. It has been objected that this form of selection, as far as the ornaments of the males are concerned, implies that all the females within the same district must possess and exercise exactly the same taste. It should, however, be observed in the first place, that although the range of variation of a species may be very large, it is by no means indefinite. I have elsewhere given a good instance of this fact in the pigeon,4 of which there are at least a hundred varieties differing widely in their colours, and at least a score of varieties of the fowl differing in the same manner;5 but the range of colour in these two species is extremely distinct. Therefore the females of natural species cannot have an unlimited scope for their taste. In the second place, I presume that no supporter of the principle of sexual selection believes that the females select particular points of beauty in the males; they are merely excited or attracted in a greater degree by one male than by another, and this seems often to depend, especially with birds, on brilliant colouring. Even man, excepting perhaps an artist, does not analyse the slight differences in the features of the woman whom he may admire, on which her beauty depends. The male mandrill has not only the hinder end of his body, but his face gorgeously coloured and marked with oblique ridges, a yellow beard, and other ornaments. We may infer from what we see of the variation of animals under domestication, that the above several ornaments of the mandrill were gradually acquired by one individual varying a little in one way, and another individual in another way. The males which were the handsomest or the most attractive in any manner to the females would pair oftenest, and would leave rather more offspring than other males. The offspring of the former, although variously intercrossed, would either inherit the peculiarities of their fathers, or transmit an increased tendency to vary in the same manner. Consequently the whole body of males inhabiting the same country, would tend from the effects of constant intercrossing to become modified almost uniformly, but sometimes a little more in one character and sometimes in another, though at an extremely slow rate; all ultimately being thus rendered more attractive to the females. The process is like that which I have called unconscious selection by man, and of which I have given several instances. In one country the inhabitants value a fleet or light dog or horse, and in another country a heavier and more powerful one; in neither country is there any selection of the individual animals with lighter or stronger bodies and limbs; nevertheless after a considerable lapse of time the individuals are found to have been modified in the desired manner almost uniformly, though differently in each country. In two absolutely

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distinct countries inhabited by the same species, the individuals of which can never during long ages have intermigrated and intercrossed, and where, moreover, the variations will probably not have been identically the same, sexual selection might cause the males to differ. Nor does the belief appear to me altogether fanciful that two sets of females, surrounded by a very different environment, would be apt to acquire somewhat different tastes with respect to form, sound, or colour. However this may be, I have given in my “Descent of Man” instances of closely-allied birds inhabiting distinct countries, of which the young and the females cannot be distinguished, whilst the adult males differ considerably, and this may be attributed with much probability to the action of sexual selection.6 Charles Darwin.

1 2 3 4 5 6

Descent 2: 290–4. This article was reprinted in Descent 2d ed. 12th thousand (1877) and subsequent printings. Johann von Fischer (1850–1901), German zoologist. Fischer 1876. Fischer 1877. See Cal: 10598 and 10600. Variation 1: chapters 5–6. ‘manner’ was altered to ‘kind of way’ when reprinted in Descent. Descent 2: chapters 13–16.

1877. [Letter on Stock Dove]. In Kingsley, F. E. ed., Charles Kingsley: his letters and memories of his life. London: Henry S. King & Co., 2: 135–6. F1951 With respect to the pigeons, your remarks clearly show me (without seeing specimens) that the birds shot were the stock C. Œnas,1 long confounded with the cushat and rock pigeon. It is in some respects identical in appearance and habits; as it breeds in holes in trees and in |136| rabbit warrens. It is so far intermediate that it quite justifies what you say on all the forms being descendants of one…..

1

Columba Œnas or Stock Dove. Charles Kingsley (1819–75), Anglican clergyman, author and naturalist. He was the ‘celebrated author and divine’ quoted in Origin 2d ed., p. 481 See CCD10: 71.

1877. Holly berries. Gardeners’ Chronicle and Agricultural Gazette 7, no. 159 (6 January): 19. F1774 Several of your correspondents have noticed the scarcity of Holly-berries in different parts of the country, and the same thing may be observed to a remarkable extent in this neighbourhood. Your correspondents account for the fact by spring frosts, but it must be remembered how hardy a plant the Holly is, being found in Norway as far north as the 62d degree of north latitude (Lecoq Géographie Botanique, vii., p. 370),1 another explanation seems to me more probable. Bees of all kinds were in this neighbourhood extraordinarily rare during the spring. I can state this positively, as I wished to observe a particular point

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1877. [The scarcity of holly berries and bees]

in their behaviour in sucking the common red Clover; and, therefore, often visited the fields where this plant was growing; but I could see very few bees. I was so much struck by this fact that I examined several meadows abounding with flowers of all kinds, but bees were everywhere rare. Reflecting, in the course of the summer, on this extraordinary scarcity, it occurred to me that this part of England would be temporarily in the same predicament as New Zealand before the introduction of hive bees, when the Clovers (which, as I know by trial, require the aid of bees for perfect fertilisation) would not set seed. By an odd chance I received the very next morning a letter from a stranger in Kent, asking me if I could assign any reason for the seed-crop of Clover having largely failed in his neighbourhood, though the plants looked vigorous and healthy. Now the Holly is a dioecious plant, and during the last forty years I have looked at many flowers in different districts, and have never found an hermaphrodite. Bees are the chief transporters of pollen from the male to the female tree, and the latter will produce but few berries if bees are scarce. In my Origin of Species I state that, having found a female tree exactly 60 yards from a male tree, I put the stigmas of twenty flowers, taken from different branches, under the microscope, and on all, without exception, there were a few pollen-grains, and on some a profusion.2 As the wind had set for several days from the female to the male tree, the pollen could not thus have been carried. The weather had been cold and boisterous, and therefore not favourable; nevertheless every female flower which I examined had been effectually fertilised by the bees, which I saw at work, and which had flown from tree to tree in search of nectar. Therefore, as I believe, we cannot decorate our Christmas hearths with the scarlet berries of the Holly, because bees were rare during the spring; but what caused their rarity I do not in the least know. Charles Darwin, Down, Beckenham, Kent, Jan. 3.

1 2

Lecoq 1854–8. Origin p. 93. See CD’s subsequent letter to the Gardeners’ Chronicle Darwin 1877, F1775 (below).

1877. [The scarcity of holly berries and bees]. Gardeners’ Chronicle and Agricultural Gazette 7, no. 160 (20 January): 83. F1775 I beg a little space in your journal to confess my error with respect to the cause of the scarcity of Holly berries.1 I have been convinced of this by the two communications in your last number, by a statement in the Garden by Mr. Fish,2 and by some private letters which I have received. It appears that several causes in combination have led to this scarcity; but I still think that the rarity of bees of all kinds in this neighbourhood during the spring, of which fact I feel assured, may have played a part, though a quite subordinate one. Charles Darwin, Down, Beckenham, Jan. 17.

1 2

CD refers to Darwin 1877, F1774 (above). David Taylor Fish (1824–1901), professional gardener and horticultural journalist. Fish 1877.

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1877. To members of the Down Friendly Club. [np: np] F13031 As one of your Honorary Members who has acted to the best of his power as your Treasurer for the last Twenty-seven years, I hope that you will permit me to address a few words to you, on this important occasion, when you have to decide whether the Club shall be dissolved. You founded and joined this Club in order to receive assistance when ill or when permanently invalided, and to be decently buried when dead; and is it not an extraordinary fact that you should now wish to dissolve the Club, for no other reason that I can hear of, except that it is now rich and in a perfectly sound condition? I have been informed that absurd rumours are afloat that the Government intends to unite all the Clubs throughout England into a single one, and then divide their Funds. I can assure you that all such rumours are lies, spread for some evil purpose. I am also informed that an actuary has calculated that you may divide £150, but that about £1,000 must be retained in order to ensure the safety of the Club. I suppose some of you think that this is a larger sum than is necessary, but let me beg you to remember that an actuary can have no motive to deceive you, and that he has great means for obtaining accurate information as to what are the chances of sickness and death, about which no ordinary man can form any judgment. No reasonable man will doubt that the above sum is necessary to pay the Burial Fees and to ensure Provision during ill-health, to which every Member of the Club is liable. Remember how many unregistered Clubs, not only in this neighbourhood but throughout England, have become bankrupt, and have left their Members destitute in their old age. Therefore I hope that you will allow me to warn you all in the most earnest manner, to deliberate for a long time before you dissolve the Club, not only for the sake of your wives and children, but for your own sakes, so as to avoid the degradation of being supported by the Union. The younger Members should reflect that they will receive only a small sum, and for this they forego all the advantages of belonging to a really safe Club; and the elder Members will find it impossible to join any Club which can pretend to safety. Should you resolve to dissolve our Club, all your officers, including myself, are bound under the penalty of imprisonment to see that every provision of the law is strictly followed, and this will cause much delay and expense; but as far as lies in my power the law shall be obeyed. Finally, I hope that you will admit that I can have no bad motive in expressing my deliberate judgment: it is no pleasure to me to keep your accounts and to subscribe to your funds, except in the hope of doing some small good to my fellow Members, who have hitherto always treated me in a considerate and friendly manner. I remain Your faithful Treasurer, Charles Darwin. Down, February 19, 1877.

1

CD was invited to act at treasurer for the village Friendly Club in 1850 and continued to keep its accounts for thirty years. The Club was a form of insurance for illness, loss of work, retirement and death. Francis Darwin recalled in LL1: 142–3: He took much trouble about the club, keeping its accounts with minute and scrupulous exactness, and taking pleasure in its prosperous condition. Every Whit-Monday the club used to march round

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with band and banner, and paraded on the lawn in front of the house. There he met them, and explained to them their financial position in a little speech seasoned with a few well-worn jokes. Freeman 1977 observed: After the Friendly Societies Act of 1875 (38 & 39 Vict. Ch. 60), and an amending Act of 1876 (39 & 40 Vict. Ch. 22), under which the Downe Club would have been placed in Class 5 ‘Local Village and Country Societies’, there seems to have been dissatisfaction; some members wanted to disband and share out the proceeds. The leaflet was distributed to members, in February 1877, to dissuade them, successfully, from this course. Emma Darwin (Vol. II, p. 237) wrote to Francis on Whit Tuesday, February 3rd, 1879, that the band was expected that day. CD’s accounts show: 18 March 1852 Smith & Elder. Printing 250 Rules for Down Club £3.5. Registered at Friendly Societies, 17 North Audley Street, W1. File number for Downe Club F51/232, but the file passed to Public Record Office.

1877. Fertilisation of plants. Gardeners’ Chronicle and Agricultural Gazette 7, no. 162 (24 February): 246. F1780 In the last number of the Gardeners’ Chronicle (p. 203) Mr. Henslow1 quotes my words, that “the seeds from wh[i]ch the self-fertilised plants of the third generation (of Petunia) were raised were not well ripened.”2 The word self-fertilised is a misprint for crossed, as he would have seen if he had looked to the full account of my experiments given at p. 191, where I say, “The sole conjecture which I can form is that the crossed seeds had not been sufficiently ripened, &c.” But I have no right to expect a critic to take so much trouble, and I am much obliged to him for having led me to detect this unfortunate misprint. Mr. Henslow then goes on to say that “Mr. Darwin also accounts for the greater growth of the eighth generation of Ipomœa from their having been raised from unhealthy seeds.” He ought I think, to have added that the greater growth of the self-fertilised plants was confined to the early part of their lives, and that they were ultimately beaten in height by the crossed plants in the ratio of one hundred to eighty-five. It was this anomalous manner of growth which led me to compare these plants with those of Iberis which were raised from seeds not well ripened. I have long been convinced that controversy is a mere waste of time; I will, therefore, not make any other remarks on Mr. Henslow’s criticisms, though I think that I could answer them satisfactorily. I hope that any reader who is interested in the subject will not take Mr. Henslow’s interpretation of my statements without consulting my book. Charles Darwin, February 19.

1 2

Henslow 1877. Cross and self fertilisation, p. 275.

1877. [Letter of thanks]. In Harting, P., Testimonial to Mr. Darwin—Evolution in the Netherlands. Nature 15 (8 March): 410–12. F1776 Down, Beckenham, February 12 Sir,1— I received yesterday the magnificent present of the album, together with your letter. I hope that you will endeavour to find some means to express to the 217 distinguished

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observers and lovers of natural science, who have sent me their photographs, my gratitude for their extreme kindness. I feel deeply gratified by this gift, and I do not think that any testimonial more honourable to me could have been imagined. I am well aware that my books could never have been written, and would not have made any impression on the public mind, had not an immense amount of material been collected by a long series of admirable observers, and it is to them that honour is chiefly due. I suppose that every worker at science occasionally feels depressed, and doubts whether what he has published has been worth the labour which it has cost him; but for the remaining years of my life, whenever I want cheering, I will look at the portraits of my distinguished co-workers in the field of science, and remember their generous sympathy. When I die the album will be a most precious bequest to my children. I must further express my obligation for the very interesting history contained in your letter of the progress of opinion in the Netherlands, with respect to evolution, the whole of which is quite new to me. I must again thank all my kind friends from my heart for their ever-memorable testimonial, and I remain, Sir, Your obliged and grateful servant, (Signed) Charles R. Darwin

1

Addressed to Adrian Anthoni van Bemmelen (1830–97), Dutch zoologist, ornithologist and president of the Netherlands Zoological Society. CD’s birthday was 12 February. CD’s letter, with an explanation, including remarks about Lyell’s 1858 visit to the Netherlands and his discussion of CD’s long-term and forthcoming species work, was forwarded by Pieter Harting (1812–85), Dutch zoologist and microscopist.

1877. Scrofula and in-breeding. Agricultural Gazette (2 April): 324–5. F1972 Dear Sir,1—You ask my opinion as to whether the employment of a bull supposed to be scrofulous is consistent with the ultimate interest of the breeder. As a general rule I should defer to the judgment of any one who had experience on such a point, supposing that he was not biassed by interest or prejudice. But in this particular instance we have such good evidence of the inheritance of constitutional diseases, such as scrofula, consumption, &c., that it seems to me very rash to breed from an animal thus tainted. In all probability a large majority of the offspring from a scrofulous bull, paired with a perfectly sound cow, would be to all appearance sound, but it can hardly be doubted that the evil would be latent in many of them, and ready to break out in subsequent generations. I will venture to add a few remarks on the general question of close interbreeding. Sexual reproduction is so essentially the same in plants and animals, that I think we may fairly apply conclusions drawn from the one kingdom to the other. From a long series of experiments on plants, given in my book On the Effects of Cross and Self-Fertilisation, the conclusion seems clear that there is no mysterious evil in the mere fact of the nearest relations breeding together; but that evil follows (independently of inherited disease or weakness) from the

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circumstance of near relations generally possessing a closely similar constitution. However little we may be able to explain the cause, the facts detailed by me show that the male and female sexual elements must be differentiated to a certain degree, in order to unite properly, and to give birth to a vigorous progeny. Such differentiation of the sexual elements follows from the parents and their ancestors having lived during some generations under different conditions of life. The closest interbreeding does not seem to induce variability or a departure from the typical form of the race or family, but it causes loss of size, of constitutional vigour in resisting unfavourable influences, and often of fertility. On the other hand, a cross between plants of the same sub-variety, which have been grown during some generations under different conditions, increases to an extraordinary degree the size and vigour of the offspring. Some kinds of plants bear self-fertilisation [= self-pollination] much better than others; nevertheless it has been proved that these profit greatly by a cross with a fresh stock. So it appears to be with animals, for Short-horn cattle—perhaps all cattle—can withstand close interbreeding with very little injury; but if they could be crossed with a distinct stock without any loss of their excellent qualities, it would be a most surprising fact if the offspring did not also profit in a very high degree in constitutional vigour. If, therefore, any one chose to risk breeding from an animal which suffered from some inheritable disease or weakness, he would act wisely to look out, not merely for a perfectly sound animal of the other sex, but for one belonging to another strain which had |325| been bred, during several generations at a distant place, under as different conditions of soil, climate, &c., as possible, for in this case he might hope that the offspring, by having gained in constitutional vigour would be enabled to throw off the taint in their blood.—Charles Darwin, March 22.

1

John Chalmers Morton (1821–88), farmer, prolific author of agricultural works and editor of the Agricultural Gazette. Morton wrote to CD on 19 March 1877, see Cal: 10905.

1877. [Memorial] Zoology of the ‘Challenger’ Expedition. Nature 16 (14 June): 118. F2003 As in a letter upon this subject in the number of the Annals of Natural History for May last Dr. P. Martin Duncan,1 writing as president of the Geological Society, has stated that he speaks ‘at the instance of a very considerable number of members of learned societies,’ we, the undersigned, wish to state that we do not agree in the strictures passed by Dr. Duncan upon the manner in which Sir C. Wyville Thomson has distributed the specimens collected by the Challenger Expedition for description. So far as we have had an opportunity of judging we are perfectly satisfied that Sir C. Wyville Thomson, in the arrangements which he has made as regards these collections, has acted consistently with the best interest of science. It was, in our opinion, Sir C. Wyville Thomson’s duty to secure the aid of the most competent naturalists without regard to their nationality; and, even if it were proper that

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national jealousies should be imported into science, Sir C. Wyville Thomson can hardly be reproached on this score, when it is considered that two-thirds at least of the naturalists whose aid he has obtained are Englishmen. Charles Darwin. [The other 12 names are omitted.]

1

Peter Martin Duncan (1824–91), physician, invertebrate palaeontologist and president of the Geological Society of London, 1876–8. Duncan 1877.

1877. Note to Mr. Francis Darwin’s paper. Quarterly Journal of Microscopical Science 17 (July): 272. F1777 I beg leave to say that I have witnessed almost all the facts described in the foregoing paper,1 and can vouch for their accuracy. To the best of my judgment, the whole case is a most remarkable one, and well deserves the attention of physiologists. Charles Darwin.

1

F. Darwin 1877b. See Darwin 1877, F1778 (p. 417).

1877. A biographical sketch of an infant. Mind 2, no. 7 (July): 285–94. F1779 M. Taine’s very interesting account of the mental development of an infant, translated in the last number of Mind (p. 252),1 has led me to look over a diary which I kept thirty-seven years ago with respect to one of my own infants.2 I had excellent opportunities for close observation, and wrote down at once whatever was observed. My chief object was expression, and my notes were used in my book on this subject; but as I attended to some other points, my observations may possibly possess some little interest in comparison with those by M. Taine, and with others which hereafter no doubt will be made. I feel sure, from what I have seen with my own infants, that the period of development of the several faculties will be found to differ considerably in different infants. During the first seven days various reflex actions, namely sneezing, hickuping, yawning, stretching, and of course sucking and screaming, were well performed by my infant. On the seventh day, I touched the naked sole of his foot with a bit of paper, and he jerked it away, curling at the same time his toes, like a much older child when tickled. The perfection of these reflex movements shows that the extreme imperfection of the voluntary ones is not due to the state of the muscles or of the coordinating centres, but to that of the seat of the will. At this time, though so early, it seemed clear to me that a warm soft hand |286| applied to his face excited a wish to suck. This must be considered as a reflex or an instinctive action, for it is impossible to believe that experience and association with the touch of his mother’s breast

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could so soon have come into play. During the first fortnight he often started on hearing any sudden sound, and blinked his eyes. The same fact was observed with some of my other infants within the first fortnight. Once, when he was 66 days old, I happened to sneeze, and he started violently, frowned, looked frightened, and cried rather badly: for an hour afterwards he was in a state which would be called nervous in an older person, for every slight noise made him start. A few days before this same date, he first started at an object suddenly seen; but for a long time afterwards sounds made him start and wink his eyes much more frequently than did sight; thus when 114 days old, I shook a paste-board box with comfits in it near his face and he started, whilst the same box when empty or any other object shaken as near or much nearer to his face produced no effect. We may infer from these several facts that the winking of the eyes, which manifestly serves to protect them, had not been acquired through experience. Although so sensitive to sound in a general way, he was not able even when 124 days old easily to recognise whence a sound proceeded, so as to direct his eyes to the source. With respect to vision,—his eyes were fixed on a candle as early as the 9th day, and up to the 45th day nothing else seemed thus to fix them; but on the 49th day his attention was attracted by a bright-coloured tassel, as was shown by his eyes becoming fixed and the movements of his arms ceasing. It was surprising how slowly he acquired the power of following with his eyes an object if swinging at all rapidly; for he could not do this well when seven and a half months old. At the age of 32 days he perceived his mother’s bosom when three or four inches from it, as was shown by the protrusion of his lips and his eyes becoming fixed; but I much doubt whether this had any connection with vision; he certainly had not touched the bosom. Whether he was guided through smell or the sensation of warmth or through association with the position in which he was held, I do not at all know. The movements of his limbs and body were for a long time vague and purposeless, and usually performed in a jerking manner; but there was one exception to this rule, namely, that from a very early period, certainly long before he was 40 days old, he could move his hands to his own mouth. When 77 days old, he took the sucking bottle (with which he was partly fed) in his right hand, whether he was held on the left or right arm of his nurse,3 and he would not take it in his left hand |287| until a week later although I tried to make him do so; so that the right hand was a week in advance of the left. Yet this infant afterwards proved to be left-handed, the tendency being no doubt inherited—his grandfather, mother, and a brother having been or being left-handed. When between 80 and 90 days old, he drew all sorts of objects into his mouth, and in two or three weeks’ time could do this with some skill; but he often first touched his nose with the object and then dragged it down into his mouth. After grasping my finger and drawing it to his mouth, his own hand prevented him from sucking it; but on the 114th day, after acting in this manner, he slipped his own hand down so that he could get the end of my finger into his mouth. This action was repeated several times, and evidently was not a chance but a rational one. The intentional movements of the hands and arms were thus much in advance of those of the body and legs; though the purposeless movements of the latter were from a very early period usually alternate as in the act of walking. When four months old, he often looked intently at his own hands and other objects

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close to him, and in doing so the eyes were turned much inwards, so that he often squinted frightfully. In a fortnight after this time (i.e. 132 days old) I observed that if an object was brought as near to his face as his own hands were, he tried to seize it, but often failed; and he did not try to do so in regard to more distant objects. I think there can be little doubt that the convergence of his eyes gave him the clue and excited him to move his arms. Although this infant thus began to use his hands at an early period, he showed no special aptitude in this respect, for when he was 2 years and 4 months old, he held pencils, pens, and other objects far less neatly and efficiently than did his sister4 who was then only 14 months old, and who showed great inherent aptitude in handling anything. Anger.—It was difficult to decide at how early an age anger was felt; on his eighth day he frowned and wrinkled the skin round his eyes before a crying fit, but this may have been due to pain or distress, and not to anger. When about ten weeks old, he was given some rather cold milk and he kept a slight frown on his forehead all the time that he was sucking, so that he looked like a grown-up person made cross from being compelled to do something which he did not like. When nearly four months old, and perhaps much earlier, there could be no doubt, from the manner in which the blood gushed into his whole face and scalp, that he easily got into a violent passion. A small cause sufficed; thus, when a little over seven months old, he screamed with rage because a lemon slipped away and he could not seize it with his hands. When eleven months old, if |288| a wrong plaything was given to him, he would push it away and beat it; I presume that the beating was an instinctive sign of anger, like the snapping of the jaws by a young crocodile just out of the egg, and not that he imagined he could hurt the plaything. When two years and three months old, he became a great adept at throwing books or sticks, &c., at anyone who offended him; and so it was with some of my other sons. On the other hand, I could never see a trace of such aptitude in my infant daughters; and this makes me think that a tendency to throw objects is inherited by boys. Fear.—This feeling probably is one of the earliest which is experienced by infants, as shown by their starting at any sudden sound when only a few weeks old, followed by crying. Before the present one was 4½ months old I had been accustomed to make close to him many strange and loud noises, which were all taken as excellent jokes, but at this period I one day made a loud snoring noise which I had never done before; he instantly looked grave and then burst out crying. Two or three days afterwards, I made through forgetfulness the same noise with the same result. About the same time (viz. on the 137th day) I approached with my back towards him and then stood motionless; he looked very grave and much surprised, and would soon have cried, had I not turned round; then his face instantly relaxed into a smile. It is well known how intensely older children suffer from vague and undefined fears, as from the dark, or in passing an obscure corner in a large hall, &c. I may give as an instance that I took the child in question, when 2¼ years old, to the Zoological Gardens, and he enjoyed looking at all the animals which were like those that he knew, such as deer, antelopes &c., and all the birds, even the ostriches, but was much alarmed at the various larger animals in cages. He often said afterwards that he wished to go again, but not to see “beasts in houses”; and we could in no manner account

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for this fear. May we not suspect that the vague but very real fears of children, which are quite independent of experience, are the inherited effects of real dangers and abject superstitions during ancient savage times? It is quite conformable with what we know of the transmission of formerly well-developed characters, that they should appear at an early period of life, and afterwards disappear. Pleasurable Sensations.—It may be presumed that infants feel pleasure whilst sucking, and the expression of their swimming eyes seems to show that this is the case. This infant smiled when 45 days, a second infant when 46 days old; and these were true smiles, indicative of pleasure, for their eyes brightened and eyelids slightly closed. The smiles arose chiefly when looking at their mother, and were therefore probably of mental origin; |289| but this infant often smiled then, and for some time afterwards, from some inward pleasurable feeling, for nothing was happening which could have in any way excited or amused him. When 110 days old he was exceedingly amused by a pinafore being thrown over his face and then suddenly withdrawn; and so he was when I suddenly uncovered my own face and approached his. He then uttered a little noise which was an incipient laugh. Here surprise was the chief cause of the amusement, as is the case to a large extent with the wit of grown-up persons. I believe that for three or four weeks before the time when he was amused by a face being suddenly uncovered, he received a little pinch on his nose and cheeks as a good joke. I was at first surprised at humour being appreciated by an infant only a little above three months old, but we should remember how very early puppies and kittens begin to play. When four months old, he showed in an unmistakable manner that he liked to hear the pianoforte played; so that here apparently was the earliest sign of an æsthetic feeling, unless the attraction of bright colours, which was exhibited much earlier, may be so considered. Affection.—This probably arose very early in life, if we may judge by his smiling at those who had charge of him when under two months old; though I had no distinct evidence of his distinguishing and recognising anyone, until he was nearly four months old. When nearly five months old, he plainly showed his wish to go to his nurse. But he did not spontaneously exhibit affection by overt acts until a little above a year old, namely, by kissing several times his nurse who had been absent for a short time. With respect to the allied feeling of sympathy, this was clearly shown at 6 months and 11 days by his melancholy face, with the corners of his mouth well depressed, when his nurse pretended to cry. Jealousy was plainly exhibited when I fondled a large doll, and when I weighed his infant sister, he being then 15½ months old. Seeing how strong a feeling jealousy is in dogs, it would probably be exhibited by infants at an earlier age than that just specified, if they were tried in a fitting manner. Association of Ideas, Reason, &c.—The first action which exhibited, as far as I observed, a kind of practical reasoning, has already been noticed, namely, the slipping his hand down my finger so as to get the end of it into his mouth; and this happened on the 114th day. When four and a half months old, he repeatedly smiled at my image and his own in a mirror, and no doubt mistook them for real objects; but he showed sense in being evidently surprised at my voice coming from behind him. Like all infants he much enjoyed thus looking at himself,

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and in less than two months perfectly understood that it was |290| an image; for if I made quite silently any odd grimace, he would suddenly turn round to look at me. He was, however, puzzled at the age of seven months, when being out of doors he saw me on the inside of a large plate-glass window, and seemed in doubt whether or not it was an image. Another of my infants, a little girl, when exactly a year old, was not nearly so acute, and seemed quite perplexed at the image of a person in a mirror approaching her from behind. The higher apes which I tried with a small looking-glass behaved differently; they placed their hands behind the glass, and in doing so showed their sense, but far from taking pleasure in looking at themselves they got angry and would look no more. When five months old, associated ideas arising independently of any instruction became fixed in his mind; thus as soon as his hat and cloak were put on, he was very cross if he was not immediately taken out of doors. When exactly seven months old, he made the great step of associating his nurse with her name, so that if I called it out he would look round for her. Another infant used to amuse himself by shaking his head laterally: we praised and imitated him, saying “Shake your head”; and when he was seven months old, he would sometimes do so on being told without any other guide. During the next four months the former infant associated many things and actions with words; thus when asked for a kiss he would protrude his lips and keep still,—would shake his head and say in a scolding voice “Ah” to the coal-box or a little spilt water, &c., which he had been taught to consider as dirty. I may add that when a few days under nine months old he associated his own name with his image in the looking-glass, and when called by name would turn towards the glass even when at some distance from it. When a few days over nine months, he learnt spontaneously that a hand or other object causing a shadow to fall on the wall in front of him was to be looked for behind. Whilst under a year old, it was sufficient to repeat two or three times at intervals any short sentence to fix firmly in his mind some associated idea. In the infant described by M. Taine (pp. 254–256) the age at which ideas readily became associated seems to have been considerably later, unless indeed the earlier cases were overlooked. The facility with which associated ideas due to instruction and others spontaneously arising were acquired, seemed to me by far the most strongly marked of all the distinctions between the mind of an infant and that of the cleverest full-grown dog that I have ever known. What a contrast does the mind of an infant present to that of the pike, described by Professor Möbius,* who during three whole months dashed and |291| stunned himself against a glass partition which separated him from some minnows; and when, after at last learning that he could not attack them with impunity, he was placed in the aquarium with these same minnows, then in a persistent and senseless manner he would not attack them! Curiosity, as M. Taine remarks, is displayed at an early age by infants, and is highly important in the development of their minds; but I made no special observation on this head. Imitation likewise comes into play. When our infant was only four months old I thought that *

Die Bewegungen der Thiere, &c., 1873, p. 11. [Karl August Möbius (1825–1908), German zoologist. Möbius 1873. CD cited the same case in Descent 2d ed. (1882) p. 75.]

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he tried to imitate sounds; but I may have deceived myself, for I was not thoroughly convinced that he did so until he was ten months old. At the age of 11½ months he could readily imitate all sorts of actions, such as shaking his head and saying “Ah” to any dirty object, or by carefully and slowly putting his forefinger in the middle of the palm of his other hand, to the childish rhyme of “Pat it and pat it and mark it with T”. It was amusing to behold his pleased expression after successfully performing any such accomplishment. I do not know whether it is worth mentioning, as showing something about the strength of memory in a young child, that this one when 3 years and 23 days old on being shown an engraving of his grandfather, whom he had not seen for exactly six months, instantly recognised him and mentioned a whole string of events which had occurred whilst visiting him, and which certainly had never been mentioned in the interval. Moral Sense.—The first sign of moral sense was noticed at the age of nearly 13 months: I said “Doddy (his nickname) won’t give poor papa a kiss,–naughty Doddy”. These words, without doubt, made him feel slightly uncomfortable; and at last when I had returned to my chair, he protruded his lips as a sign that he was ready to kiss me; and he then shook his hand in an angry manner until I came and received his kiss. Nearly the same little scene recurred in a few days, and the reconciliation seemed to give him so much satisfaction, that several times afterwards he pretended to be angry and slapped me, and then insisted on giving me a kiss. So that here we have a touch of the dramatic art, which is so strongly pronounced in most young children. About this time it became easy to work on his feelings and make him do whatever was wanted. When 2 years and 3 months old, he gave his last bit of gingerbread to his little sister, and then cried out with high self-approbation “Oh kind Doddy, kind Doddy”. Two months later, he became extremely sensitive to ridicule, and was so suspicious that he often thought people who were laughing and talking together were laughing at him. A little later (2 years and 7½ months old) I met him |292| coming out of the dining room with his eyes unnaturally bright, and an odd unnatural or affected manner, so that I went into the room to see who was there, and found that he had been taking pounded sugar, which he had been told not to do. As he had never been in any way punished, his odd manner certainly was not due to fear, and I suppose it was pleasurable excitement struggling with conscience. A fortnight afterwards, I met him coming out of the same room, and he was eyeing his pinafore which he had carefully rolled up; and again his manner was so odd that I determined to see what was within his pinafore, notwithstanding that he said there was nothing and repeatedly commanded me to “go away,” and I found it stained with pickle-juice; so that here was carefully planned deceit. As this child was educated solely by working on his good feelings, he soon became as truthful, open, and tender, as anyone could desire. Unconsciousness, Shyness.—No one can have attended to very young children without being struck at the unabashed manner in which they fixedly stare without blinking their eyes at a new face; an old person can look in this manner only at an animal or inanimate object. This, I believe, is the result of young children not thinking in the least about themselves, and therefore not being in the least shy, though they are sometimes afraid of strangers. I saw the first symptom of shyness in my child when nearly two years and three months old: this was shown towards myself, after an absence of ten days from home, chiefly by his eyes being

1877. A biographical sketch of an infant

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kept slightly averted from mine; but he soon came and sat on my knee and kissed me, and all trace of shyness disappeared. Means of Communication.—The noise of crying or rather of squalling, as no tears are shed for a long time, is of course uttered in an instinctive manner, but serves to show that there is suffering. After a time the sound differs according to the cause, such as hunger or pain. This was noticed when this infant was eleven weeks old, and I believe at an earlier age in another infant. Moreover, he appeared soon to learn to begin crying voluntarily, or to wrinkle his face in the manner proper to the occasion, so as to show that he wanted something. When 46 days old, he first made little noises without any meaning to please himself, and these soon became varied. An incipient laugh was observed on the 113th day, but much earlier in another infant. At this date I thought, as already remarked, that he began to try to imitate sounds, as he certainly did at a considerably later period. When five and a half months old, he uttered an articulate sound “da” but without any meaning attached to it. When a little over a year old, he used gestures |293| to explain his wishes; to give a simple instance, he picked up a bit of paper and giving it to me pointed to the fire, as he had often seen and liked to see paper burnt. At exactly the age of a year, he made the great step of inventing a word for food, namely mum, but what led him to it I did not discover. And now instead of beginning to cry when he was hungry, he used this word in a demonstrative manner or as a verb, implying “Give me food”. This word therefore corresponds with ham as used by M. Taine’s infant at the later age of 14 months. But he also used mum as a substantive of wide signification; thus he called sugar shu-mum, and a little later after he had learned the word “black,” he called liquorice black-shu-mum,— black-sugar-food. I was particularly struck with the fact that when asking for food by the word mum he gave to it (I will copy the words written down at the time) “a most strongly marked interrogatory sound at the end”. He also gave to “Ah,” which he chiefly used at first when recognising any person or his own image in a mirror, an exclamatory sound, such as we employ when surprised. I remark in my notes that the use of these intonations seemed to have arisen instinctively, and I regret that more observations were not made on this subject. I record, however, in my notes that at a rather later period, when between 18 and 21 months old, he modulated his voice in refusing peremptorily to do anything by a defiant whine, so as to express “That I won’t”; and again his humph of assent expressed “Yes, to be sure”. M. Taine also insists strongly on the highly expressive tones of the sounds made by his infant before she had learnt to speak. The interrogatory sound which my child gave to the word mum when asking for food is especially curious; for if anyone will use a single word or a short sentence in this manner, he will find that the musical pitch of his voice rises considerably at the close. I did not then see that this fact bears on the view which I have elsewhere maintained that before man used articulate language, he uttered notes in a true musical scale as does the anthropoid ape Hylobates.5 Finally, the wants of an infant are at first made intelligible by instinctive cries, which after a time are modified in part unconsciously, and in part, as I believe, voluntarily as a means of communication,—by the unconscious expression of the features,—by gestures and in a marked manner by different intonations,—lastly by words of a general nature invented by himself, then of a more precise nature imitated from those which he hears; and these latter are acquired at a wonderfully quick rate. An infant understands to a certain extent, and as

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|294| I believe at a very early period, the meaning or feelings of those who tend him, by the expression of their features. There can hardly be a doubt about this with respect to smiling; and it seemed to me that the infant whose biography I have here given understood a compassionate expression at a little over five months old. When 6 months and 11 days old he certainly showed sympathy with his nurse on her pretending to cry. When pleased after performing some new accomplishment, being then almost a year old, he evidently studied the expression of those around him. It was probably due to differences of expression and not merely of the form of the features that certain faces clearly pleased him much more than others, even at so early an age as a little over six months. Before he was a year old, he understood intonations and gestures, as well as several words and short sentences. He understood one word, namely, his nurse’s name, exactly five months before he invented his first word mum; and this is what might have been expected, as we know that the lower animals easily learn to understand spoken words. Charles Darwin.

1 2

3 4 5

Hippolyte Taine (1828–93), French critic and historian. Taine 1877 was a translation of Taine 1876. CD refers to his 1839–41 notes on his first-born son William Erasmus Darwin (1839–1914) (DAR210). (DO) In his Autobiography (pp. 131–2) CD wrote: My first child was born on December 27th, 1839, and I at once commenced to make notes on the first dawn of the various expressions which he exhibited, for I felt convinced, even at this early period, that the most complex and fine shades of expression must all have had a gradual and natural origin. In the same year this article was translated into French, German and Russian and, in 1914, Armenian. Lengthy extracts appeared again in Mind in Champneys 1881. CD recorded observations of his other children which were published in CCD4, appendix 3 and DO. Possibly Mary Bennett. See CCD2: 335 note 3. Anne Elizabeth Darwin (1841–51). Descent 2: 277.

1877. [Memorial to Earl Carnarvon on the proposed South African Confederation by the Committee of the Aborigines Protection Society]. The Times (23 July): 10. F1926 The following memorial with reference to the proposed South African Confederation has been forwarded to the Earl of Carnarvon by the Committee of the Aborigines Protection Society:– To the Right Hon. the Earl of Carnarvon,1 Her Majesty’s Principal Secretary of State for the Colonies. We beg respectfully to address your Lordship on the subject of the proposed establishment in South Africa of a confederation of Colonies and States. We observe, with great regret, that your Lordship, in a despatch addressed to his Excellency Sir Henry Barkly2 on December 14, expresses an opinion against any direct representation of natives in the Legislative Assembly of the Union. We have no desire to see masses of uncivilized men invested with political rights which they would be wholly unable to exercise in either a responsible or an intelligent manner; but

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we venture to submit, on the ground alike of justice and of policy, that native Africans who have acquired both education and property should not be excluded from the possession of the elective franchise. We understand that in this particular no distinction of race is recognized in the Australian Colonies; while in the Cape colony itself, as well as in New Zealand and in the Dominion of Canada, equal civil and political privileges have long been placed—with the best results— within reach of such individual members of the aboriginal race as are able to comply with the requirements of the law. We think it is of the utmost importance that when a new Constitution is in course of being framed for a country in the position of South Africa, the organic law of the State should embody the principle of an equality of rights, without regard to colour or race, leaving the principle itself to be applied only to those natives who have qualified themselves for the satisfactory performance of the duties of citizenship. We, therefore, earnestly hope that your Lordship will take steps to insure to the civilised portion of the coloured population of the British Dependencies in South Africa civil and political privileges, similar to those which it may be intended to confer upon persons of European descent. We feel that such a policy would entirely accord with the spirit which has hitherto characterized your Lordship’s administration of native affairs. We have the honour to be your Lordship’s obedient servants, Charles Darwin [The lengthy list of co-signatories is omitted.] 17, King William-street, Strand, July 20, 1877.

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Henry Howard Molyneux Earl of Carnarvon (1831–90), Conservative secretary of state for the colonies. Henry Barkly (1815–98), governor of the Cape colony and British high commissioner in South Africa.

1877. The contractile filaments of the teasel. Nature 10 (23 August): 339. F1778 The observations of my son Francis on the contractile filaments protruded from the glands of Dipsacus,* offer so new and remarkable a fact in the physiology of plants, that any confirmation of them is valuable. I hope therefore that you will publish the appended letter from Prof. Cohn,1 of Breslau, whom every one will allow to be one of the highest authorities in Europe on such a subject. Prof. Cohn’s remarks were not intended for publication, but he has kindly allowed me to lay them before your readers. [Cohn’s letter is omitted.] In a subsequent letter, Prof. Cohn describes what appear to him as thinned points or pores in the cell wall of the glands from which the filaments seem to be protruded. He also *

Abstract published in Proc. Roy. Soc., 1877, no. 179; published in full in Quarterly Journal of Microscopical Science, July, 1877. [F. Darwin 1877a and F. Darwin 1877b. See Darwin 1877, F1777 (p. 409).]

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mentions the very curious fact which he has discovered, that by adding iodine to the detached epidermis of the leaf cups of Dipsacus the whole fluid contents of the epidermis cells turn blue like diluted starch paste, although no starch grains are met with in any epidermis cell except in the stomata.* He adds that the basal cell of the gland becomes blue, while the rest of it and the excreted globules are stained yellow. I may add that I have heard from Prof. Hoffmann, of Giessen, that he formerly observed contractile filament of a somewhat similar nature on the annulus of Agaricus muscarius. He has described them in the Botanische Zeitung,1853, and figured them, ibid.,1859, tab. xi. Fig. 17.2 Charles Darwin Down, Beckenham, August 15

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Ferdinand Julius Cohn (1828–98), German botanist, bacteriologist and professor of plant physiology, Breslau. Hermann Hoffmann (1819–91), German botanist. Hoffmann 1853 was translated into English: On contractile tissues in the Hymenomycetes. Transactions of the Microscopical Society of London (1854): 243–250; Hoffmann 1859.

1877. Fritz Müller on flowers and insects. Nature 17 (29 November): 78. F1781 The enclosed letter from that excellent observer, Fritz Müller, contains some miscellaneous observations on certain plants and insects of South Brazil, which are so new and curious that they will probably interest your naturalist readers.1 With respect to his case of bees getting their abdomens dusted with pollen while gnawing the glands on the calyx of one of the Malpighiaceæ,2 and thus effecting the cross-fertilisation [= cross-pollination] of the flowers, I will remark that this case is closely analogous to that of Coronilla recorded by Mr. Farrer in your journal some years ago, in which parts of the flowers have been greatly modified, so that bees may act as fertilisers while sucking the secretion on the outside of the calyx.3 The case is interesting in another way. My son Francis4 has shown that the food bodies of the Bull’s-horn Acacia, which are consumed by the ants that protect the tree from its enemies (as described by Mr. Belt),5 consist of modified glands; and he suggests that aboriginally the ants licked a secretion from the glands, but that at a subsequent period the glands were rendered more nutritious and attractive by the retention of the secretion and other changes, and that they were then devoured by the ants. But my son could advance no case of glands being thus gnawed or devoured by insects, and here we have an example. With respect to Solanum palinacanthum, which bears two kinds of flowers on the same plant, one with a long style and large stigma, the other with a short style and small stigma, I think more evidence is requisite before this species can be considered as truly heterostyled,6 for I find that the pollen-grains from the two forms do not differ in diameter. Theoretically it would be a great anomaly if flowers on the same plant were *

Prof. Cohn adds that the blue coloration of the epidermis by iodine occurs in the leaves of Ornithogalum.

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functionally heterostyled, for this structure is evidently adapted to insure the cross-fertilisation of distinct plants. Is it not more probable that the case is merely one of the same plant bearing male flowers through partial abortion, together with the original hermaphrodite flowers? Fritz Müller justly expresses surprise at Mr. Leggett’s7 suspicion that the difference in length of the pistil in the flowers of Pontederia cordata8 of the United States is due to difference of age; but since the publication of my book9 Mr. Leggett has fully admitted, in the Bulletin of the Torrey Botanical Club, that this species is truly heterostyled and trimorphic.10 The last point on which I wish to remark is the difference between the males and females of certain butterflies in the neuration of the wings, and in the presence of tufts of peculiarly-formed scales. An American naturalist has recently advanced this case as one that cannot possibly be accounted for by sexual selection. Consequently, Fritz Müller ’s observations, which have been published in full in a recent number of Kosmos, are to me highly interesting, and in themselves highly remarkable.11 Charles Darwin Down, Beckenham, Kent, November 21

1 2 3 4 5 6 7 8 9 10 11

Müller ’s letter, which discusses the pollination of flowers by insects and certain butterflies with scent-producing scales thought to attract females, is omitted. (DO) A family of tropical shrubs. Thomas Henry Farrer (1819–99), civil servant and botanist. Farrer 1874. F. Darwin 1877. Thomas Belt (1832–78), geologist and mining engineer. Belt 1874, p. 218. Heterostylous plants have two or three types of flowers, though always the same type per individual plant. William Henry Leggett (1816–82), American botanist. Leggett 1875. See Cal: 10790. Pontederia cordata = Pickerel weed, an aquatic plant. Forms of flowers, p. 187. Leggett 1877. Müller 1877.

1877. Growth under difficulties. Gardeners’ Chronicle and Agricultural Gazette 8 (29 December): 805. F1782 The enclosed branch of Cotyledon (Echeveria stolonifera) was cut from a plant growing in my greenhouse, and was suspended on August 10 in my study, which is a dry room, and in which a fire burns most of the year. It has sent out two fine flowering stems which, from the position in which the branch was hung, have bent upwards (as may be seen in the figure). They have now (December 6) begun to flower. You will see that the plant has sent out a number of small roots. I may add that the specimen weighed on September 1 45.46 grammes, on December 6 36.94 grammes, so that its growth has continued in spite of a considerable loss from evaporation. Charles Darwin, Down, Beckenham.1

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1878. Mr. Darwin at Down

CD’s letter is set within an article by the editors of the Gardeners’ Chronicle which is omitted. (DO) The parenthetical words ‘as may be seen in the figure’ were added by the editors.

[Report of conversation]. 1878. Mr. Darwin at Down. In [Yates, Edmund Hodgson]. Celebrities at Home. Reprinted from ‘The World’. Second series. London: Office of ‘The World’, pp. 223–30. F1999 ‘It is better so,’ says Mr. Darwin, ‘than to be interviewed and harassed with questions which cannot be answered without some appearance of vanity. Moreover it strikes me as not proper

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that a man should communicate anything to the author of a biographical notice. He should behave as if already dead.’ 1878. [Extracts of letters on potato cultivation]. In Torbitt, J., Cultivation of the Potato. To the Right Hon. Sir Stafford H. Northcote Bart., C. B., Chancellor of the Exchequer, &c., London. [Belfast: privately printed single sheet]. F19791 As to the question of the probability of a continuance of their comparative immunity from disease for some years forward, Mr. Darwin, writing on the 14th April, 1876, does me the high honour to say that “the more I reflect on your scheme the more I believe it is the one plan for succeeding in getting a sound variety;” and again on 30th July, 1877, he permits me to say “that my plan—namely, the preservation during successive generations of those seedling plants, all the tubers of which are sound, and the destruction of all other plants, in conjunction with cross-fertilization—is in his opinion by far the most likely method by which to obtain a sound variety;” and that “I have his best wishes that I may have the satisfaction of conferring a great benefit on the world.”

1

See Darwin to Torbitt 30 July 1877 where this wording was suggested by CD, Cal: 11081. Torbitt had this letter printed in the hope of acquiring funding to support his work. Only the passage containing the quotations from Darwin is included here. (DO) See also Darwin 1876, F1978 (p. 397).

1878. Prefatory letter. In Kerner, A., Flowers and their unbidden guests. With a prefatory letter by Charles Darwin, M. A., F. R. S. The translation revised and edited by W. Ogle, M.A., M.D. London: C. Kegan Paul. F1318 My Dear Dr. Ogle,1—I am extremely glad to hear that you have undertaken to edit Kerner’s work on Flowers and their Unbidden Guests;2 for it opens out a highly original and curious field of research. It is possible that some of Kerner’s generalisations may hereafter require to be slightly modified; but I feel sure that every remark which he has made well deserves careful consideration. The beauty and poetry of flowers will not be at all lessened to the general observer, by his being led through Kerner’s investigation to notice various small, and apparently quite unimportant, details of structure,—such as the presence of differently directed hairs, viscid glands, etc., which prevent the access of certain insects, and not of others. He will, I believe, come to the conclusion that flowers are not only delightful from their beauty and fragrance, |vi| but display most wonderful adaptations for various purposes. I cordially wish that your translation may find many readers, not so much for your sake as for theirs. Believe me very faithfully yours, Charles Darwin.Down, Beckenham, Kent, August 17, 1878.

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1878. Transplantation of shells

William Ogle (1827–1912), physician, naturalist and superintendent of Statistics to the Registrar-General. Anton Kerner von Marilaun (1831–98), German botanist. Kerner 1876. CD’s annotated copy is in DAR139.15.1. (DO)

1878. Transplantation of shells. Nature 18 (30 May): 120–1. F1783 It is well known that animals and plants inhabiting freshwater have, as a general rule, a very wide distribution; yet each river system, with all the pools and lakes in connection with it, seems completely cut off from every other system of the same country. Still more complete is the separation between the freshwaters of distinct continents or of islands; nevertheless they often possess freshwater species in common. In my “Origin of Species”1 I have suggested various means of transportal; but as few facts on this head are positively known, the case given in the adjoined letter of a living Unio,2 which had caught one of the toes of a duck’s foot |121| between its valves, and was secured in the act of being transported, seems to me well worth recording. Charles Darwin

1878. Memorial to the Vice-Chancellor respecting the Examination

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Dear Sir—The following case will, I think, prove of interest to you, as it corroborates your belief that freshwater shells are sometimes transplanted by the agency of aquatic birds. In the sketch I have endeavoured to give you a correct idea of the way in which the shell was attached to the duck’s foot. It was given to me by Mr. H. L. Newcomb, who shot the bird, which was a blue-winged teal (Querquedula discors), while flying, near the Artichoke river at West Newbury, Mass., September 6, 1877. The shell, the common mussel, or clam (Unio complanatus), is a very abundant species, being found in nearly all the rivers and ponds of the Atlantic slope. How long the shell had been attached is only a matter of conjecture, but it had abraded the skin of the bird’s toe, and left quite an impression. It was living when the bird was shot. It would have undoubtedly been transplanted to some pond or river, perhaps miles from its original home, had the bird not been shot, and might then have propagated its kind. Arthur H. Gray3 Danversport, Mass., May 8 To C. Darwin, Esq.

1 2 3

Origin, chapter 12. See also Darwin 1882, F1802 (p. 486). Freshwater pearly mussels. Arthur H. Gray, amateur naturalist.

1878. [Memorial to the Vice-Chancellor respecting the Examination in Greek in the Previous Examination]. Cambridge University Reporter (7 December): 206–7. F1939 Pembroke College Lodge. December 3, 1878. The following Memorial has been received by the Vice-Chancellor,1 and is published by him for the information of the Senate: To the Reverend the Vice-Chancellor, and the Council of the Senate, of the University of Cambridge. We, the undersigned, Considering the fact that the present regulation, according to which a knowledge of Greek is required from all Candidates for the Previous Examination at Cambridge, has the effect of excluding a large and increasing number of able and deserving students from the benefits of a University Education, |207| Respectfully pray that the Authorities of the University will be pleased to take into consideration some means whereby Candidates for an Honour Degree may be relieved from the obligation of passing an Examination in Greek. C. Darwin. [The other 37 names are omitted]

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1

1879. Fritz Müller on a frog having eggs on its back

John Power (1818–80). This memorial was discussed by the University Senate which approved a Grace on 20 March 1879 for the appointment of a Syndicate to consider the memorial and its implications. (Reporter 25 March 1879.) A report was not published until March 1880. The memorial was one of many in long and circuitous debate about University reforms. It was reprinted in The Times (9 December 1878): 6.

1879. Fritz Müller on a frog having eggs on its back—on the abortion of the hairs on the legs of certain caddis-flies, &c. Nature 19 (20 March): 462–3. F1784 Several of the facts given in the following letter from Fritz Müller, especially those in the third paragraph, appear to me very interesting. Many persons have felt much perplexed about the steps or means by which structures rendered useless under changed conditions of life, at first become reduced, and finally quite disappear. A more striking case of such disappearance has never been published than that here given by Fritz Müller. Several years ago some valuable letters on this subject by Mr. Romanes (together with one by me) were inserted in the columns of Nature.1 Since then various facts have often led me to speculate on the existence of some inherent tendency in every part of every organism to be gradually reduced and to disappear, unless in some manner prevented. But beyond this vague speculation I could never clearly see my way. As far, therefore, as I can judge, the explanation suggested by Fritz Müller well deserves the careful consideration of all those who are interested on such points, and may prove of widely extended application. Hardly anyone who has considered such cases as those of the stripes which occasionally appear on the legs and even bodies of horses and apes—or of the development of certain muscles in man which are not proper to him, but are common in the Quadrumana2—or again, of some peloric flowers—will doubt that characters lost for an almost endless number of generations, may suddenly reappear. In the case of |463| natural species we are so much accustomed to apply the term reversion or atavism to the reappearance of a lost part that we are liable to forget that its disappearance may be equally due to this same cause. As every modification, whether or not due to reversion, may be considered as a case of variation, the important law or conclusion arrived at by the mathematician Delbœuf,3 may be here applied; and I will quote Mr. Murphy’s condensed statement (“Habit and Intelligence,” 1879, p. 241)4 with respect to it: “If in any species a number of individuals, bearing a ratio not infinitely small to the entire number of births, are in every generation born with any particular variation which is neither beneficial nor injurious to its possessors, and if the effect of the variation is not counteracted by reversion, the proportion of the new variety to the original form will constantly increase until it approaches indefinitely near to equality.” Now in the case advanced by Fritz Müller the cause of the variation is supposed to be atavism

1879. Fritz Müller on a frog having eggs on its back

425

to a very remote progenitor, and this may have wholly prevailed over any tendency to atavism to more recent progenitors; and of such prevalence analogous instances could be given. Charles Darwin5

1

2 3 4 5

George John Romanes (1848–94), Canadian-born zoologist and psychologist who worked at University College London and Oxford. He was one of the youngest and most important of CD’s scientific colleagues and friends. Romanes 1874a and 1874b and Darwin 1873, F1762 (p. 382). Quadrumana = primates with four ‘hands’, i.e. apes and monkeys. Joseph Rémi Léopold Delboeuf (1831–96), Belgian mathematician, philosopher and psychologist. Delbœuf 1877. Joseph John Murphy (1827–94), American naturalist and evolutionist who was sceptical of the sufficiency of natural selection. Murphy 1879. Müller’s 900 word 21 January 1879 letter is omitted here, Cal: 11839. (DO) It described a frog living in the leaves of a Bromelia bearing eggs on its back. The woodcut of the frog is from a photograph. Müller described the legs of four species of caddis-fly pupae living on rocks near waterfalls or in Bromelia leaves which lacked the hairs used to aid in swimming of other caddis-fly pupae. Müller suggested the loss was not due to natural selection but instead to atavism.

426

[Report of conversation at Down]. In Francisque Sarcey. 1879

1879. Rats and water-casks. Nature 19 (27 March): 481. F1785 Mr. Nicols says, in Nature, vol xix. p. 433:—1 “A ship’s carpenter told me that, in the old days, before the use of iron tanks on board ship became general, the rats used to attack the water-casks, cutting the stave so thin that they could suck the water through the wood without actually making a hole in it. If any one could substantiate this it would have an important bearing on the question under consideration.”

Capt. Wickham,2 when First Lieutenant on board H.M.S. Beagle, told me that when he was a midshipman it was his duty, on one of the king’s ships to see that certain vessels on deck were always kept full of water, in order to prevent the rats gnawing holes through the water casks, and that through such holes nearly all the water in a cask would leak away. Charles Darwin

1 2

Arthur Nicols, author of numerous popular zoological and travel books. Nicols 1879. John Clement Wickham (1798–1864), First Lieutenant on the second (CD’s) voyage of the Beagle and CD’s favourite officer on board.

1879. [Extract from a letter to Grant Allen]. In Allen, G., Colour in nature. Nature 19 (24 April): 581. F2004 “The contrast,” he says, “in the colour of the birds in Patagonia” (where he had just noticed “the sombre aspect of nature”), “and on the bright green flower decked plains of La Plata is very striking.”1

1

This is an extract from Cal: 11891. Grant was writing in response to criticisms of Grant 1879 by Wallace 1879.

[Report of conversation at Down]. In Francisque Sarcey. 1879. Lettres de Londres: X. Le XIX Siècle (19 June). F20001 C’est dommage de s’en aller, disait-il à Barbier, lorsque’on a encore tant de choses à faire. A mesure que j’avance dans l’étude de la nature, je decouvre des horizons plus vastes, et je sens bien que je n’aurai pas le temps d’y atteindre.

1880. [Letter to Samuel Butler on Kosmos and Erasmus Darwin]

427

Je n’ai pu comprendre tout ce que vous avez dit à mes filles, et qui les a tant amusées. Mais elles me le répèteront ce soir, et j’aurai beaucoup de plaisir à vous entendre. English translation: “It is a pity to have to go,” he said to Barbier, “when one has still so many things to do. As I proceed in the study of nature, I discover vaster horizons, and I feel that I shall not have time to reach them.” “I have not been able to understand what you said to the ladies, and which amused them so much, but they will repeat it to me to-night, and I shall have much pleasure in hearing you in that way.”2

1

2

Francisque Sarcey (1827–99), French journalist and dramatic critic whom George Darwin referred to as a ‘fat vulgar little frenchman’ in his recollection of this visit with Edmond Barbier (d. 1880), the French translator of CD’s works. DAR112.B24–B29 (DO) Translation from: A peep at Mr. Darwin. 1879. Trewman’s Exeter Flying Post (5 November): 6.

1880. [Letter to Samuel Butler on Kosmos and Erasmus Darwin]. In Butler, S. Unconscious memory. London: D. Bogue, pp. 72–3. F1992 January 3, 1880. My Dear Sir,1—Dr. Krause, soon after the appearance of his article in Kosmos, told me that he intended to publish it separately and to alter it considerably, and the altered MS. |73| was sent to Mr. Dallas2 for translation. This is so common a practice that it never occurred to me to state that the article had been modified; but now I much regret that I did not do so. The original will soon appear in German, and I believe will be a much larger book than the English one; for, with Dr. Krause’s consent, many long extracts from Miss Seward3 were omitted (as well as much other matter), from being in my opinion superfluous for the English reader. I believe that the omitted parts will appear as notes in the German edition. Should there be a reprint of the English Life I will state that the original as it appeared in Kosmos was modified by Dr. Krause before it was translated. I may add that I had obtained Dr. Krause’s consent for a translation, and had arranged with Mr. Dallas before your book was announced. I remember this because Mr. Dallas wrote to tell me of the advertisement.—I remain, yours faithfully, C. Darwin.

1

Samuel Butler (1835–1902), novelist who became a critic of Darwinism in the 1870s. Ernst Krause’s short biography of CD’s grandfather was published in Kosmos in February 1879. A revised version, which referred indirectly to Butler 1879 (published in May), was translated into English and published

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2 3

1880. [Letter on purportedly carnivorous bees]

by CD in November. Butler was outraged by the implication that the alterations appeared in the German original. See The Darwin–Butler Controversy. Appendix 2 in Autobiography, pp. 167–229. Cal: 12396. William Sweetland Dallas (1824–90), entomologist and author who translated Fritz Müller, Für Darwin (1869) and Erasmus Darwin. Anna Seward (1747–1809), author and poet who published a biography of Erasmus Darwin in 1804. Seward 1804.

1880. Darwin’s reply to a vegetarian. Herald of Health and Journal of Physical Culture n.s. 31: 180. F1984 The following letter was received from Charles Darwin in answer to one written to him by a person1 who saw in the theory of evolution, as set forth by this great naturalist, evidence in favor of vegetarianism. We find it in a German vegetarian journal, and translate: Dear Sir.—I have so many letters to answer that mine to you must be brief. Nevertheless, this has not the significance it would have if I had given the subject of vegetarian diet special attention. The only evidence in my opinion which would be of any value, would be the statistics in regard of the amount of labor performed in countries where the population lived on a different diet. I have always been astonished at the fact that the most extraordinary workers I ever saw, viz., the laborers in the mines of Chili, live exclusively on vegetable food, which includes many seeds of the leguminous plants. On the other hand, the Gauchos are a very active people, and live almost entirely on flesh. Further, it appears to me to be good evidence that in tropical Africa an extraordinary craving exists, which increases to a necessity at times, to eat flesh, though I presume that the seeds of leguminous plants abound there, for the earth nut is extensively cultivated. Charles Darwin.

1

CD’s 25 February 1879 letter was addressed to the wealthy German economist, publisher and socialist Karl Höchberg (1853–85), then living in Switzerland. The letter originally appeared in Vereins-Blatt für Freunde der natürlichen Lebensweise. Vegetarische Monatsschrift. The original letter is at the American Philosophical Society. See Cal: 11902.

1880. [Letter on purportedly carnivorous bees]. In Packard, A. S. Jr., Moths entrapped by an Asclepiad plant (Physianthus) and killed by honey bees. American Naturalist 14, no. 1 (January): 50. F1953 Down, Beckenham, Kent, Nov. 23d. I never heard of bees being in any way carnivorous, and the fact is to me incredible. Is it possible that the bees opened the bodies of the Plusia to suck the nectar contained in their stomachs? Such a degree of reason would require repeated confirmation and would be very wonderful. I hope that you or some one will attend to the subject.1

1880. Fertility of hybrids from the common and Chinese goose

1

429

Only CD’s letter to Alpheus Spring Packard (1839–1905), American zoologist, entomologist and founder of the American Naturalist, 1867, is included here. (DO) See Cal: 12333. Reprinted in Botanical Gazette 5, No. 2 (February): 17–20.

1880. Fertility of hybrids from the common and Chinese goose. Nature 21 (1 January): 207. F1786 In the “Origin of Species” I have given the case, on the excellent authority of Mr. Eyton,1 of hybrids from the common and Chinese goose (Anser cygnoides)2 being quite fertile inter se; and this is the most remarkable fact as yet recorded with respect to the fertility of hybrids, for many persons feel sceptical about the hare and the rabbit. I was therefore glad to have the opportunity of repeating the trial, through the kindness of the Rev. Dr. Goodacre,3 who gave me a brother and sister hybrid from the same hatch. A union between these birds was therefore a shade closer than that made by Mr. Eyton, who coupled a brother and sister from different hatches. As there were tame geese at a neighbouring farm-house, and as my birds were apt to wander, they were confined in a large cage; but we found out after a time that a daily visit to a pond (during which time they were watched) was indispensable for the fertilisation of the eggs. The result was that three birds were hatched from the first set of eggs; two others were fully formed, but did not succeed in breaking through the shell; and the remaining first-laid eggs were unfertilised. From a second lot of eggs two birds were hatched. I should have thought that this small number of only five birds reared alive indicated some degree of infertility in the parents, had not Mr. Eyton reared eight hybrids from one set of eggs. My small success may perhaps be attributed in part to the confinement of the parents and their very close relationship. The five hybrids, grandchildren of the pure parents, were extremely fine birds, and resembled in every detail their hybrid parents. It appeared superfluous to test the fertility of these hybrids with either pure species, as this had been done by Dr. Goodacre; and every possible gradation between them may be commonly seen, according to Mr. Blyth4 and Capt. Hutton in India,5 and occasionally in England. The fact of these two species of geese breeding so freely together is remarkable from their distinctness, which has led some ornithologists to place them in separate genera or sub-genera. The Chinese goose differs conspicuously from the common goose in the knob at the base of the beak, which affects the shape of the skull; in the very long neck with a stripe of dark feathers running down it; in the number of the sacral vertebræ; in the proportions of the sternum;* markedly in the voice or “resonant trumpeting,” and, according to Mr. Dixon,† in the period of incubation, though this has been denied by others.6 In the wild state the two species inhabit different regions.‡ I am aware that Dr. Goodacre is inclined to believe that Anser cygnoides is only a variety of the common goose raised under domestication. He * † ‡

Charlesworth’s “Mag. of Nat. Hist.,” vol. iv., new series, 1840, p. 90. T. C. Eyton, “Remarks on the Skeletons of the Common and Chinese Goose”. [Eyton 1840.] “Ornamental and Domestic Poultry,” 1848, p. 85. Dr. L. v. Schrenck’s “Reisen und Forschungen im Amur-Land,’ B. i. p. 457. [Schrenk 1858.]

430

1880. The sexual colours of certain butterflies

shows that in all the above indicated characters, parallel or almost parallel variations have arisen with other animals under domestication. But it would, I believe, be quite impossible to find so many concurrent and constant points of difference as the above, between any two domesticated varieties of the same species. If these two species are classed as varieties, so might the horse and ass, or the hare and rabbit. The fertility of the hybrids in the present case probably depends to a limited degree (1) on the reproductive power of all the Anatidæ7 being very little affected by changed conditions, and (2) on both species having been long domesticated. For the view propounded by Pallas,8 that domestication tends to eliminate the almost universal sterility of species when intercrossed, becomes the more probable the more we learn about the history and multiple origin of most of our domesticated animals. This view, in so far as it can be trusted, removes a difficulty in the acceptance of the descent-theory, for it shows that mutual sterility is no safe and immutable criterion of specific difference. We have, however, much better evidence on this head, in the fact of two individuals of the same form of heterostyled plants, which belong to the same species as certainly as do two individuals of any species, yielding when crossed fewer seeds than the normal number, and the plants raised from such seeds being, in the case of Lythrum salicaria,9 as sterile as are the most sterile hybrids. Charles Darwin Down, December 15

1 2 3 4 5 6 7 8 9

Thomas Campbell Eyton (1809–80), ornithologist, specialist in skeletal variation and Cambridge contemporary of CD’s. Origin, p. 253. CD discussed the Chinese goose in Variation 1: 237, Descent 2: 114, 129 and Natural selection 427, 431, 433, 439–440. Francis Burges Goodacre (1829–85), clergyman and naturalist. Edward Blyth (1810–73), zoologist and Zoological Curator of Museum of Asiatic Society of Bengal, Calcutta, 1844–62. Thomas Hutton, Captain in the Bengal Army; invalided in 1841; author of works on natural history and scriptural geology in the 1850s and 1860s. Edmund Saul Dixon (1809–93), clergyman and poultry fancier. From 1854 he published under the pseudonym Eugene Sebastian Delamer. Dixon 1848. The family that includes ducks, geese and swans. Pallas 1780. See Darwin 1864, F1731 (p. 345).

1880. The sexual colours of certain butterflies. Nature 21 (8 January): 237. F1787 Dr. Schulte,1 of Furstenwalde, has called my attention to the beautiful colours which appear on all four wings of a butterfly, the Diadema bolina, when looked at from one point of view. The two sexes of this butterfly differ widely in colour. The wings of the male, when viewed from behind, are black with six marks of pure white, and they present an elegant appearance; but when viewed in front, in which position, as Dr. Schulte remarks, the male would be seen by the female when approaching her, the white marks are surrounded by a halo of beautiful

1880. The sexual colours of certain butterflies

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blue. Mr. Butler,2 also showed me in the British Museum an analogous and more striking case in the genus Apatura, in which the sexes likewise differ in colour, and in the males the most magnificent green and blue tints are visible only to a person standing in front. Again with Ornithoptera3 the hind wings of the male are in several species of a fine golden yellow, but only when viewed in front; this holds good with O. magellanus but here we have a partial exception, as was pointed out to me by Mr. Butler, for the hind wings when viewed from behind change from a golden tint into a pale iridescent blue. Whether this latter colour has any special meaning could be discovered only by some one observing the behaviour of the male in its native home. Butterflies when at rest close their wings, and their lower surfaces, which are often obscurely tinted, can then alone be seen; and this it is generally admitted, serves as a protection. But the males, when courting the females, alternately depress and raise their wings, thus displaying the brilliantly coloured upper surface; and it seems the natural inference that they act in this manner in order to charm or excite the females. In the cases above described this inference is rendered much more probable, as the full beauty of the male can be seen by the female only when he advances towards her. We are thus reminded of the elaborate and diversified manner in which the males of many birds, for instance the peacock, argus pheasant, &c., display their wonderful plumage to the greatest advantage before their unadorned friends.4 The consideration of these cases leads me to add a few remarks on how far consciousness necessarily comes into play in the first acquirement of certain instincts, including sexual display; for as all the males of the same species behave in the same manner whilst courting the female, we may infer that the display is at least now instinctive. Most naturalists appear to believe that every instinct was at first consciously performed; but this seems to me an erroneous conclusion in many cases, though true in others. Birds, when variously excited, assume strange attitudes and ruffle their feathers; and if the erection of the feathers in some particular manner were advantageous to a male whilst courting the female, there does not seem to be any improbability in the offspring which inherited this action being favoured; and we know that odd tricks and new gestures performed unconsciously are often inherited by man. We may take a different case (which I believe has been already advanced by some one), that of young ground birds which squat and hide themselves when in danger immediately after emerging from the egg; and here it seems hardly possible that the habit could have been consciously acquired just after birth without any experience. But if those young birds which remained motionless when frightened, were oftener preserved from beasts of prey than those which tried to escape, the habit of squatting might have been acquired without any consciousness on the part of the young birds. This reasoning applies with special force to some young wading and water birds, the old of which do not conceal themselves when in danger. Again a hen partridge when there is danger flies a short distance from her young ones and leaves them closely squatted; she then flutters along the ground as if crippled, in the wonderful manner which is familiar to almost every one; but differently from a really wounded bird, she makes herself conspicuous. Now it is more than doubtful whether any bird ever existed with sufficient intellect to think that if she imitated the actions of an injured bird she would draw away a dog or other enemy from her young ones; for this

1880. The Omori shell mounds

432

presupposes that she had observed such actions in an injured comrade and knew that they would tempt an enemy to pursuit. Many naturalists now admit that, for instance, the hinge of a shell has been formed by the preservation and inheritance of successive useful variations, the individuals with a somewhat better constructed shell being preserved in greater numbers than those with a less well constructed one; and why should not beneficial variations in the inherited actions of a partridge be preserved in like manner, without any thought or conscious intention on her part any more than on the part of the mullusc, the hinge of whose shell has been modified and improved independently of consciousness. Charles Darwin Down, December 16, 1879

1 2 3 4

Eduard Schulte. Arthur Gardiner Butler (1844–1925), entomologist and ornithologist employed by the British Museum. Large tropical Southeast Asian and Australasian butterflies known for their strong sexual dimorphism with females considerably larger and less brightly coloured than males. See Descent 2.

1880. The Omori shell mounds. Nature 21 (15 April): 561. F1788 I have received the enclosed letter from Prof. Morse,1 with a request that I should forward it to you. I hope that it may be published, for the article in Nature2 to which it refers seemed to me to do very scant justice to Prof. Morse’s work.3 I refer more especially to the evidence adduced by him on cannibalism by the ancient inhabitants of Japan—on their platycnemic tibiæ4—on their degree of skill in ceramic art—and beyond all other points, on the changes in the molluscan fauna of the islands since the period in question. It is a remarkable fact, which incidentally appears in Prof. Morse’s memoir, that several Japanese gentlemen have already formed large collections of the shells of the Archipelago, and have zealously aided him in the investigation of the prehistoric mounds. This is a most encouraging omen of the future progress of science in Japan.5 Charles Darwin Down, Beckenham, Kent, April 9

1 2 3 4

Edward Sylvester Morse (1838–1925), American invertebrate zoologist who worked for a time in Japan. Written by Frederick Victor Dickins (1838–1915), physician and plant collector who collected plants in Japan. Dickins 1880. Morse 1879. Flattened shin-bones, believed to be a characteristic of early humans.

1880. Sir Wyville Thomson and natural selection 5

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Morse’s letter, in which he complains about the criticisms of his memoir by Dickins, is omitted. (DO) The Darwin–Morse letter to Nature instigated a series of further letters in Nature and The American naturalist. See Morse 1880.

1880. Encouragement of original research: the Darwin prize. The Midland Naturalist: The journal of the Associated Natural History, Philosophical, and Archæological Societies and Field Clubs of the Midland Counties 3, no. 32 (August): 181. F1993 I request that you will be so good as to inform the members of the Committee that their wish to name the Medal after me is a very great honour, which I gladly accept. It is particularly pleasing to me to have my name connected, in however indirect a manner, with a scheme for advancing Science—the study of which has been my chief source of happiness throughout life.1

1

On 15 July 1880 the Committee of Management of the Midland union of natural history societies approved ‘That a Prize, (to be called, by permission of Mr. Charles Darwin, F. R. S., “The Darwin Prize,”) of the value of £10, to include a Gold or Bronze “Darwin Medal,” at the option of the successful candidate, be given annually for a paper indicating original research upon a subject within the scope of the Societies in the Union, contributed by a member for publication in the Journal of the Union [The Midland Naturalist].’ Ibid. p. 182. See Cal: 12653, 12660 , 12660a. Partially reprinted in Nature 22 (29 July 1880): 299.

1880. Sir Wyville Thomson and natural selection. Nature 23 (11 November): 32. F1789 I am sorry to find that Sir Wyville Thomson1 does not understand the principle of natural selection, as explained by Mr. Wallace and myself. If he had done so, he could not have written the following sentence in the Introduction to the Voyage of the Challenger:—“The character of the abyssal fauna refuses to give the least support to the theory which refers the evolution of species to extreme variation guided only by natural selection.”2 This is a standard of criticism not uncommonly reached by theologians and metaphysicians, when they write on scientific subjects, but is something new as coming from a naturalist. Prof. Huxley demurs to it in the last number of Nature;3 but he does not touch on the expression of extreme variation, nor on that of evolution being guided only by natural selection. Can Sir Wyville Thomson name any one who has said that the evolution of species depends only on natural selection? As far as concerns myself, I believe that no one has brought forward so many observations on the effects of the use and disuse of parts, as I have done in my “Variation of Animals and Plants under Domestication”; and these observations were made for this special object. I have likewise there adduced a considerable body of facts, showing the direct action of external conditions on organisms; though no doubt since my books were published much has been learnt on this head. If Sir Wyville Thomson were to visit the yard of a breeder, and saw all his cattle or sheep almost absolutely true, that is closely similar,

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1880. Black sheep

he would exclaim: “Sir, I see here no extreme variation; nor can I find any support to the belief that you have followed the principle of selection in the breeding of your animals.” From what I formerly saw of breeders, I have no doubt that the man thus rebuked would have smiled and said not a word. If he had afterwards told the story to other breeders, I greatly fear that they would have used emphatic but irreverent language about naturalists. Charles Darwin Down, Beckenham, Kent, November 5

1

2 3

Charles Wyville Thomson (1830–82), Scottish naturalist and oceanographer. Francis Darwin referred to this letter as ‘the only instance in which [CD] wrote publicly with anything like severity’. LL3: 242. It was reprinted in ML1: 388–89 with an additional paragraph. Thomson 1880, p. 50. Huxley 1880.

1880. [Letter of thanks to the Yorkshire Naturalists’ Union]. The naturalist 6, no. 65 (December): 67–8. F1969 Since the return of the deputation a letter has been received from Dr. Darwin by Mr. W. D. Roebuck,1 in which he writes: — The address which was presented to me is certainly one of the greatest |68| honours ever paid to a scientific man. It is admirably expressed, and the engrossing seems to me an exquisite work of art. I fear that I by no means deserve all that is said of me in the address; but it shows the great kindness and sympathy of the senders. Pray accept my best thanks for all the kind interest which you have shewn in the affair, and believe me, dear sir, yours faithfully, Charles Darwin.2

1 2

William Denison Roebuck (1851–1919), zoologist, secretary of the Yorkshire Naturalists’ Union and editor of the Naturalist. Only CD’s letter is included here. (DO) The preceding article recounts the visit of the deputation to Down House on 3 November. A report of the memorial, without CD’s letter, appeared in Nature (18 November 1880): 57.

1880. Black sheep. Nature 23 (30 December): 193. F1790 The following extract of a letter from Mr. Sanderson of Chislehurst,1 who permits me to publish it, seems worth placing on record. It relates to the former frequent appearance of spotted or black sheep in the Australian flocks, as long as animals thus coloured were of use to man, although they were never, as far as Mr. Sanderson knows, separately bred from, and certainly not in his own case. On the other hand, as soon as coloured sheep ceased to be of use they were no longer allowed to grow up, and their numbers rapidly decreased. I have elsewhere assigned reasons for the belief that the occasional appearance of dark-coloured or

1881. [Letter on the expression of the eye]

435

piebald sheep is due to reversion to the primeval colouring of the species. This tendency to reversion appears to be most difficult quite to eradicate, and quickly to gain in strength if there is no selection. Mr. Sanderson writes:—“In the early days before fences were erected and when shepherds had charge of very large flocks (occasionally 4000 or 5000) it was important to have a few sheep easily noticed amongst the rest; and hence the value of a certain number of black or partly black sheep, so that coloured lambs were then carefully preserved. It was easy to count ten or a dozen such sheep in a flock, and when one was missing it was pretty safe to conclude that a good many had strayed with it, so that the shepherd really kept count of his flock by counting his speckled sheep. As fences were erected the flocks were made smaller, and the necessity for having these spotted sheep passed away. Their wool also being of small value the practice soon grew of killing them off as lambs, or so young that they had small chance of breeding, and it surprised me how at the end of my sheep-farming experience of about eight years the percentage of coloured lambs produced was so much smaller than at the beginning. As the quantity of coloured wool from Australia seems to have much diminished, the above experience would appear to be general.” Charles Darwin

1

John Sanderson Sr., wool merchant and founder of Sanderson & Murray, Melbourne in 1854. See McLaren 1954.

1881. [Letter on the expression of the eye]. In Plumptre, C. J. King’s College lectures on elocution: or, The physiology and culture of voice and speech, and the expression of the emotions by language, countenance, and gesture … New ed. London: Trübner, pp. 290–1. F1994 Down, Beckenham, Kent. My Dear Sir, —I thank you for your very obliging letter, and for the information in regard to Delsarte’s2 views respecting the eyes. Although it is very easy to deceive one’s self on such a point, yet after reading over |291| what I have said, I cannot think that we are in error. Surely the different appearance of the eyes in hectic fever, and during great exhaustion to which Dr. Piderit3 alludes, cannot be accounted for simply by the position of eyelids and eyebrows. Could you not observe the eyes of some one looking grave, and then smiling? I will endeavour to do so. 1

I remain, my dear Sir, Yours faithfully, Charles Darwin. August 19th. [c. 1877] C. J. Plumptre, Esq.

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1881. [Extracts from two letters on the drift deposits near Southampton]

I am very glad to find that the opinion I [Plumptre] had formed is confirmed by so eminent an authority as Mr. Darwin.*

1 2 3

Charles John Plumptre (1818–87), barrister and writer on elocution. François Delsarte (1811–71), French musician and dramatic elocution teacher who claimed that the eyes alone could not reveal specific emotions only the object of them. Theodor Piderit (1826–1912), German physician who published on physiognomy. CD frequently cited Piderit 1867 in Expression.

1881. [Extracts from two letters on the drift deposits near Southampton]. In Geikie, J., Prehistoric Europe. A geological sketch. London: Edward Stanford, pp. 141–2. F1351 The origin of these gravels1 has always been a difficult question, but a suggestion which Mr. Darwin some years ago (1876) did me the honour to communicate gives what appears to be the true explanation of the somewhat puzzling phenomena. Having since had an opportunity of testing the value of the suggestion referred to, I have found it extremely helpful, and believe that my co-workers will agree with me in this opinion. Mr. Darwin, after remarking that his observations were made near Southampton, writes as follows: — “I need say nothing about the character of the drift there (which includes Palæolithic celts), for you have described its essential features in a few words (Great Ice Age, p. 506).2 It covers the whole country, even plain-like surfaces, almost irrespective of the present outline of the land. The coarse stratification has sometimes been disturbed; and I find that you allude to ‘the larger stones often standing on end,’ which is the point that struck me so much. Not only moderately-sized angular stones but small oval pebbles often stand vertically up, in a manner which I have never seen in ordinary gravel-beds. This fact reminded me of what occurs in my own neighbourhood in the stiff red clay, full of unworn flints, over the chalk, which is no doubt the residue left undissolved by rain-water. In this clay flints as long and as thin as my arm often stand perpendicularly up, and I have been told by the tank-diggers that it is their ‘natural position’! I presume that this position may safely be attributed to the differential movement of parts of the red clay, as it subsided very slowly from the dissolution of the underlying chalk, so that the flints arrange themselves in the lines of least resistance. The similar but less-strongly marked arrangement of the stones in the drift near Southampton makes me suspect that it also must have slowly subsided, and the notion has crossed my mind that during the commencement and height of the Glacial Period great beds of frozen snow accumulated over Southern England, and that during the summer gravel and stones were washed from the higher land over its surface, and in superficial channels. The larger streams may have cut right through the frozen snow, and |142| deposited gravel in lines at the bottom. But at each succeeding autumn, when the running-water failed, I imagine that the lines of drainage would have been filled up with blown snow, afterwards congealed; and that owing to the great surface-accumulations of snow it would be a mere chance whether the drainage, together with gravel and sand, would follow the same lines during the next summer. Thus, as *

Since this letter was written, now more than four years ago, Mr. Darwin has favoured me with another communication, stating that further observation has in no way altered his opinion.

1881. [Letter on subsidence in the Pacific]

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I apprehend, alternate layers of frozen snow and drift in sheets and lines would ultimately have covered the country to a great thickness, with lines of drift probably deposited in various directions at the bottom by the larger streams. As the climate became warmer the lower beds of frozen snow would have melted with extreme slowness, and during this movement the elongated pebbles would have arranged themselves more or less vertically. The drift would also have been deposited almost irrespective of the outline of the underlying land. When I viewed the country I could not persuade myself that any flood, however great, could have deposited such coarse gravel over the almost level platforms between the valleys.”

Mr. Darwin writes me again recently to say that subsequent observations near Southampton and elsewhere have only tended to strengthen him in his conclusion. Referring to the structure of his own neighbourhood (Beckingham, Kent), he says the chalk-platform slopes gently down from the edge of the escarpment (which is about 800 feet in height) towards the north, where it disappears below the Tertiary strata. “The beds of the large and broad valleys, and only of these, are covered with an immense mass of closely-packed, broken, and angular flints, in which mass remains of the musk-sheep and woolly elephant have been found. This great accumulation of unworn flints must therefore have been made when the climate was cold, and I believe it can be accounted for by the large valleys having been filled up to a great depth during a large part of the year with drifted frozen snow, over which rubbish from the upper parts of the platforms was washed by the summer rains and torrents, sometimes along one line and sometimes along another, or in channels cut through the snow all along the main course of the broad valleys.”

1 2

Gravel of the Pleistocene or Glacial Age. Although dated 1881, the book was issued in late 1880. James Geikie (1839–1915), Scottish geologist. See Cal: 10676 and 12663. Geikie 1874.

1881. [Letter on subsidence in the Pacific]. In Semper, K., The natural conditions of existence as they affect animal life. London: Kegan Paul, p. 456. F1952 October 2, 1879. My dear Professor Semper,1—I thank you for your extremely kind letter of the 19th and for the proof-sheets. I believe that I understand all, excepting one or two sentences where my imperfect knowledge of German has interfered. This is my sole excuse for the mistake which I made in the second edition of my Coral-book. Your account of the Pelew Islands is a fine addition to our knowledge on coral reefs. I have very little to say on the subject: even if I had formerly read your account and seen your maps, but had known nothing of the proofs of recent elevation, and of your belief that the islands have not since subsided, I have no doubt that I should have considered them as formed during subsidence. But I should have been much troubled in my mind by the sea not being so deep as it usually is round atolls, and by the reef on one side sloping so gradually beneath the sea; for this latter fact, as far as my memory serves me, is a very unusual and almost unparalleled case.

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I always foresaw that a bank at the proper depth beneath the surface would give rise to a reef which could not be distinguished from an atoll formed during subsidence. I must still adhere to my opinion that the atolls and barrier-reefs in the middle of the Pacific and Indian Oceans indicate subsidence; but I fully agree with you that such cases as that of the Pelew Islands, if of at all frequent occurrence, would make my general conclusions of very little value. Future observers must decide between us. It will be a strange fact if there has not been subsidence of the bed of the great oceans, and if this has not affected the forms of the coral reefs. Yours very sincerely, Charles Darwin.

1

Karl Gottfried Semper (1832–93), German zoologist who explored the Philippines, 1858–65 and professor of zoology, Würzburg, 1869–93.

1881. Movements of plants. Nature 23 (3 March): 409. F1791 Fritz Müller, in a letter from St. Catharina, Brazil, dated January 9, has given me some remarkable facts about the movements of plants. He has observed striking instances of allied plants, which place their leaves vertically at night, by widely different movements; and this is of interest as supporting the conclusion at which my son Francis and I arrived,1 namely, that leaves go to sleep in order to escape the full effect of radiation. In the great family of the Gramineæ2 the species in one genus alone, namely Strephium, are known to sleep, and this they do by the leaves moving vertically upwards; but Fritz Müller finds in a species of Olyra, a genus which in Enlicher’s “Genera Plantarum”3 immediately precedes Strephium, that the leaves bend vertically down at night. Two species of Phyllanthus (Euphorbiaceæ) grow as weeds near Fritz Müller’s house; in one of them with erect branches the leaves bend so as to stand vertically up at night. In the other species with horizontal branches, the leaves move vertically down at night, rotating on their axes, in the same manner as do those of the Leguminous genus Cassia. Owing to this rotation, combined with the sinking movement, the upper surfaces of the opposite leaflets are brought into contact in a dependent position beneath the main petiole; and they are thus excellently protected from radiation, in the manner described by us. On the following morning the leaflets rotate in an opposite direction, whilst rising so as to resume the diurnal horizontal position with their upper surface exposed to the light. Now in some rare cases Fritz Müller has observed the extraordinary fact that three or four, or even almost all the leaflets on one side of a leaf of this Phyllanthus rise in the morning from their nocturnal vertically dependent position into a horizontal one, without rotating, and on the wrong side of the main petiole. These leaflets thus project horizontally with their upper surfaces directed towards the sky, but partly shaded by the leaflets proper to this side. I have never before heard of a plant appearing to make a mistake in its movements; and the

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mistake in this instance is a great one, for the leaflets move 90° in a direction opposite to the proper one. Fritz Müller adds that the tips of the horizontal branches of this Phyllanthus curl downwards at night, and thus the youngest leaves are still better protected from radiation. The leaves of some plants, when brightly illuminated, direct their edges towards the light; and this remarkable movement I have called paraheliotropism. Fritz Müller informs me that the leaflets of the Phyllanthus just referred to, as well as those of some Brazilian Cassiæ, “take an almost perfectly vertical position, when at noon, on a summer day, the sun is nearly in the zenith. To-day the leaflets, though continuing to be fully exposed to the sun, now at 3 p.m. have already returned to a nearly horizontal position.” F. Müller doubts whether so strongly marked a case of paraheliotropism would ever be observed under the duller skies of England; and this doubt is probably correct, for the leaflets of Cassia neglecta, on plants raised from seed formerly sent me by him, moved in this manner, but so slightly that I thought it prudent not to give the case. With several species of Hedychium, a widely different paraheliotropic movement occurs, which may be compared with that of the leaflets of Oxalis and Averrhoa; for “the lateral halves of the leaves, when exposed to bright sunshine, bend downwards, so that they meet beneath the leaf.” Charles Darwin Down, Beckenham, February 22

1 2 3

Power of movement, chapter 6. Poaceae. Stephan Ladislaus Endlicher (1804–49), German botanist. Endlicher 1836–40.

1881. [Letter to Emily Talbot]. Social science.—Infant education. The Journal of Speculative Philosophy 15, no. 2 (April): 206–7. F1995 Beckenham, Kent, Railway Station, Orpington, S. E. R., July 19, 1881. Dear Madam:1 In response to your wish, I have much pleasure in expressing the interest which I feel in your proposed investigation on the mental and bodily development of infants. Very little is at present accurately known on this subject, and I believe that isolated observations will add but little to our knowledge; whereas, tabulated results from a very large number of observations systematically made would probably throw much light on the sequence and period of development of the several faculties. This knowledge would probably give a foundation for some improvement in our education of young children, and would show us whether the same system ought to be followed in all cases. I will venture to specify a few points of inquiry which, as it seems to me, possess some scientific interest. For instance, does the education of the parents influence the mental powers of their children at any age, either at a very early or somewhat more advanced stage?

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This could, perhaps, be learned by schoolmasters or mistresses, if a large number of children were first classed according to age and their mental attainments, and afterward in accordance with the education of their parents, as far as this could be discovered. As observation is one of the earliest faculties developed in young children, and as this power would probably be exercised in an equal degree by the children of educated and uneducated persons, it seems not impossible that any transmitted effect from education could be displayed only at a somewhat advanced age. It would be desirable to test statistically in a similar manner the truth of the often-repeated statement that colored children at first learn as quickly as white children, but that they afterward fall off in progress. If it could be proved that education acted not only on the individual, but by transmission on the race—this would be a great encouragement to all working on this all-important subject. It is well known that children sometimes exhibit at a very early age strong special tastes, for which no cause can be assigned, although occasionally |207| they may be accounted for by reversion to the taste or occupation of some progenitor; and it would be interesting to learn how far such early tastes are persistent and influence the future career of the individual. In some instances such tastes die away without apparently leaving any after-effect; but it would be desirable to know how far this is commonly the case, as we should then know whether it were important to direct, as far as this is possible, the early tastes of our children. It may be more beneficial that a child should follow energetically some pursuit of however trifling a nature, and thus acquire perseverance, than that he should be turned from it, because of no future advantage to him. I will mention one other small point of inquiry in relation to very young children which may possibly prove important with respect to the origin of language; but it could be investigated only by persons possessing an accurate musical ear. Children, even before they can articulate, express some of their feelings and desires by noises uttered in different notes. For instance, they make an interrogative noise and others of assent and dissent in different tones; and it would, I think, be worth while to ascertain whether there is any uniformity in different children in the pitch of their voices under various frames of mind. I fear that this letter can be of no use to you; but it will serve to show my sympathy and good wishes in your researches. I beg leave to remain, dear madam, yours faithfully, Charles Darwin. To Mrs. Emily Talbot.

1

Emily Fairbanks Talbot (1834–1900), American reformer and secretary of the Education Department of the American Social Science Association, Boston, Mass. A circular and register were issued by the Department soliciting answers to various questions. See Nature (28 April 1881): 617. Cal: 13249. Also published in E. Talbot ed., Papers on infant development. Education Department of the American Social Science Association, January, 1882. Boston: Tolman & White; extracts in Nature 24 (13 October): 565, F1797; ML2: 54 and elsewhere.

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1881. Mr. Darwin on vivisection. The Times (18 April): 10. F1352 The following letter has been addressed by Mr. Charles Darwin to Professor Holmgren,1 of Upsala, in answer to a request for an expression of his opinion on the question of the right to make experiments on living animals for scientific purposes—a question which is now being much discussed in Sweden:—2 Down, Beckenham, April 14, 1881. Dear Sir,—In answer to your courteous letter of April 7 I have no objection to express my opinion with respect to the right of experimenting on living animals. I use this latter expression as more correct and comprehensive than that of vivisection. You are at liberty to make any use of this letter which you may think fit, but if published I should wish the whole to appear. I have all my life been a strong advocate for humanity to animals, and have done what I could in my writings to enforce this duty. Several years ago, when the agitation against physiologists commenced in England, it was asserted that inhumanity was here practised and useless suffering caused to animals; and I was led to think that it might be advisable to have an Act of Parliament on the subject. I then took an active part in trying to get a Bill passed, such as would have removed all just cause of complaint, and at the same time have left physiologists free to pursue their researches—a Bill very different from the Act which has since been passed. It is right to add that the investigation of the matter by a Royal Commission proved that the accusations made against our English physiologists were false.3 From all that I have heard, however, I fear that in some parts of Europe little regard is paid to the sufferings of animals, and if this be the case I should be glad to hear of legislation against inhumanity in any such country. On the other hand, I know that physiology cannot possibly progress except by means of experiments on living animals, and I feel the deepest conviction that he who retards the progress of physiology commits a crime against mankind. Any one who remembers, as I can, the state of this science half a century ago must admit that it has made immense progress, and it is now progressing at an ever-increasing rate. What improvements in medical practice may be directly attributed to physiological research is a question which can be properly discussed only by those physiologists and medical practitioners who have studied the history of their subjects; but, as far as I can learn, the benefits are already great. However this may be, no one, unless he is grossly ignorant of what science has done for mankind, can entertain any doubt of the incalculable benefits which will hereafter be derived from physiology, not only by man, but by the lower animals. Look, for instance, at Pasteur’s4 results in modifying the germs of the most malignant diseases, from which, as it so happens, animals will in the first place receive more relief than man. Let it be remembered how many lives and what a fearful amount of suffering have been saved by the knowledge gained of parasitic worms through the experiments of Virchow5 and others on living animals. In the future every one will be astonished at the ingratitude shown, at least in England, to these benefactors of mankind. As for myself,

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permit me to assure you that I honour, and shall always honour, every one who advances the noble science of physiology. Dear Sir, yours faithfully, Charles Darwin. To Professor Holmgren.

1

2

3

4 5

Frithiof Holmgren (1831–97), Swedish professor of Physiology at Uppsala. CD’s letter was reprinted in Nature, the British Medical Journal and Jesse 1881. The letter provoked a response on 19 April in The Times by Frances Power Cobbe. CD responded to Cobbe with a letter to The Times on 22 April (Darwin 1881, F1793 (below)). Another respondent to CD’s letter was George Richard Jesse (1820–98), civil engineer and leading anti-vivisectionist, see Jesse 1881. See also LL3: 205–9 and Darwin 1881, F1799 (p. 451). The Swedish parliament was discussing legislation to regulate physiological and medical experimentation. Holmgren wrote to several eminent men of science for their views on vivisection or experimentation on living animals. CD gave evidence before the Royal Commission on the practice of subjecting live animals to experiments for scientific purposes in November 1875. See Darwin 1876, F1275 (p. 398). Louis Pasteur (1822–95), French chemist and microbiologist. Rudolf Carl Virchow (1821–1902), German physician, pathologist, medical reformer and politician.

1881. Mr. Darwin on vivisection. The Times (22 April): 11. F1793 Sir,—I do not wish to discuss the views expressed by Miss Cobbe1 in the letter which appeared in The Times of the 19th inst.; but as she asserts that I have “misinformed” my correspondent in Sweden2 in saying that “the investigation of the matter by a Royal Commission proved that the accusations made against our English physiologists were false,” I will merely ask leave to refer to some other sentences from the Report of the Commission.3 (1) The sentence—“It is not to be doubted that inhumanity may be found in persons of very high position as physiologists,” which Miss Cobbe quotes from page 17 of the report, and which, in her opinion, “can necessarily concern English physiologists alone and not foreigners,” is immediately followed by the words “We have seen that it was so in Majendie.”4 Majendie was a French physiologist who became notorious some half-century ago for his cruel experiments on living animals. (2) The Commissioners, after speaking of the “general sentiment of humanity” prevailing in this country, say (p. 10):—“This principle is accepted generally by the very highly educated men whose lives are devoted either to scientific investigation and education or to the mitigation or the removal of the sufferings of their fellow-creatures; though differences of degree in regard to its practical application will be easily discernible by those who

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study the evidence as it has been laid before us.” Again, according to the Commissioners (p. 10):—“The secretary of the Royal Society for the Prevention of Cruelty to Animals, when asked whether the general tendency of the scientific world in this country is at variance with humanity, says he believes it to be very different, indeed, from that of foreign physiologists; and while giving it as the opinion of the society that experiments are performed which are in their nature beyond any legitimate province of science, and that the pain which they inflict is pain which it is not justifiable to inflict even for the scientific object in view, he readily acknowledges that he does not know a single case of wanton cruelty, and that in general the English physiologists have used anæsthetics where they think they can do so with safety to the experiment.” I am, Sir, your obedient servant, Charles Darwin. April 21.

1 2 3 4

Frances Power Cobbe (1822–1904), Anglo-Irish journalist, social reformer and founder of the Anti-Vivisection Society, 1875. Frithiof Holmgren, see Darwin 1881, F1352 (p. 441). Cobbe’s letter appeared in The Times on 19 April. Cobbe replied in The Times on 23 April. CD’s letter was reprinted in LL3: 207–8. See Darwin 1876, F1275 (p. 398). François Magendie (1783–1855), French physiologist and pioneer in experimental physiology.

1881. The movements of leaves. Nature 23 (28 April): 603–4. F1794 Fritz Mueller has sent me some additional observations on the movements of leaves, when exposed to a bright light. Such movements seem to be as well developed and as diversified under the bright sun of Brazil, as are the well-known sleep or nyctitropic movements of plants in all parts of the world. This result has interested me much, as I long doubted whether paraheliotropic movements were common enough to deserve to be separately designated. It is a remarkable fact that in certain species these movements closely resemble the sleep movements of allied forms. Thus the leaflets of one of the Brazilian Cassiæ assume when exposed to sunshine nearly the same position as those of the not distantly allied Hæmatoxylon when asleep, as shown in Fig. 153 of “The Movements of Plants.”1 Whereas the leaflets of this Cassia sleep by moving down and rotating on their axes, in the same peculiar manner as in so many other species of the genus. Again, with an unnamed species of Phyllanthus, the leaves move forwards at night, so that their midribs then stand nearly parallel to the horizontal branches from which they spring; but when they are exposed to bright sunshine they rise up vertically, and their upper surfaces come into contact, as they are opposite. Now this is the position which the leaves of another species, namely Phyllanthus compressus, assume when they go to sleep at night. Fritz Müller states that the paraheliotropic movements of the leaves of a Mucuna,2 a large twining Papilionaceous plant, are strange and inexplicable;

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the leaflets sleep by hanging vertically down, but under bright sunshine the petiole rises vertically up, and the terminal leaflet rotates by means of a pulvinus through an angle of 180°, and thus its upper surface stands on the same side with the lower surfaces of the lateral leaflets. Fritz Müller adds, “I do not understand the meaning of this rotation of the terminal leaflet, as even without such a movement it would be apparently equally well protected against the rays of the sun. The leaflets, also, on many of the leaves on the same plant assume various other strange positions.” With one species of Desmodium,3 presently to be mentioned as sleeping in a remarkable manner, the leaflets rise up vertically when exposed to bright sunshine, and the upper surfaces of the lateral leaflets are thus brought into contact. The leaves of Bauhinia grandiflora go to sleep at an unusually early hour in the evening, and in the manner described at p. 373 of “The Movements of Plants,” namely, by the two halves of the same leaf rising up and coming into close contact: now the leaves of Bauhinia Brasiliensis do not sleep, as far as Fritz Müller has seen, but they are very sensitive to a bright light, and when thus exposed the two halves rise up and stand at 45° or upwards above the horizon. Fritz Müller has sent me some cases, in addition to those given in my former letter of March 3,4 of the leaves of closely-allied plants which assume a vertical position at night by widely different movements; and these cases are of interest as indicating that sleepmovements have been acquired for a special purpose. We have just seen that of two species of Bauhinia the leaves of one sleep conspicuously, while those of a second species apparently |604| do not sleep it all. The leaves of Euphorbia jacquiniæ flora depend vertically at night whereas those of a dwarfish Brazilian species rise vertically up at night. The leaves of this Euphorbia stand opposite one another—a position which is rather rare in the genus, and the rising movement may be of service to the plant, as the upper surfaces of the opposite leaves mutually protect one another by coming into contact. In the genus Sida the leaves of two species rise, while those of a third Brazilian species sink vertically down at night. Two species of Desmodium are common plants near Fritz Müller’s house: in one the leaflets move simply downwards at night, but in the other not only do the three leaflets move vertically down, while the main petiole rises vertically up, as is likewise the case with D. gyrans, but in addition the lateral leaflets rotate so as to stand parallel with the terminal leaflet, behind which they are more or less completely hidden. This, as far as I have seen, is a new kind of nyctitropic movement, but it leads to a result common to several species, namely, that of packing the three leaflets closely together and placing them in a vertical position. Charles Darwin Down, Beckenham, Kent, April 14

1

Fig. 153 from Power of movement (1880), p. 369. ‘Hæmatoxylon Campechianum: A, branch during daytime; B, branch with leaves asleep, reduced to two-thirds of natural scale.’

1881. [Letter to G. E. Mengozzi on design in nature]

2 3 4

445

A genus of climbing vines and shrubs. Common names include tick-trefoil, tick clover and beggar lice. Darwin 1881, F1791 (p. 438).

1881. [Letter to G. E. Mengozzi on design in nature]. Roma Etrusca no. 2 (15 July): 10. F1970 Londra, ottobre 1880. Caro signore, Vi ringrazio per le vostre estremamente cortesi lettere. Il tentare una risposta alle questioni che Voi mi avete fatto l’onore d’indirizzarmi (per quanto io le comprenda) sarebbe una lunga impresa, e io sono in debole salute e il lavoro mi affaticherebbe molto. Ma avendo con l’ultima vostra compreso più chiaramente la questione, io volentieri risponderò ad essa come meglio potrò.—Io non credo cho nessun essere organico dimostra evidenza di disegno. Se Voi vi date la pena di leggere le ultime due pagine della mia Variazione degli Animali e delle Piante sotto la domesticazione,1 Voi in parte rinverrete le mie ragioni. Ma sebbene nessun organismo può mostrare disegno, ciò in nessun modo esclude la credenza nell’esistenza di un amoroso Creatore di tutto le cose. L’evidenza di un tale Creatore bisogna che sia indagata, come a me sombra, ancora fuori dei limiti della Scienza Fisica. Il problema è uno dei più difficili. Dall’altro lato io so che molti uomini, le cui menti sono incomparabilmente più chiare e profonde della mia (ed io non ho mai atteso abbastanza alle questioni metafisiche e religiose) sono convinti che l’evidenza dell’esistenza di Dio è quasi evidente per se stessa. Mi fo premura accusarvi ricevimento e ringraziarvi per il dono del vostro magnifico volume sulla Filosofia della Medicina.2 Di più vi prego ad essere cosi buono da portare alla vostra Società, La Scuola Italica, residente in Roma, i molti miei cordiali ringraziamenti pel grande onore che in si distinta maniera mi conferiscono. Pregovi di accettare i mici

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migliori ringraziamenti per le vostro molto amabili espressioni inverso di me, mentre io rimango, caro Signora, con molto rispetto, Professor Mengozzi M. D.3 Vostro fedelmente e molto obbligato Carlo Darwin. English translation: London, October 1880. Dear Sir, I thank you for your extremely kind letters. An attempt at a reply to the questions that you have done the honour of addressing to me (in so far as I understand them) would be a lengthy task, and I am in weak health and the work would tire me greatly. Yet having read your last letter and understanding more clearly the nature of your question, I will gladly respond to it as best as I am able. I do not believe that any organic form of life exhibits evidence of design. If you would take the trouble to read the final two pages of my Variations in Animals and Plants under domestication,4 you will find, in part, my reasons. But even if no organism can exhibit design, this does not in any way exclude the belief in a divine Creator of all things. Evidence of such a Creator would needs be investigated, which it seems to me, is still beyond the limits of the Natural Sciences. The problem is one of the most difficult. On the other hand I know many men possessed of intellect far clearer and deeper than mine (and I have never attended enough to metaphysical and religious questions) that are convinced that the evidence of the existence of God is almost self-evident. I was delighted to receive and thank you for the gift of your most magnificent volume on the Philosophy of Medicine.5 May I also ask you to be so kind as to extend my most cordial thanks to your Society, La Scoula Italica, residing in Rome, for the great honour which they have in so distinguished a manner conferred on me. I pray you accept my sincere thanks for your most courteous letters, and I remain, dear Sir, with much respect, Yours faithfully and much obliged, Charles Darwin. Professor Mengozzi M. D.6

1 2 3 4 5 6

Variation 2: 431–2. See Cal: 12778f. Mengozzi 1869. Giovanni Ettore Mengozzi, Italian homeopathic physician and writer. Variation 2: 431–2. Mengozzi 1869. Giovanni Ettore Mengozzi, Italian homeopathic physician and writer.

1881. Inheritance. Nature 24 (21 July): 257. F1795 The tendency in any new character or modification to reappear in the offspring at the same age at which it first appeared in the parents or in one of the parents, is of so much importance

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in reference to the diversified characters proper to the larvæ of many animals at successive ages, that almost any fresh instance is worth putting on record. I have given many such instances under the term of “inheritance at corresponding ages.”1 No doubt the fact of variations being sometimes inherited at an earlier age than that at which they first appeared—a form of inheritance which has been called by some naturalists “accelerated inheritance”—is almost equally important, for, as was shown in the first edition of the “Origin of Species,” all the leading facts of embryology can be explained by these two forms of inheritance, combined with the fact of many variations arising at a somewhat late stage of life.2 A good instance of inheritance at a corresponding age has lately been communicated to me by Mr. J. P. Bishop of Perry,3 Wyoming, N.Y., United States:—The hair of a gentleman of American birth (whose name I suppress)4 began to turn grey when he was twenty years old, and in the course of four or five years became perfectly white. He is now seventy-five years old, and retains plenty of hair on his head. His wife had dark hair, which, at the age of seventy, was only sprinkled with grey. They had four children, all daughters, now grown to womanhood. The eldest daughter began to turn grey at about twenty, and her hair at thirty was perfectly white. A second daughter began to be grey at the same age, and her hair is now almost white. The two remaining daughters have not inherited the peculiarity. Two of the maternal aunts of the father of these children “began to turn grey at an early age, so that by middle life their hair was white.” Hence the gentleman in question spoke of the change of colour of his own hair as “a family peculiarity.” Mr. Bishop has also given me a case of inheritance of another kind, namely, of a peculiarity which arose, as it appears, from an injury, accompanied by a diseased state of the part. This latter fact seems to be an important element in all such cases, as I have elsewhere endeavoured to show. A gentleman, when a boy, had the skin of both thumbs badly cracked from exposure to cold, combined with some skin disease. His thumbs swelled greatly, and remained in this state for a long time. When they healed they were misshapen, and the nails ever afterwards were singularly narrow, short, and thick. This gentleman had four children, of whom the eldest, Sarah, had both her thumbs and nails like her father’s; the third child, also a daughter, had one thumb similarly deformed. The two other children, a boy and girl, were normal. The daughter, Sarah, had four children, of whom the eldest and the third, both daughters, had their two thumbs deformed; the other two children, a boy and girl, were normal. The great-grandchildren of this gentleman were all normal. Mr. Bishop believes that the old gentleman was correct in attributing the state of his thumbs to cold aided by skin disease, as he positively asserted that his thumbs were not originally misshapen, and there was no record of any previous inherited tendency of the kind in his family. He had six brothers and sisters, who lived to have families, some of them very large families, and in none was there any trace of deformity in their thumbs. Several more or less closely analogous cases have been recorded; but until within a recent period every one naturally felt much doubt whether the effects of a mutilation or injury were ever really inherited, as accidental coincidences would almost certainly occasionally occur. The subject, however, now wears a totally different aspect, since Dr. Brown-Séquard’s5 famous experiments proving that guinea-pigs of the next generation were affected by

1881. Rolleston memorial

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operations on certain nerves. Mr. Eugène Dupuy6 of San Francisco, California, has likewise found, as he informs me, that with these animals “lesions of nerve-trunks are almost invariably transmitted.” For instance, “the effects of sections of the cervical sympathetic on the eyes are reproduced in the young, also epilepsy (as described by my eminent friend and master, Dr. Brown-Séquard) when induced by lesions of the sciatic nerve.” Mr. Dupuy has communicated to me a still more remarkable case of the transmitted effects on the brain from an injury to a nerve; but I do not feel at liberty to give this case, as Mr Dupuy intends to pursue his researches, and will, as I hope, publish the results. Charles Darwin July 13

1 2 3 4 5 6

There are numerous references to ‘inheritance at corresponding ages’ in Origin, Variation and Descent. Origin p. 448 ff. Irving Prescott Bishop (1849–1913), American school science teacher, Perry, Wyoming County, New York, 1878–85. See Cal: 13137. E. B. Jones of Auburn New York. Charles Edouard Brown-Séquard (1817–94), French physiologist. Brown-Séquard 1860. Eugène Dupuy, French-born American neurologist.

1881. Rolleston memorial. The Times (5 August): 9. F1957 In pursuance of a resolution at a preliminary meeting held at the house of Dr. A. B. Shepherd, a General Committee is being formed for the purpose of Founding a Prize or Scholarship in Memory of the late Professor Rolleston.1 The following gentlemen among others have already allowed their names to appear in support of the proposed Memorial. A complete list will be published later, as well as a list of subscribers to the Fund.

Preliminary List […] Charles Darwin, Esq. [The other 70 names are omitted.] Subscriptions will be received by the Hon. Secs. at 17, Great Cumberland place, W.; or by the Treasurer, Edward Chapman, Esq., Frewen Hall, Oxford. Hon. Secs. C. W. Mansell-Moullin, M.D. Theodore D. Acland, M.B., A. P. Thomas, M.A.,

1

George Rolleston (1829–81), Linacre professor of anatomy and physiology, Oxford University, 1860–81.

1881. Mr. Darwin on Dr. Hahn’s discovery of fossil organisms in meteorites

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1881. Mr. Darwin on Dr. Hahn’s discovery of fossil organisms in meteorites. Science 2, no. 61 (27 August): 410. F1929 Dr. Hahn’s1 discovery, of which an elaborate account was given in no. 50 of Science,2 has stirred up a lively discussion of this highly interesting subject. Dr. Hahn has taken steps to enable Prof. von Quenstedt,3 the renowned Tübingen geologist, and all others who expressed the desire to examine his microscopic preparations. It is understood that all those who have availed themselves of the opportunity thus offered have become convinced of the genuineness of Dr. Hahn’s discovery. It is very interesting to note the position taken by the greatest of living evolutionists in this controversy, if it can still be called such. Charles Darwin, on receipt of Dr. Hahn’s work, wrote to him: “ … It seems to be very difficult to doubt that your photographs exhibit organic structure …,” and furthermore: “… your discovery is certainly one of the most important.” Not content with the mere presentation of his work, Dr. Hahn visited the veteran zoologist and brought his preparations to him for inspection. No sooner had Mr. Darwin peered through the microscope on one of the finest specimens when he started up from his seat and exclaimed: “Almighty God! what a wonderful discovery! Wonderful!” And after a pause of silent reflection he added: “Now reaches life down!”4 The latter remark no doubt refers to the proof furnished by Dr. Hahn’s discovery that organisms can reach our planet from celestial space. It is an acknowledgment of the relief Mr. Darwin must have felt in not being forced to a belief in a primeval “generatio equivoca.”5 As was suggested in the paper referred to, “the Richter-Thomson hypothesis6 of the origin of life on the earth has become a tangible reality!” R.7

1

2 3 4

Otto Hahn (1828–1904), German lawyer and amateur palaeontologist in Reutlingen, BadenWürttemberg, Germany who asserted that he had discovered microscopic fossils in meteorites in Hahn 1880. Hahn sent a copy to CD in December 1880. See Cal: 12917. Hahn became prominent during the Eozoon canadense controversy. CD referred to Eozoon as evidence for the antiquity of life in Origin 4th ed., p. 371 (and later eds). Hahn had earlier sent CD a copy of Hahn 1879. A draft of CD’s 20 December 1880 reply is in DAR251, Cal: 12929F. In which CD wrote ‘If you succeed in convincing several judges as trustworthy as Professor Quenstedt, you will certainly have made one of the most remarkable discoveries ever recorded.’ Rachel 1881. Friedrich August Quenstedt (1809–89), professor of mineralogy and geology, University of Tübingen. No evidence has been found for the interview in the Stadtsarchiv Reutlingen, Germany nor in the diaries of CD or Emma Darwin. The geologist Thomas George Bonney (1833–1923) wrote to Francis(?) Darwin (Cal: 13591) enquiring if the report of his father’s reactions to Hahn’s microscope slides was true. A letter from CD to Bonney (now lost) denied the story. Bonney thanked CD (Cal: 13663) for the denial and remarked that Hahn could not distinguish between organic and inorganic structures.

1881. Leaves injured at night by free radiation

450 5 6

7

Spontaneous generation. Referring to the views of the German physician H. E. Richter and Sir William Thomson (Lord Kelvin) that living cells must be the only source for subsequent living cells and that these might travel from planet to planet inside meteorites or comets (Richter 1865; Thomson 1871). George W. Rachel, American physician, and popular science writer.

1881. Mr. Darwin on mosquitoes. The Times (5 September): 10. F1948 A scientific gentleman of South Kensington,1 observing the numerous reports of the appearance of mosquitoes in England during the summer, wrote last week to Mr. Darwin, asking him whether he thought these insects were all imported and whether the professor thought that an exceptionally hot month might not have developed the English gnat into the mosquito. The following is Professor Darwin’s reply: — Down, Beckenham, Kent, Sept. 1.—Dear Sir,—I am sorry I cannot answer your question. The Tiputidæ, or gnat family, is a very difficult one and not well known. No trustworthy evidence has been advanced of the introduction or appearance in this country of a new species; but it seems to me probable that some English species have lately increased in number.—Dear Sir, yours faithfully,—C. Darwin.

1

Astley Paston Price (1826–86), consulting chemist in London. Price wrote to CD 30 August [1881], see Cal: 13306.

1881. Leaves injured at night by free radiation. Nature 24 (15 September): 459. F1796 Fritz Müller, in a letter to me from Sta. Catharina in Brazil, dated August 9, supports the view which I have advanced with respect to leaves placing themselves in a vertical position at night, during their so-called sleep, in order to escape being chilled and injured by radiation into the open sky.1 He says: “We have had last week some rather cold nights (2° to 3° C. at sunrise), and these have given me a new confirmation of your view on the meaning of the nyctitropic movements of plants. Near my house there are some Pandanus trees,2 about a dozen years old; the youngest terminal leaves stand upright, whereas the older ones are bent down so as to expose their upper surfaces to the sky. These young leaves, though of course the most tender, are still as fresh and green as before; on the contrary, the older ones have suffered from the cold, and have become quite yellowish. Again, the leaves of Oxalis sepium were observed by me to sleep in a very imperfect manner during the summer, even after the most sunny days; but now, in winter, every leaflet hangs down in a perpendicular position during the whole night.” It is a new fact to me that leaves should sleep in a more or less perfect manner at different seasons of the year. Charles Darwin 1 2

Power of movement. Screw pine.

1881. The parasitic habits of Molothrus

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1881. The parasitic habits of Molothrus. Nature 25 (17 November): 51–2. F1798 In the “Origin of Species” I adopted the view maintained by some writers, that the cuckoo lays her eggs in other birds’ nests, owing to her habit of laying them at intervals of two or three days; for it could hardly fail to be disadvantageous to her, more especially as she has to migrate at a very early period, to have young birds of different ages and eggs all together in the same nest.1 Nevertheless this occurs with the non-parasitic North American cuckoo. If it had not been for this latter case, it might have been argued that the habit of the common cuckoo to lay her eggs at much longer intervals of time than do most other birds, was an adaptation to give her time to search for foster parents. The Rhea or South American ostrich is believed likewise to lay her eggs at intervals of two or three days, and several hens deposit their eggs in the same nest on which the male sits; so that one hen may almost be said to be parasitic on another hen. These facts formerly made me very curious to learn how the several species of Molothrus,2 which are parasitic on other birds in very varying degrees, laid their eggs; and I have just received a letter from Mr. W. Nation,3 dated Lima, September 22, 1881, giving me information on this head. He says that he has there kept in confinement for a long time Molothrus perpurascens, and has likewise observed its habits in a state of nature. It is a resident species of Western Peru, and lays its eggs exclusively in the nests of a sparrow (Zonotrichia), starling (Sturnella bellicosa), and a pipit (ænthus chu). He then proceeds: “The eggs of the sparrow are very much like those of the Molothrus in size and colour. The eggs of the starling are larger and somewhat different in colour; while the eggs of the pipit are very different both in size and colour. Generally one egg of the Molothrus is found in a nest, but I have found as many as six. The young Molothrus does not always eject its foster-brothers; for I have seen a young one nearly fully feathered in a nest with two young |52| starlings. I have also found two young birds of the Molothrus nearly fully feathered in the nest of a starling; but in this instance the young starlings had been ejected from the nest.” He then states that he had long kept in confinement a male and female of this species of Molothrus, which are now six years old. The hen began to lay at the age of two years, and has laid each time six eggs, which is the number laid by Icterus,4 a near ally of Molothrus. The dates on which the eggs were laid this year are as follows:—February 1, 6, 11, 16, 21, and 26; so that there was an interval of exactly four clear days between the laying of each egg. Later in the season she laid six additional eggs, but at much longer intervals and irregularly, viz. on March 8, April 6 and 13, May 1, 16, and 21. These interesting facts, observed by Mr. Nation in relation to a bird so widely distinct from the cuckoo as is the Molothrus, strongly support the conclusion that there is some close connection between parasitism and the laying of eggs at considerable intervals of time. Mr. Nation adds that in the genus Molothrus, out of every three young birds he has invariably found two to be males; whereas with Sturnella, which lays only three eggs, two of the young birds are, without any exception, females. Charles Darwin Down, Beckenham, Kent, November 7

452

1 2 3 4

1882. Prefatory notice to Studies in the theory of descent

Origin pp. 216–18. Cowbirds. William Nation (1826–1907), botanist who lived and taught in Peru, 1862–80. Orioles.

1881. Mr. Charles Darwin and the defence of science. British Medical Journal 2 (3 December): 917. F1799 The following is an extract from a letter of Mr. Darwin to Dr. Lauder Brunton, dated November 19th. Dear Dr. Lauder Brunton,—I saw in some paper that there would perhaps be a subscription to pay Dr. Ferrier’s legal expenses in the late absurd and wicked prosecution.1 As I live so retired, I might not hear of the subscription, and I should regret beyond measure not to have the pleasure and the honour of showing my sympathy and admiration of Dr. Ferrier’s researches… …

1

In November 1881 David Ferrier (1843–1928), physician and neurophysiologist, was charged with infringing the Vivisection Act by the Victoria Street Society for the Protection of Animals. Ferrier was innocent and the case was dismissed. See the British Medical Journal (19 November 1881), The Times (18 November 1881) and ML 2: 437–41 where more of this letter is reproduced. Cal: 13490.

1882. Prefatory notice. In Weismann, A., Studies in the theory of descent. With notes and additions by the author: Translated and edited, with notes, by Raphael Meldola F. C. S.: With a prefatory notice by Charles Darwin, LL.D., F.R.S. 2 vols. London: Sampson Low, Marston, Searle, & Rivington. vol. 1, pp. [v]–vi. F1414 The present work by Professor Weismann,1 well known for his profound embryological investigations on the Diptera, will appear, I believe, to every naturalist extremely interesting and well deserving of careful study. Any one looking at the longitudinal and oblique stripes, often of various and bright colours, on the caterpillars of Sphinx-moths, would naturally be inclined to doubt whether these could be of the least use to the insect; in the olden time they would have been called freaks of Nature. But the present book shows that in most cases the colouring can hardly fail to be of high importance as a protection. This indeed was proved experimentally in one of the most curious instances described, in which the thickened anterior end of the caterpillar bears two large ocelli or eye-like spots, which give to the creature so formidable an appearance that birds were frightened away. But the mere explanation of the colouring of these caterpillars is but a very small part of the merit of the work. This mainly consists in the light thrown on the |vi| laws of variation and of inheritance by the facts given and discussed. There is also a valuable discussion on classification, as founded on characters displayed at different ages by animals belonging to the same

1882. The action of carbonate of ammonia on chlorophyll-bodies

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group. Several distinguished naturalists maintain with much confidence that organic beings tend to vary and to rise in the scale, independently of the conditions to which they and their progenitors have been exposed; whilst others maintain that all variation is due to such exposure, though the manner in which the environment acts is as yet quite unknown. At the present time there is hardly any question in biology of more importance than this of the nature and causes of variability, and the reader will find in the present work an able discussion on the whole subject, which will probably lead him to pause before he admits the existence of an innate tendency to perfectibility. Finally, whoever compares the discussions in this volume with those published twenty years ago on any branch of Natural History, will see how wide and rich a field for study has been opened up through the principle of Evolution; and such fields, without the light shed on them by this principle, would for long or for ever have remained barren. Charles Darwin.

1

August Friedrich Leopold Weismann (1834–1914), German zoologist, Darwinist and professor of zoology, Freiburg, 1866–1912, who proposed the theory of the continuity of the germ-plasm. This was a translation of Weismann 1875–6.

1882. The action of carbonate of ammonia on chlorophyll-bodies. By Charles Darwin, LL.D., F.R.S. [Read by Francis Darwin 6 March] Journal of the Linnean Society of London. Botany 19: 262–84. F1801 In my ‘Insectivorous Plants’1 I have described, under the term of aggregation, a phenomenon which has excited the surprise of all who have beheld it.* It is best exhibited in the tentacles or so-called glandular hairs of Drosera, when a minute particle of any solid substance, or a drop of almost any nitrogenous fluid, is placed on a gland. Under favourable circumstances the transparent purple fluid in the cells nearest to the gland becomes in a few seconds or minutes slightly turbid. Soon minute granules can be distinguished under a high power, which quickly coalesce or grow larger; and for many hours afterwards oval or globular, or curiously-shaped masses of a purple colour and of considerable size may be observed sending out processes or filaments, dividing, coalescing, and redividing in the most singular manner, until finally one or two solid spheres are formed which remain motionless. The moving masses include vacuoles which change their appearance. (I append here three figures of aggregated masses copied from my son Francis’s paper,† showing the forms assumed.) After aggregation has been partially effected, the layer of protoplasm lining the walls of the cells may be seen with singular clearness flowing in great waves; and my son observed similarly flowing threads of protoplasm which connected together the grains of *

†

Pfeffer, in his recent admirable work ‘Pflanzenphysiologie’ (B. ii. 1881, p. 248), [Wilhelm Friedrich Philipp Pfeffer (1845–1920), German botanist. Pfeffer 1881.] speaks of the phenomenon as being in many respects interesting; and Cohn writes (“Die Pflanze,” Vortrãge aus dem Gebiete der Botanik, 1882, p. 361) in still stronger terms. [Cohn 1882.] Quart. Journ. Micr. Sci. vol. xvi. 1876, p. 309. [F. Darwin 1876.]

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chlorophyll. After a time the minute colourless particles which are imbedded in the flowing protoplasm are drawn towards and unite with the aggregated masses; so that the protoplasm on the walls being now rendered quite transparent is no longer visible, though some is still present, and still flows, as may be inferred from the occasional transport of particles in the cell-sap. The granules withdrawn from the walls, together probably with some matter derived from the flowing protoplasm and from the cell-sap, often form a colourless, or very pale purple, well-defined layer of considerable thickness, which surrounds the previously aggregated and now generally |263| spherical dark-purple masses.

Fig. 1. Cells in a tentacle of Drosera rotundifolia, showing aggregated masses after the action of carbonate of ammonia. Some of the masses with vacuoles.

Fig. 2. Aggregated masses undergoing redissolution. b, same cell as a, but masses drawn at a later period.

The surrounding layers or zones consist of solid matter, more brittle than the central parts of the aggregated masses, as could be seen when they were crushed beneath a cover-glass. It may be added that there is no à priori |264| improbability in some of the protoplasm being withdrawn, together with the imbedded granules, from the walls; for the whole of the protoplasm within the hairs of Tradescantia contracts, when subjected to great cold, into several spheres, and these, when warmed again, spread themselves out over the walls.*

*

Van Tieghem, ‘Traité de Botanique,’ 1882, p. 596. [Philippe Édouard Léon van Tieghem (1839–1914), French botanist. van Tieghem 1884, appeared in parts between 1881–83.] See also p. 528, on masses of protoplasm floating freely within the cavities of cells. Sachs (‘Physiologie Végétale,’ p. 74) [Sachs 1868.] and Kühne (‘Das Protoplasma,’ p. 103) have likewise seen small freely-floating masses of protoplasm in the hairs of Tradescantia and Cucurbita which undergo amœboid changes of form. [Wilhelm Friedrich Kühne (1837–1900), German physiologist. Kühne 1864.]

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Fig. 3. a, b, c, d, e, the same cell drawn at successive short intervals of time, showing the aggregated masses produced by an infusion of raw meat. The changes of form occurred so rapidly that it was impossible to copy the appearance of the whole cell at a given moment.

The process of aggregation commences in the gland which is stimulated, and slowly travels down the whole length of the tentacle, and even into the disk of the leaf, but very much more slowly than the impulse which causes the basal part of the tentacle to bend inwards. It is a more interesting fact that when the glands on the disk are stimulated, they transmit some influence to the glands of the surrounding tentacles, which undergo throughout their whole length the process of aggregation, although they themselves have not been directly stimulated; and this process may be compared with a reflex action in the nervous system of an animal. After a few days the solid aggregated masses are redissolved. The process of redissolution commences in the cells at the bases of the tentacles and travels slowly upwards; therefore in a reversed direction to that of aggregation. Considering that the aggregated masses are solid enough to be broken into fragments, their prompt redissolution is a surprising fact; and we are led to suspect that some ferment must be generated in the disk of the leaf, and be transmitted up the tentacles. The double process of aggregation and of redissolution takes place every time that a leaf of Drosera catches an insect. Aggregation is a vital process—that is, it cannot occur in cells after their death. This was shown by waving leaves* for a few minutes in water at a temperature of 65°.5 C. (150° F.), or even at a somewhat lower temperature, and then immersing them in a rather strong solution of carbonate of ammonia, which does not cause in this case any aggregation, although the most powerful of all known agents. If a tentacle is slightly crushed, so that many of the cells are ruptured, though they still retain much of their purple fluid contents, no aggregation occurs in them when they are similarly immersed, notwithstanding |265| that in closely

*

‘Insectivorous Plants,’ p. 58.

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1882. The action of carbonate of ammonia on chlorophyll-bodies

adjoining cells which have not been killed, as could be seen by the protoplasm still flowing round the walls, aggregation ensued. So that the process is quite arrested by the death of a cell, and it is much delayed if a leaf, before being immersed in the solution, is kept for some time in carbonic acid; and this agrees with the well-known fact that protoplasm retains its activity only as long as it is in an oxygenated condition. When tentacles, including recently aggregated masses, are suddenly killed or much injured by being dipped into hot water, or by being irrigated with alcohol, acetic acid, or a solution of iodine, the aggregated masses suddenly disintegrate and disappear, leaving only a little fine granular matter; but this disintegration does not occur with the more solid masses which have been aggregated for some time. From the several foregoing considerations, from the aggregated masses being of an albuminoid nature (as shown by the tests employed by my son Francis, and as is admitted by Pfeffer),* and from their incessant, long-continued amœba-like movements, I formerly concluded that not only these masses, but that the minute globules which first appear in the cell-sap consist, at least in part, of living and spontaneously moving protoplasm. And I feel compelled to adhere to my original conclusion, notwithstanding that such high authorities as Cohn and Pfeffer believe that the aggregated masses consist merely of condensed cell-sap. The movements of the masses, I presume, are considered by these botanists to be of the same nature as those curious ones described by Beneke2 as occurring in myelin when immersed in water and in a solution of sugar.† From the doubts thus thrown upon my original conclusion, it seemed to me advisable to observe the action of carbonate of ammonia on grains of chlorophyll, as it is generally admitted that these consist of modified protoplasm. The grains not only change their positions under certain circumstances, which may be due merely to the movements of the streaming protoplasm in which they are imbedded, but they likewise have the power of changing their shapes, as has been recently proved by Stahl.‡ |266| They are also capable of self-division.§ Now, if it can be shown that a solution of carbonate of ammonia tends to cause the grains of living chlorophyll to become confluent one with another and with previously aggregated masses, this fact would support the conclusion that the aggregated masses consist, at least in part, of living protoplasm, to which their incessant movements may be attributed. And it is the object of the present paper to show that chlorophyll-bodies are thus acted on in certain cases by carbonate of ammonia. The fact by itself possesses some little interest, independently of the light which it throws on the remarkable phenomenon of aggregation.

* † ‡ §

‘Pflanzenphysiologie’ Bd. ii. p. 248. [Pfeffer 1881.] ‘Studien über das Vorkommen…von Gallenbestandtheil’ (Giessen, 1862). See his interesting papers in the ‘Botanische Zeitung,’ 1880, pp. 298–413, and more especially p. 361. [Ernst Stahl (1848–1919), German botanist. Stahl 1880.] Van Tieghem, ‘Traité de Botanique,’ 1882, p. 493.

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Dionæa muscipula.—The effects of carbonate of ammonia are best shown in the case of young, small, and thin leaves produced by starved plants, as these are quickly penetrated by the solution. Transverse sections of such leaves and of others were made before they had been immersed;* and the cells, including those of the epidermis, could easily be seen to be packed with grains of chlorophyll. It is, however, necessary to avoid examining a leaf which has ever caught an insect; for in this case many of the cells will be found filled with yellowish matter instead of with chlorophyll-grains. Several leaves were left for different lengths of time in solutions of different strengths; but it will suffice to describe a few cases. A small thin leaf was immersed for 24 hours in a solution of 7 parts of the carbonate to 1000 of water, and transverse sections were then examined. The cells near the margin of the leaf, throughout its whole thickness, did not now exhibit a single chlorophyll-grain, but in their place masses of transparent yellowish-green matter of the most diversified shapes. They resembled those of Drosera shown at fig. 3, if we suppose several of them to be pressed lightly together. Some of the masses in the same cell were connected by extremely fine threads. Spheres of more solid matter were sometimes included within the oddly-shaped greenish masses. The contrast in appearance between these sections and those taken from one corner of the same leaf before it had been immersed was wonderfully great. The sections were then clarified by being left for some time in alcohol, but not a grain of chlorophyll could be seen; whereas the fresh slices similarly clarified exhibited |267| with the utmost plainness the now colourless grains. The oddly-shaped green masses exhibited none of the movements so conspicuous in the case of Drosera; but this could hardly have been expected after the injury caused by slicing; and the leaves are much too opaque to be examined without the aid of sections. Some other sections from the same immersed leaf presented a rather different appearance, as they contained much extremely fine granular green matter, which became pale brown after being kept in alcohol. No chlorophyll-grains could be seen in any of these sections. After adding iodine (dissolved in water with iodide of potassium), many particles of starch became visible by being coloured blue; but none were present in the first described section. Some of the larger rounded aggregated masses were coated with blue particles. Others were quite free of such particles, and were coloured by the iodine bright orange. A superficial slice was taken from a fresh leaf, showing the upper epidermic and glandular surface, and all the cells abounded with large grains of chlorophyll. But with a leaf which had been immersed for 24 hours in a solution of carbonate of ammonia (7 to 1000), a similar section presented a wonderfully different aspect; no chlorophyll-grains could be seen. Some of the cells contained one or two transparent yellowish spheres, which, it could hardly be doubted, had been formed by the fusion of previously-existing chlorophyll-grains. Other cells contained very fine brownish granular matter, and this apparently had been deposited from the cell-sap with its colour changed. This granular matter was generally aggregated

*

These sections and many others were made for me by my son Francis, to whom I owe much information and other assistance.

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into one or two either separate or more or less confluent spherical balls, having a rough surface. Sometimes a dark-brown granular sphere was surrounded by a zone of paler granular matter. In other cases brown granular spheres lay in the centre of transparent yellow spheres. In one case a sphere of this latter kind, with two others consisting exclusively of the yellowish transparent matter, were observed in the same cell. In other cases the brown balls were surrounded merely by an extremely narrow border of transparent matter. It appears that in these cases the granular matter had first been deposited, and then had become more or less aggregated into balls; and that afterwards the yellowish transparent matter, formed by the fusion of the modified chlorophyll-grains, had aggregated either round the granular matter or into independent spherical and oddly-shaped masses. |268| Transverse sections of other immersed leaves presented various appearances. In one cell a central transparent sphere was surrounded by a halo of brown granular matter, and this again by a zone of the transparent matter, and such matter quite filled some adjoining cells. In the cells of another leaf there were, throughout its whole thickness, yellow, greenish, orange, pale or very dark-brown spheres. Some of these latter spheres had a dark centre, which was so hard that it was cracked by pressure, and the line of separation from the surrounding zone of paler matter was distinct. Two brown spheres were in one case included within the same transparent sphere. Gradations seemed to show that the opaque granular matter ultimately passed into dark-coloured transparent matter. In these same sections there were some colourless or yellowish highly-transparent small spheres, which, I believe, were merely much swollen chlorophyll-grains. One, two, or more of such grains, while still partly retaining their outlines, sometimes clung to the darker granular spheres. When there were only one or two of them thus clinging, they assumed the shapes of half- or quarter-moons. It appeared as if such swollen grains when completely confluent had often given rise to the pale zones surrounding the granular spheres. The pale zones were rendered still more transparent by acetic acid; and on one occasion they quite disappeared, after being left in the acid for 24 hours; but whether the matter was dissolved or had merely disintegrated was not ascertained. This acid produces the same effect on recently aggregated pale-coloured or almost colourless matter in the tentacles of Drosera. In one leaf a good many unaltered chlorophyll-grains could still be distinguished in some of the cells; and this occurred more frequently in the thickest part of the leaf, near the midrib, than elsewhere. In one section the chlorophyll-grains had run together, and formed in some of the cells narrow green rims round all four walls. In many sections, more especially in those in which the process of aggregation had not been carried very far, there was much extremely fine granular matter, which did not resemble smashed or disintegrated chlorophyllgrains, such as may often be seen in sections of ordinary leaves. This granular matter occasionally passed into excessively minute, transparent, more or less confluent globules. Judging from these several appearances, we may conclude that carbonate of ammonia first acts on the cell-sap, producing a granular |269| deposit of a pale brownish colour, and that this tends to aggregate into balls; that afterwards the grains of chlorophyll are acted on, some swelling up and becoming completely confluent, so that no trace of their original structure is left, and others breaking up into extremely fine greenish granular matter, which

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appears likewise to undergo aggregation. The final result is the formation of balls of brown, and sometimes reddish, granular matter, often surrounded by zones, more or less thick, of yellowish or greenish, or almost colourless transparent matter. Or, again, spheres, ovals, and oddly-shaped masses are formed, consisting exclusively of this transparent yellowish-green matter. As soon as the process of aggregation has been thoroughly carried out, not a grain of chlorophyll can be seen. Drosera rotundifolia.—It is advisable to select for observation pale reddish leaves, as the dark-red ones are too opaque; and the process of aggregation does not go on well in the small completely green leaves which may sometimes be found. The tentacles, which are merely delicate prolongations of the leaf, are from their transparency well fitted for observation. In sections of the disks of fresh leaves, the cells of the epidermis are seen to abound with grains of chlorophyll, as well as those of the underlying parenchyma. The bases of the exterior tentacles and the part immediately beneath the glands are generally coloured pale green from the presence of chlorophyll-grains in the parenchyma; and some occur throughout the whole length of the longer tentacles, but are not easily seen on account of the purple cell-sap. Sometimes the epidermal cells of the longer tentacles include chlorophyll-grains; but this is rather a rare event. The footstalks of the short tentacles on the disk are bright green, and invariably abound with grains of chlorophyll. A pale leaf, in which the basal cells of the exterior tentacles contained numerous grains of chlorophyll, was left for 24 hours in a solution of only 2 parts of the carbonate to 1000 of water; and now innumerable greenish spheres, resembling oil in appearance, were present in these cells, and the ordinary chlorophyll-grains had in most places disappeared. Nevertheless in several cells some swollen grains were still distinct. Other cells contained fine granular or pulpy green matter collected into masses at one end. In a few other cells the chlorophyllgrains had run together, forming a continuous green rim with a sinuous outline attached to the walls. In fresh leaves the guard-cells of the |270| stomata include grains of chlorophyll; but these, after the leaf has been immersed in the carbonate, almost always become fused into a few nearly colourless spheres. Sections made from leaves which had been left for 22 hours in a solution of 4 to 1000 exhibited, in the upper and lower epidermal cells of the disk, and in the cells of the parenchyma near the bases of the exterior tentacles, greenish spheres; and in such cells there were no chlorophyll-grains, but they were still present in some few of the epidermal cells which did not contain aggregated masses, and they abounded in the parenchyma in the middle of the disk, where there were only a few green spheres. These sections were irrigated with the solution of iodine, and the green spheres became yellow; and many minute elliptical particles of starch, coloured blue, could now be seen. Such particles were not visible in the sections of fresh leaves, and I believe that they had been imbedded within the chlorophyll-grains, from which the enveloping protoplasm had been withdrawn to form the green spheres. One of the above leaves was left in the ammonia solution for three days, by which time it had become flaccid, being evidently killed. The numerous green spheres were blackened, but perfectly retained their outlines. No chlorophyll-grains could be seen, but many particles

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of starch. When leaves were left for some time in a solution of 7 to 1000, much pulpy green matter and innumerable spheres were sometimes formed, but no large aggregated masses; so that in these cases the solution appeared to have been too strong. The degree to which the grains of chlorophyll are acted on varies much from unknown causes; for in some tentacles, which exhibited strongly-marked aggregation after being left for 36 hours in the stronger solution, the grains could still be seen, but only after they had been cleared by immersion in acetic acid. A leaf was laid on a glass plate kept in a damp chamber, and two or three tentacles at one end were covered with thin glass, so as to prevent their bending, and were irrigated with the ammonia solution of 7 to 1000. After 24 hours and 48 hours these tentacles included many dark-purple aggregated masses; nevertheless plenty of chlorophyll-grains were still visible. In the disk of this leaf, however, near the bases of these tentacles, there were some spheres of a fine green tint, and others purple in the centre surrounded by a distinctly defined green zone; and in |271| most of the cells containing these spheres not a grain of chlorophyll could be distinguished. That the green surrounding zones had been derived from the chlorophyllgrains is, I think, certain; for the purple colour of the central spheres showed that the cell-contents had not been originally green. Other cells in these same sections included irregularly-shaped masses of a purplish-green colour; and these were observed slowly to change their forms in the usual manner. When acetic acid was added to them, the green transparent spheres and the zones of similar green matter round the purple spheres instantly disappeared, either from being dissolved or, as seems more probable, from being killed and suddenly disintegrating. On another occasion boiling water and alcohol produced the same effect on the spheres. Tentacles still retaining their chlorophyll-grains, but with many very pale-coloured homogeneous aggregated masses (which were seen in movement), were irrigated with acetic acid; and it was curious to observe how instantaneously they became filled with small transparent spheres. In a short time, however, the outlines of the larger masses were alone left; then these disappeared, and finally the small enclosed spheres. On the other hand, some dark-coloured solid aggregated spherical masses did not disappear when left for 24 hours in acetic acid. The effect of the ammonia solution (4 and 7 to 1000) on the epidermal cells of the upper surface of the disk was now more especially observed. In some cases all these cells which, as already stated, invariably contain many chlorophyll-grains, included after immersion in the solution only a single or several green transparent spheres; but more commonly the spheres were very dark purple or brown. Sometimes a central sphere, which was so solid that it could be cracked, was surrounded by a well-defined paler zone. Numerous gradations could be traced, showing that several small spheres and irregularly shaped globules often coalesce, and thus form the larger rounded masses. It was repeatedly observed that when the epidermal cells contained only one or two large spheres, not a single grain of chlorophyll could be seen. It is surprising that dark purple or brown or almost black spheres should be formed in the epidermal cells of green leaves; for before immersion the cell-contents were colourless, with the exception of the chlorophyll-grains; but the fact is less surprising when it is known that these cells turn more or less red as they grow old if they are exposed to a |272| bright light.

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In some of these leaves the basal cells of the longer exterior tentacles had become beautifully transparent from the aggregation of their contents into green or greenish-purple masses; and here no chlorophyll-grains could be seen; but in other parts of the same tentacles, where the aggregated masses were of a purple tint, the chlorophyll-grains were still plainly visible. Finally, it appears certain that in the leaves of Drosera the grains of chlorophyll, if left long enough in a weak solution of the carbonate, sometimes break up and form translucent greenish globules, which are much smaller than the original chlorophyll-grains; and that these, by coalescing, form larger masses, which again coalesce into a few spheres or into a single one. In other cases the chlorophyll-grains swell and coalesce without having previously broken up into globules. During these various changes the aggregated masses often become coloured by the modified cell-sap, more especially in the case of the epidermal cells; or they may form a zone round the already aggregated cell-sap, in which case a dark central sphere is surrounded by a less dark or by a light-green transparent zone of matter. It remains to be considered whether the grains of chlorophyll, after complete fusion or aggregation, are ever reformed and reassume their normal positions on the walls of the cells. Although the purple aggregated masses within the tentacles are soon redissolved, the cells becoming refilled with transparent purple fluid, it by no means follows that the chlorophyllgrains should be reformed; and such a capacity would be an interesting point. To ascertain whether this occurred, drops of a weak solution of carbonate of ammonia (2 to 1000) were daily placed during 5 days on several leaves on a growing plant; but, to my surprise, the tentacles remained after the first day expanded, with their glands bright red and copiously secreting, and they exhibited little aggregation. Large drops of a solution of 4 to 1000 were next placed on three reddish leaves, fresh drops being added in about 18 hours. After an interval of 41½ hours from the time when the drops were first placed on the leaves, three short central tentacles on one leaf were examined, and the cells were seen to be filled with quickly moving aggregated masses, and not one grain of chlorophyll could be distinguished. In 66 hours after the drops had been given the leaves were well syringed with water; and now the central tentacles of a second leaf were examined, in |273| which there was much aggregated matter and no chlorophyll-grains. A third leaf was examined 5 days after the drops had been given, and the aggregated masses appeared to be breaking up into small highly transparent spheres. In two, however, of the short central tentacles of this leaf the cells at their bases contained no aggregated matter and plenty of chlorophyll-grains. It is probable that if these tentacles had been examined two or three days earlier, an opposite state of things would have prevailed. In a third central tentacle from this same leaf there was still much aggregated matter in the basal cells; and here a few irregularly shaped chlorophyll-grains could be seen. In other tentacles from this same leaf, and from two other leaves which had been similarly treated, some of the aggregated masses had become granular, discoloured, and opaque; and this indicates that the solution had either been too strong, or that too large a quantity had been given. Drops of a strong filtered solution of raw meat were now placed on 7 reddish leaves, the tentacles of which all became much inflected and their glands blackened. After 22½ hours they were syringed with water, and one leaf was cut off for examination. The contents of five

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short central tentacles from this leaf were aggregated down to their bases, and not a grain of chlorophyll could be seen. Some of the aggregated masses were almost white with a faint tinge of green, and were moving quickly. In the long exterior tentacles which had not at first been touched by the infusion (that is, not until they had become inflected), the aggregation had not as yet travelled down to the basal cells; and here the grains of chlorophyll were quite distinct. The infusion was too strong; for after five days one out of the six remaining leaves was dead; two others were much injured, with the outer tentacles killed, those on the disk, though immersed for a longer time, being still alive; the fourth leaf was considerably injured; the fifth and sixth looked fresh and vigorous, with their glands, now of a red colour, secreting freely. Five of the short central tentacles from one of these latter leaves were now (i.e. after the five days) examined: in three of them only a trace of aggregation was left, and plenty of chlorophyll-grains could be seen; in a fourth tentacle there were still some aggregated masses and a few chlorophyll-grains; in a fifth there were many aggregated masses and some fine granular matter, and here no chlorophyll-grains were distinguishable. There can |274| hardly be a doubt that in four out of these five tentacles the chlorophyllgrains had been reformed. On one of the much-injured leaves, in which the glands of the central tentacles were still opaque, the cells in their footstalks contained some aggregated and some brownish granular matter; and here minute globules were arranged along the walls of the cells in the places where chlorophyll-grains ought to have stood; but whether these were remnants which had never wholly disappeared or new grains reforming could not be ascertained. Drops of a weaker infusion of raw meat were next placed on seven reddish leaves, which were all greatly acted on; but the infusion was still rather too strong. In from 24 to 25 hours afterwards all the leaves were well syringed; and small pieces having been cut off two of them, several of the short central tentacles were examined. In one of these leaves a very few chlorophyll-grains could be seen in some few cells in one of the tentacles which had not undergone so much aggregation as the others. In the piece from the second leaf not a single chlorophyll-grain could be distinguished in any of the short central tentacles. The sections were then immersed in alcohol, and in a few minutes all the aggregated masses were broken up into very fine granular matter; but no chlorophyll-grains could be seen, except in the one tentacle above mentioned. In three days after the drops had been first given, four of the leaves (including one of those from which a small piece had been cut off) looked vigorous, and were fully or almost fully expanded. The fifth leaf, from which a piece had likewise been cut off, appeared somewhat injured. The sixth had its tentacles still inflected and seemed much injured, and was apparently almost dead. Four of the central tentacles on the vigorous leaf, from which a piece had been cut off, after 24 hours, were now (i.e. on the third day after the drop had been given) examined. In most of the basal cells of three of these tentacles only a trace of aggregation was left, and many chlorophyll-grains could be seen in them; but these were not so regular in shape or so regularly placed as are the normal grains; so that I presume they were in the act of reforming. Two basal cells in one of these tentacles still contained large quickly moving aggregated masses, and not a grain of chlorophyll could be distinguished in them. When this section was

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irrigated with the solution of iodine, the aggregated masses in the two just-mentioned cells instantly broke up |275| into brownish granular matter, and the irregular and, as I supposed, just reformed chlorophyll-grains in the adjoining cells ran together and became confluent, forming narrow rims along the walls. After intervals of 4, 6, and 8 days from the time when the drops were given, 15 central tentacles on three of the leaves were examined; and in all of these tentacles, excepting one in which there was still much aggregated matter, chlorophyll-grains could be seen. After 11 days one of the leaves, from which a small piece had been cut off after an interval of 24 hours, and in which most of the central tentacles then included no chlorophyll-grains, was now reexamined. The central tentacles appeared perfectly healthy and were secreting: in 8 out of 10 of them, the cells included chlorophyll-grains having the usual appearance; in the other two tentacles there was still much aggregated matter and no ordinary chlorophyllgrains, but some few irregularly shaped chlorophyll-grains. With respect to the second leaf, from which a small piece had been cut off, and in which the central tentacles did not then (i.e. after 24 hours) contain a single chlorophyll-grain, only a very few of the central tentacles now (i.e. after 11 days) appeared healthy; but in two of them, which appeared quite uninjured, there were innumerable perfect chlorophyll-grains in all the cells from the glands down to the base. Considering the whole of the evidence here given, there can hardly be a doubt that with the leaves of Drosera as soon as the aggregated masses break up, and even before they are wholly redissolved, grains of chlorophyll are reformed. Drosophyllum lusitanicum.3—The footstalks of the tentacles are bright green, from the large number of chlorophyll-grains which they contain. Two leaves were immersed in a solution of carbonate of ammonia (4 to 1000) for 23 and 24 hours, and the cells of the footstalks now contained innumerable spheres, some much smaller and some much larger than the grains of chlorophyll, and other oddly shaped masses, more or less confluent, of translucent bright-yellow matter, which, when irrigated with alcohol, instantly broke up into fine granular matter. I looked in vain in several of these tentacles for grains of chlorophyll. Another leaf was immersed for only 16½ hours in a weaker solution of 2 to 1000; but this sufficed to produce an abundance of yellow translucent bodies, which were seen to change their forms greatly, |276| though slowly. In many, but not in all, of the cells of this leaf the grains of chlorophyll were still quite distinct. The several leaves were left both in the stronger and weaker solutions for 48 hours; and this caused the yellow spheres and masses to disintegrate into brownish granular matter. In this respect the aggregated masses in Drosophyllum differ from those in Drosera and Dionæa. Leaves were also left for 24 and 48 hours in an infusion of raw meat; but no yellow aggregated masses were thus produced, and the grains of chlorophyll remained perfectly distinct. This singular difference in the action of the infusion of raw meat on the tentacles, as compared with those of Drosera, may perhaps be accounted for by their serving in Drosophyllum almost exclusively for the secretion of the viscid fluid by which insects are captured—the power of digestion and of absorption being chiefly confined, as I have explained in my ‘Insectivorous Plants’ (pp. 332–342), to the minute sessile glands on the disks of the leaves. As in the three

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foregoing genera the grains of chlorophyll tend to aggregate into moving masses under the long-continued influence of a weak solution of carbonate of ammonia, I thought that the grains would probably be similarly acted on in all insectivorous plants; but this did not prove to be the case. The immersion of leaves of the common Pinguicula in a solution of the ammonia and in an infusion of raw meat did not cause any aggregation of the chlorophyllgrains, though numerous transparent spheres were formed within the glandular hairs. Again, the immersion in carbonate of ammonia of pieces of young and old pitchers of a Nepenthes (garden hybrid variety) caused the appearance of innumerable more or less confluent spheres of various sizes in the glands on the inner surface of the pitcher and in the exterior epidermal cells. These were formed of translucent matter, either almost colourless or of a brown, orange, purple, or greenish tint; but the grains of chlorophyll were not acted on. Sarracenia purpurea.4—The pitchers of this plant are evidently adapted for catching and drowning insects; but whether they can digest them, or may have the power of absorbing matter from their decaying remains, is doubtful.* Many observations |277| were made; but one case will suffice. A piece of a pitcher was left for 24 hours in a solution of 4 parts of the carbonate of ammonia to 1000 of water, and for 24 additional hours in a solution of 7 to 1000. In the cells of the parenchyma, especially in those close to the vascular bundles, there were many spheres and aggregated masses of bright orange transparent matter. Spheres of the same and of various other tints were present in the epidermal cells, more especially in those on the inner surface of the pitcher; and some of these spheres were of exactly the same pale greenish colour as the swollen chlorophyll-grains which were still present in some places, being often collected together into rounded masses. In many of the epidermal cells which contained spheres no chlorophyll-grains could be seen, though they were abundantly present in the epidermis of fresh leaves; and it is this fact which chiefly leads me to believe that the chlorophyll-grains sometimes become so completely fused together as to form spheres, being often blended with the aggregated and coloured cell-sap. When a solution of iodine was added to these sections, the pale-coloured spheres and irregularly shaped aggregated masses became bright orange, and they were sometimes sprinkled over with blue particles of starch. The iodine did not cause their immediate disintegration and disappearance, nor did alcohol or acetic acid. In this respect they differ from the recently aggregated masses in Drosera; though in this latter plant the older and more solid aggregated masses are not acted on by these reagents. Many of the cells contained green granular matter, formed either by the chlorophyll-grains having been mechanically smashed or by their disintegration; and acetic acid sometimes caused this granular matter to change instantly into the same orange tint as that of the aggregated masses. The orange spheres and variously shaped masses were seen in many sections of pitchers which had been exposed for different lengths of time to solutions of the carbonate of different

*

See an interesting account of the inner epidermal cells by A. Batalin, “Ueber die Function der Epidermis in den Schlãuchen von Sarracenia &c.” 1880. Reprinted from ‘Acta Horti Petropolitani,’ t. vii. (1880). [Alexander Feodorowicz Batalin (1847–96), Russian botanist and plant physiologist. Batalin 1880.]

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strengths; and in many of them swollen grains of chlorophyll had become more or less confluent. The original nature of the latter could be recognized by the sinuous outlines and greenish tint. They were not seen to change their shapes spontaneously; but this could not have been expected in sections. Portions of a pitcher left in distilled water for nearly three days did not exhibit a single orange sphere or aggregated mass; but there were some colourless oil-globules which were dissolved by alcohol; |278| and the chlorophyll-grains, though generally much swollen, were still distinct. It may therefore be concluded that in Sarracenia the chlorophyll-grains often undergo aggregation under the influence of carbonate of ammonia, but that they are less easily acted on than those of Dionæa and Drosera. Leaves with Glandular Hairs and Other Leaves.—I had formerly observed, as described in my ‘Insectivorous Plants,’ that the glandular hairs of some plants absorb carbonate of ammonia and animal matter, and that aggregation is thus caused in them. Consequently such leaves and others without hairs were immersed in solutions of carbonate of ammonia (4 and 7 to 1000) generally for 24 hours. No marked effect was produced on the chlorophyll-grains, excepting their occasional displacement, in the following cases (plants were selected almost by hazard, but which belong to different families):—first, of leaves not bearing many or any glandular hairs, namely those of Brassica, Fumaria, Fuchsia, Robinia, Oxalis, Tropæolum, Euphorbia, Stapelia, Beta, Allium, Lemna, a fern (Nephrodium), a Marchantia, and a moss. Nor were the grains acted on in two species of Saxifraga (except on one occasion, when they formed masses shaped like a horseshoe, presently to be described), nor in Primula sinensis—although the leaves of these three species are clothed with glandular hairs, which absorb carbonate of ammonia and undergo aggregation. Young leaves of Dipsacus sylvestris were immersed for 24 hours in a solution of 7 to 1000, and large yellowish highly refracting spheres were formed in the upper epidermic cells which do not include any chlorophyllgrains, and the grains were not at all aggregated in other parts of the leaf. When the sections were irrigated with acetic acid or with alcohol, the spheres in the epidermal cells disappeared quickly, in nearly the same manner as occurs with recently aggregated masses in the cells of Drosera. Leaves of Cyclamen persicum, which bear hardly any glandular hairs, were left in a solution of 7 to 1000 for 43 hours, and this caused the chlorophyll-grains to collect into heaps; in some parts the grains retained their outlines distinct; but in other parts they formed perfectly homogeneous bright-green masses of the shape of a horseshoe. These were cleared by alcohol; and it was evident that the grains had become completely fused together. It is remarkable that many of the central cells near the vascular bundles contained spherical or oddly shaped confluent |279| globules of pale-blue transparent matter. In the preceding paper an analogous result from the action of carbonate of ammonia is described in the underground stems and rhizomes of Mercurialis perennis. The leaves were left for 24 additional hours in the solution, and now the horseshoe masses disappeared, being converted into pulpy matter. The immersion of the leaves of this Cyclamen in water for 47 hours caused the chlorophyll-grains to accumulate into heaps, as is know to follow from any injury there was hardly a trace of their confluence, and none of the pale-blue globules were present. Similar horseshoe masses were seen, but only on one occasion, in the leaves of Nicotiana

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tabacum after their immersion in the solution; and so it was with the stems of Euphorbia Peplus. Portions cut from a leaf of Mirabilis Jalapa were left for 16½ hours in solutions of 4 and of 7 to 1000, and the chlorophyll-grains in many of the cells became completely confluent, forming horseshoe masses or rings; and they were sufficiently solid to project when the cells were torn open. When these horseshoe masses and rings were irrigated with acetic acid, they became so transparent that even their outlines could hardly be distinguished. If in these plants, and more especially in Cyclamen and Mirabilis, the confluent chlorophyll-grains forming the horseshoe masses are still alive (and this is rendered probable by their bright-green colour, and in the former plant by their breaking up when left for an additional day in the solution, and in the latter plant by the action of acetic acid on them), we have in these cases a first step in the process which in some plants leads to the formation of spontaneously moving masses lying free in the cell-sap. Pelargonium zonale.5—The effects produced by the immersion of the leaves of this plant for 24 or 48 hours in solutions of 4 or 7 parts of carbonate of ammonia to 1000 of water are not a little perplexing. The leaves are clothed with glandular hairs, which absorb the ammonia and undergo aggregation. Moreover, numerous almost colourless, shining, translucent spheres generally, but not invariably, appear in most of the epidermal cells in which there are no grains of chlorophyll, and in the palisade-cells, in which they abound, and likewise in the parenchyma. The smaller spheres blend together, and thus form large ones. A solution of only 2 to 1000 sometimes sufficed to produce the spheres. Usually the spheres are not acted on by alcohol, but occasionally they were dissolved by it. If after immersion in |280| alcohol they are subjected to the iodine solution, they soon almost disappear; but this, again, does not invariably occur. Acetic acid always caused their rapid disappearance, and without any apparent effervescence, a slight granular residue being sometimes left; and this occurred with leaves which had been kept so long in the solution that they were dead. The acid dissolved, of course with effervescence, the crystalline balls of carbonate of lime which occupy many of the palisade-cells. When sulphuric ether was added, the smaller spheres of transparent matter disappeared in the course of a few minutes, while the larger ones became brownish and granular in their centres; but this granular matter disappeared after a time, empty transparent bag-like membranes being left. Traces of similar membranous envelopes could sometimes be detected after the administration of acetic acid. Caustic potash did not act quickly on the spheres, but sometimes caused them to swell up. I do not know what ought to be inferred from the action of these several reagents with respect to the nature of the spheres and aggregated masses in which I never saw any movement. On two or three occasions the palisade-cells of leaves which had been immersed in the solutions, instead of containing large transparent spheres, were gorged with innumerable, often irregularly-shaped, more or less confluent globules, many of them being much smaller than the chlorophyll-grains. This occurred with a leaf which had been immersed for only 18½ hours in a solution of 4 to 1000. After sections of this leaf had been cleared with alcohol, it was irrigated with the solution of iodine, and the globules rapidly ran together or became confluent, forming irregular amorphous masses.

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It was difficult to ascertain whether the chlorophyll-grains ever or often became blended with other matter, and thus aided in the formation of the transparent spheres. The difficulty was partly due to the grains being easily acted on by water. Thus, in some sections made and placed in water, and then cleared in alcohol, no grains could be distinguished; while they were distinct in sections of the same leaf which had not been wetted before being placed in alcohol. Many grains were also found in a disintegrated condition in uninjured leaves which had been kept for 47 hours in water. It may be here added that not a single sphere could be seen in these leaves; nor were they present in leaves slightly injured by being kept for 24 hours in a very weak |281| solution of osmic acid. Nor, again, in a leaf which had been immersed in an infusion of raw meat for 24 and for 50 hours; and in this leaf the chlorophyll-grains were still visible in many places, but were sometimes heaped together. Notwithstanding the difficulty of ascertaining the effects of carbonate of ammonia on the chlorophyll-grains, chiefly owing to the action of water on them, I am led to believe, from the gradations which could be followed, and from the absence of chlorophyll-grains in the cells in which one or two large spheres were present, that in the case of the palisade- and parenchyma-cells matter produced by the disintegration of the grains first aggregates, together with other matter derived from the cell-sap, into minute globules, and that these aggregate into the larger spheres. I will give a single instance:—A leaf was immersed for 22½ hours in a solution of the carbonate of 4 to 1000, and sections, after being cleared in alcohol, exhibited in many places distinct chlorophyll-grains, and in other places only very fine granular matter, and in a very few cells minute transparent globules. The leaf was left for 24 additional hours in the solution; and now sections cleared in alcohol exhibited numerous minute shining translucent globules, many of which were smaller than the few remaining chlorophyll-grains. There were also other much larger transparent spheres, more or less confluent, which, when irrigated with acetic acid, instantly disappeared. A leaf was immersed in a solution of 4 parts of phosphate of ammonia to 1000 of water, and after 23 hours there was no trace of aggregation. It was left for 24½ additional hours in the solution; and now sections cleared in alcohol exhibited not only minute shining colourless globules, smaller than the few remaining chlorophyll-grains, but plenty of large spheres, more or less aggregated together; and in the cells containing such spheres no chlorophyllgrains could be seen. The spheres, both large and small, disappeared instantly when acetic acid was added, as in the case of those produced by the carbonate. It appears, therefore, that these two salts act in the same manner, but that the phosphate acts more slowly than the carbonate, as is likewise the case with Drosera. A leaf immersed for 45 hours in a solution of 2 parts of nitrate of ammonia to 1000 of water was a good deal infiltrated and darkened in colour; but no spheres were formed; some of the chlorophyll-grains had, however, become confluent while still adhering to the walls of the cells. |282| Spirogyra (crassa ?).—When filaments of this alga were placed in a solution of carbonate of ammonia (4 to 1000), the cell-sap became in a few minutes cloudy from the formation of innumerable granules, and the green spiral chlorophyll-band soon began to contract. A filament was irrigated under a cover-glass at 11.10 A.M. (Oct. 4) with the solution; and by 11.25 the cell-sap had everywhere become granular: in two of the cells the pointed ends of

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the chlorophyll-band and the irregular lateral projections were retracted, so that these bands now appeared much smoother and blunter than before. In two neighbouring cells the bands had become converted into circular masses surrounding the nuclei. At 12.50 two cells were selected for further observation: in one of them the original spiral band now formed a layer of nearly uniform thickness, except in three of the corners where there were rounded lumps, which adhered closely to the two transverse and to one of the longitudinal walls of the cell. By 4 P.M. the layer on the longitudinal wall had become in the middle so thin that it consisted of a mere thread, which at 4.15 broke and disappeared; the upper end (with reference to the observer) of the layer then rapidly contracted into a pear-shaped mass. The layer at the lower end of the cell had by this time assumed a dumb-bell shape, which, however, soon afterwards became cylindrical. At 7.10 P.M. the appearance of the cell was utterly different; for there were now at the upper end two illdefined masses, and at the lower end two somewhat irregular balls of green matter connected together by a thin band. At 8 A.M. on the following morning there was a large oval mass lying obliquely across the upper end of the cell, with its two extremities connected by bands with two spheres in the lower corners. The changes in the other cell, which was observed at the same time, were almost equally great. The spiral band was first converted into two layers lining the two transverse walls, and these were connected together by a sinuous longitudinal band. At 4 P.M. there was in one of the corners a large pear-shaped mass, which contracted while it was watched into an oval mass, and at the opposite corner a small dark-green sphere. By 7.10 P.M. there were two spherical masses and an oval one, which latter by the next morning formed a much elongated dark band; and instead of two there was now only a single separate sphere. |283| At this same time two adjoining cells included four and five oval or spherical chlorophyll-balls; but one cell still retained a spiral band. Alcohol and acetic acid produced only the same clarifying effect on these masses as in the case of ordinary chlorophyll-grains. Filaments of this alga were left for 26 hours in a solution of only 1 part of the carbonate to 1000 of water; but this sufficed to cause some granular deposition in the cell-sap, and many of the cells included, instead of the spiral band, spherical or oval or pear-shaped masses (and in one instance a half-moon-shaped mass) connected together by the finest threads of green matter, one of which was seen to break, and the pear-shaped mass quickly became almost spherical. The changes of form and the movements of the chlorophyll-band in the foregoing several cases, under the influence of the ammonia solution, closely resemble in most respects those which may be seen within the tentacles of Drosera. The above weak solution seemed to be favourable to the health of the plants; for after six days’ immersion they looked greener and more vigorous than other plants of the same lot which had been kept in plain water. The cell-sap still contained brownish granular matter, and many of the cells oval or spherical masses. The brownish granular matter is always precipitated quickly; and when three young cells, which were as transparent as glass, were irrigated with a solution of 7 to 1000, the precipitation seemed to be instantaneous. After a time the granules are either deposited on the protoplasm lining the walls of the cells, or they collect into one or two spherical masses

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in the middle of the cell. These spheres apparently consist of a delicate membrane lined with granules and enclosing cell-sap. They distinctly lay within the spiral band of chlorophyll. Their appearance reminded me of the bag-like masses sometimes produced within the cells of dark-red leaves of Drosera when acted on by ammonia. In one instance the granules became collected into a spiral band. They were not acted on by alcohol, sulphuric ether, acetic acid, or a solution of iodine. Alcohol caused the protoplasm lining the walls to contract, by which means the granular matter and chlorophyll-bodies were all carried towards the centre of the cell. Three other kinds of Conferva were immersed in a solution of the carbonate, and were casually observed. In the first, in which |284| the cell-walls were dotted over with chlorophyll-grains, there was at first some slight degree of aggregation, and then the grains all became disintegrated. In the second species, the filaments of which were extremely thin, the solution produced no effect. In a third the chlorophyll-bodies became aggregated into spheres. If the species in this family are difficult to distinguish, systematists might probably derive aid by observing the different actions of a solution of carbonate of ammonia on them. Conclusion.—From the facts given in this paper we see that certain salts of ammonia, more especially the carbonate, quickly cause the cell-sap in various plants belonging to widely different groups to deposit granules apparently of the nature of protein. These sometimes become aggregated into rounded masses. The same salts and, in the case of Drosera, an infusion of raw meat tend to act on the chlorophyll-bodies, causing them in some few species to become completely fused together, either in union with the aggregated cell-sap or separately from it. Aggregation seems to be a vital process, as it does not occur in recently killed cells; and any thing which kills a cell causes the already aggregated masses instantly to disintegrate. These masses, moreover, display in some cases incessant movements. The process of aggregation is not rarely carried so far that the masses lose the power of movement; nor do they then readily disintegrate when subjected to any deadly influence. From these facts, from other considerations, and more especially from the action of carbonate of ammonia on the chlorophyll-bodies, I am led to believe that the aggregated masses include living protoplasm, to which their power of movement may be attributed. The most remarkable point in the whole phenomenon is, that with the Droseraceæ the most diverse stimuli (even a stimulus transmitted from a distant part of the leaf) induces the process of aggregation. The redissolution in the course of a few days of the solid aggregated masses and, especially, the regeneration of the chlorophyll-grains are likewise remarkable phenomena.

1

2 3 4 5

Insectivorous plants chapter 3. An abstract of this article, together with Darwin 1882, F1800 (p. 470), was published by Francis Darwin: The action of ammonia on the roots of certain plants and on chlorophyll bodies. Nature 25 (23 March 1882): 489–90. Friedrich Wilhelm Beneke (1824–82), German physician and physiologist. Beneke 1862. Portuguese Sundew or Dewy pine. Purple pitcher plant or Side-saddle flower. Garden geranium.

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1882. The action of carbonate of ammonia on the roots of certain plants. By Charles Darwin, LL.D., F.R.S. [Read by Francis Darwin 16 March] Journal of the Linnean Society of London. Botany 19: 239–61. F1800 Many years ago I observed the fact that when the roots of Euphorbia Peplus1 were placed in a solution of carbonate of ammonia a cloud of fine granules was deposited in less than a minute, and was seen travelling from the tip up the root from cell to cell.* The subject seemed to me worthy of further investigation. Plants of the same Euphorbia were therefore dug up together with a ball of earth, and having been left for a short time in water, the roots were washed clean. Some of the finer transparent rootlets were then examined, and sections were made of the thicker roots, generally by my son Francis, who has aided me in many ways. All the cells were found to be colourless and destitute of any solid matter, the laticiferous ducts being here excluded from consideration. These roots, after being left for a few minutes or for several hours in solutions of different strengths, viz. from 1 to 7 parts of the carbonate to 1000 of water, presented a wonderfully changed appearance. A solution of only 1 part to 10,000 of water sufficed in the course of 24 hours to produce the same result. In well-developed cases the longitudinal rows of cells close to the tip of the root, with the exception of those forming the extreme apex, were filled with brown granular matter, and were thus rendered opaque. Long-continued immersion in water produced no such effect. The granular masses were square in outline, like the cells in which they were contained; but they often became rounded after a day or two; and this was apparently due to the contraction of the protoplasmic utricle. Above the dark-brown cells, which form a transverse zone close to the tip, and which apparently corresponds with the zone of quickest growth, the roots, as seen under a high power, are longitudinally striped with darker and lighter brown. The darker tint is due to the presence of innumerable rounded granules of brownish matter; and the cells containing them are arranged in longitudinal rows, while other longitudinal rows are destitute of granules. In a few instances the rows differed slightly in tint, and yet no |240| granules could be seen in the darker cells; and I suppose that this was owing to their being too minute to be visible. Occasionally, in the upper parts of the roots, the granules became confluent, and formed one or two small rounded masses of hyaline brown matter. The striped appearance sometimes extended from the tips of the finest rootlets close up to the stem of the plant. On a casual inspection it would be said that the longitudinal rows of brownish and of almost colourless exterior cells regularly alternated with one another; but on closer examination, two or three adjoining rows of cells were often seen to contain granules, and in other places two or three ordinary rows contained only colourless fluid. In one instance many adjoining longitudinal rows contained granules; but the tendency to alternation was even here well shown, as the alternate rows differed in tint from including a greater or less number of granules. High up the roots the alternations often quite failed, as all the exterior cells *

‘Insectivorous Plants,’ 1875, p. 64. The subject was at that time, 22 years ago, only casually investigated; and I believe that I erred greatly about Lemna, unless, indeed, some different species was then observed, or that the season of the year makes a great difference in the behaviour of the roots, which is not probable.

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contained granules. If a longitudinal row of cells with granules is traced up a rootlet, it is seen to be soon interrupted by one or more colourless cells; but I have traced as many as 18 cells in a row all containing granules. So, again, a longitudinal row of colourless cells changes after a time into one with granular matter. As a root thickens upwards, some of the longitudinal rows of cells divide into two rows; and a row containing granules may divide into two such rows, or into one with and another without granules; and so it is with dividing rows of colourless cells. I could not perceive the least difference in shape or size, or in any other character, between the cells of the same rank which contained and those which were destitute of granules. Near the tip of the root it is the exterior cells which become charged, after immersion in the solution, with brown granular matter; and this often holds good with the cells of the root-cap. Higher up the root, the layer of cells formed by the alternating longitudinal rows with and without granules is sometimes bounded externally by a layer of empty cells, which, I suppose, had by some means been emptied of their contents, and were ready to be exfoliated. Besides the exterior cells with and without granules, many separate cells in the parenchyma at different depths from the surface, and all or several of the elongated endoderm-cells surrounding the central vascular bundle, are more or less filled with granular matter, none of which cells contained any solid matter before the roots were immersed in the solution. |241| I should have felt little surprise at the effect produced by the solution if all the cells of the same nature (for instance, if all the exterior cells or all the parenchyma-cells) had been equally affected. The strong tendency to alternation in the exterior cells is more especially remarkable. There is also another remarkable fact with respect to these latter cells, namely, that those containing the granules do not give rise to root-hairs, as these arise exclusively from the colourless and apparently empty cells. In longitudinal sections of one root, 62 hairs were traced down to such colourless cells; and I was not able to find a single one arising from a cell which contained granules. But I shall have hereafter to return to this subject. With respect to the rate at which the granular matter is deposited, if a rootlet is placed under a cover-glass and irrigated with a few drops of the solution, some deposition occurs before the slide can be transferred to the microscope and the focus adjusted. A thin rootlet was therefore arranged for observation, and a drop of the solution (7 to 1000) placed on the edge of the cover-glass, and in 20 seconds the cells near the tip became slightly clouded. Another thin rootlet was placed with the tip projecting beyond the cover-glass, and the focus was adjusted to a point at a distance of .07 inch from the tip, on which a drop of the solution was then placed, and the cells at the above distance became cloudy in 2 m. 30 sec. Various other solutions, beside that of carbonate of ammonia, caused the deposition of granules in the same cells as in the foregoing cases. This occurred conspicuously with a solution of 4 parts of phosphate of ammonia to 1000 water; but the action was not so rapid as with the carbonate. The same remarks are applicable to nitrate of ammonia. A solution of one part of fuchsine, which contains nitrogen, to 50,000 of water distinctly acted. A solution of 2.5 parts of pure carbonate of soda to 1000 water caused, after 24 hours, the cells close to the tip to become very brown from being charged with fine granular matter; and higher up

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the rootlets, longitudinal rows of cells, either containing coarse granules or pale-brown fluid without any distinguishable granules, alternated with rows of colourless cells. Lastly, roots immersed for only one hour in a watch-glass of water, to which two drops of a 1-per-cent. solution of osmic acid had been added, presented an extraordinary appearance; for the exterior cells in alternate rows, some parenchyma, and most of the endoderm-cells contained much almost black granular matter. |242| The granules precipitated through the action of carbonate of ammonia are never afterwards, as far as I could judge, redissolved. Roots still attached to living plants were immersed in solutions of 1 part of the carbonate to 500, to 2000, and to 4000 parts of water, and granular matter was deposited in the cells in the usual manner. The roots were then left in damp peat or in water, with the stems and leaves exposed to the air and light, for various periods between 2 and 15 days. The roots were then reexamined at different times, and granules were found in almost every instance in the cells. But it should be noticed that though the plants themselves looked healthy, the finer roots were flaccid, and sometimes showed evident signs of decay; so that it was manifest that they had been much injured by the treatment to which they had been subjected, probably by their immersion in the solution. With respect to the nature of the granules, I can say but little. They were not dissolved by long-continued immersion in alcohol or in acetic acid, or by irrigation with sulphuric ether. They were not dissolved by a 10—per-cent. solution of common salt, which was tried at the suggestion of Mr. Vines,2 who has found that this solution dissolves aleurone-grains either partially or completely. When sections or rootlets containing freshly deposited granules were left for a day or two in glycerine and water, these were sometimes broken up, so as to be no longer visible, and the cell-sap in this case acquired a brownish tint. When sections or thin rootlets were heated for a short time in a moderately strong solution of caustic potash, and afterwards left in it for a day or two, the granules were dissolved; whereas the hyaline globules in the laticiferous ducts were not dissolved. From these several facts I suppose that the granules are of the nature of protein. After roots had been left for 2 or 3 minutes in water heated to a temperature of 210°–212° F., and were then placed in a strong solution of the carbonate of ammonia, no granular matter was deposited; and this seems to indicate that the action is a vital one. On the other hand, granules were often deposited in the cells, even the loose cells, of the root-cap, and it is very doubtful whether these could be alive. I may add that these root-cap cells were coloured, by a weak solution of fuchsine, of a brighter pink than those in other parts of the rootlets. Other Euphorbiaceous Plants.3—The exterior cells of the roots of Euphorbia amygdaloides were much less acted on (Nov. 16) by |243| a solution of carbonate of ammonia than those of E. Peplus. Here and there two and three cells in a row contained brownish granules, and these abounded in the elongated endoderm-cells. Nearly the same remarks are applicable to E. myrsinites, though in most specimens the cells with granules were still rarer. The roots of two fleshy species, E. rhipsaloides and ornithopus, did not appear to be at all affected by the solution.

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Turning now to other Euphorbiaceous genera, the roots of Poinsettia pulcherrima, Manihot Glaziovi, Croton oblongifolium, and Hevea Spruciana were not affected. Nor were those of Mercurialis perennis, as far as the exterior cells are concerned; but here and there a single cell in the parenchyma became blue; but these cells were not carefully examined.* Judging from the cases presently to be given, they probably contained granules which had been precipitated by the ammonia solution. On the other hand, the roots of Phyllanthus compressus were conspicuously acted on by an immersion of 21 hours in a solution of 4 parts of the carbonate to 1000 of water, though in a somewhat different manner from those of Euphorbia Peplus. In parts the exterior cells in many adjoining longitudinal rows contained brownish granules; while in other parts at no great distance many adjoining rows were colourless and empty—that is, contained no solid matter. For instance, in one place 13 longitudinal rows with granules ran alongside one another, then came a single row of empty cells, and then at least 9 rows with granules. In another place there were 13 adjoining rows of cells all empty. When one of these rows was followed up or down the root for some distance, it changed its character, either becoming or ceasing |244| to be granular, and then resuming its former character. Close to the tips of the roots all the longitudinal rows of cells contained brownish matter; but this matter in several instances consisted of small dark-brown spheres, due apparently to the aggregation of granules. The endoderm-cells round the vascular bundle contained either similar spheres or granular matter. As many adjoining rows of cells on the surface of the roots of this plant had the same character, an excellent opportunity was afforded for observing the relation of the root-hairs to the cells; and in several dissected roots it was manifest that, as a general rule, the hairs rose exclusively from the colourless empty cells; whereas none arose from those containing granules. Twice, however, partial exceptions to this rule were observed: in one case the exterior walls of two adjoining cells, and in another case those of four adjoining cells, projected, so that they formed short blunt papillæ which included granules; and these papillæ exactly resembled nascent root-hairs. It is not, however, certain that they would ever have become fully developed. All the exterior cells close to the tip of the root in this case and in many others contained matter which was acted on by carbonate of ammonia; and I was led by various appearances to suppose at one time that this matter remained in all the higher cells until it was consumed in some of them by the formation of the root-hairs. These consequently would arise exclusively from cells in which no granules would be deposited when they were acted on by the solution. In opposition to this supposition is the fact, first, that root-hairs could be seen beginning to be *

The rhizomes and buried parts of the stems of this plant are white; but after immersion for a day in the ammonia solution they became in parts either pale or rich blue. This change of colour occasionally occurred in parts exposed to the air which had not been subjected to the solution. As a similar change occurs in certain cells in the roots of various plants after their immersion in the solution, I asked Mr. Sorby to be so kind as to examine the rhizomes and underground stems of the Mercurialis. He informs me that he does not understand the change of colour; but he was unable to spare time for a full examination. He found that when the rhizomes and stems were boiled in alcohol, they yielded matter which was soluble in water, and which appeared to pass so rapidly into a brown substance with curious shades of green, that the real change was hidden. On the whole, the appearances differed a good deal from those observed by him in the case of blue flowers. [Henry Clifton Sorby (1826–1908), geologist who pioneered microscopic petrology. Sorby was part of the deputation of the Yorkshire Naturalists’ Union which presented a memorial to CD in 1880. See Darwin 1880, F1969 (p. 434).]

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developed from empty cells; and, secondly, that very many cells which were empty apparently had never produced root-hairs. Nor does this notion throw the least light on single cells in the parenchyma and on many cells, though not all, in the endoderm containing granular matter. With another Euphorbiaceous plant, Cœlebogyne ilicifolia, the immersion for 20 hours of its roots, or of thin sections of the roots, in a solution of 4 parts of carbonate of ammonia to 1000 parts of water produced a singular effect; for many separate cells in the parenchyma and those in the endoderm surrounding the vascular bundle assumed a pale or dark blue, and sometimes a greenish colour. As far as I could judge, both the granules within these cells and the cell-sap became thus coloured. Irrigation with sulphuric ether did not affect the colour, though the many oil-globules in the cells were dissolved. |245| The foregoing observations on the Euphorbiaceæ led me to experiment on the roots of some other plants belonging to various families. At one time I erroneously imagined that there was some relation between the deposition of granules in certain cells and the presence of laticiferous ducts, and consequently an undue number of plants with milky juice were selected for observation. A solution of carbonate of ammonia produced no obvious effect on the roots of a small majority of the plants which were tried; but on several a slight, and on others a marked, effect was produced. I should state that when the exterior appearance of a root did not indicate any action, sections were rarely made; so that the interior cells were not examined. No obvious effect was produced with the following plants:—Argemone grandiflora, Brassica oleracea, Vicia sativa, Trifolium repens, Vinca rosea, Hoya campanulata, Stapelia hamata, Schubertia graveolens, Carica Papaya, Opuntia boliviensis, Cucurbita ovifera, a Begonia, Beta vulgaris, Taxus baccata, Cycas pectinata, Phalaris canariensis, a common pasture-grass, Lemna, and two species of Allium. It may perhaps be worth notice that the radicles, but not the hypocotyls, of seedlings of Beta vulgaris were completely killed by an immersion for 20 hours in solutions of either 4 or of only 2 parts of the carbonate to 1000 of water; and this occurred with no other plant which was tried. With the following plants the solution produced some slight effect. The roots of a fern, Nephrodium molle, were immersed for 20 hours in a solution of 4 to 1000; and this caused the deposition of some brown granular matter in the cells near their tips; and more or less confluent globules could be seen in the underlying parenchyma-cells. So it was with an unnamed greenhouse species of fern; and in this case the almost loose cells of the root-cap contained brown granules. The roots of a Ranunculus (R. acris ?) similarly treated exhibited near their tips brown granular matter. The tips also of the roots of Dipsacus sylvestris became, under similar treatment, almost black; and higher up the roots, here and there a single parenchyma-cell was coloured pale blue. This occurred in one instance when a rootlet was looked at 35 minutes after irrigation with the solution. Several roots of Apium graveolens were left for 20 and 24 hours in solutions of 4 and 7 to 1000; and in some cases brownish granules, more or less aggregated together, were deposited in some of the exterior cells, and a few of the deeper cells in the parenchyma |246| were coloured blue. The tips of the roots of Pastinaca sativa turned dark brown by a similar immersion; but this was due to the formation of orange-brown balls of matter near the vascular bundle; higher up the roots there were no granules in the exterior cells. The tips of the roots of Lamium purpureum, after

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an immersion of 18 hours in a solution of 4 to 1000, were rendered brown, and the cells contained innumerable pale-coloured hyaline globules. The older roots of Leontodon Taraxacum and of a Sonchus had their tips turned brown by the solution. With Lactuca sativa the tips were rendered opaque; but much granular matter was not deposited except in that of one rather thick leading root, and here short longitudinal rows of cells containing dark-brown granular matter alternated with rows of colourless cells; the almost loose cells of the root-cap likewise contained brown granules. In the several following cases a much more strongly marked effect was produced by the solution. Urtica.—This plant, the common nettle, shall be first considered, as it is distantly allied to the Euphorbiaceæ, though the roots are not so much affected as in succeeding cases. Several roots were left for 27 hours in a solution of the carbonate (4 to 1000). In one of them the exterior cells were plainly tinted of a brown colour in many longitudinal rows, but they contained no visible granules; and these rows regularly alternated with others formed of colourless cells. In another part of this same root all the exterior cells were coloured dark brown, and contained visible granules, which were generally collected into heaps at one end of the cell, or were fused together in some instances into small brown spheres. In a second, rather thick root, there was a space in which all the exterior cells had become brown; but at no great distance rows of brown and colourless cells regularly alternated. In a third, rather thick, and in a fourth, thin root the alternation was extremely regular. Near the tip of a fifth (thin) rootlet two rows of a brown colour ran alongside one another in many places; but when these and other single rows were traced up the root, they changed into colourless rows, and afterwards reassumed their former character. Whenever the root-hairs were traced down to their bases, they were seen to arise from colourless cells. Neither granules nor brown fluid were observed in the parenchyma-cells nor in those surrounding the vascular bundle. Some roots which had been left in water for several days were |247| longitudinally striped with very faint brown lines; and one cell was observed which included granules; so that plain water produces some effect. These same roots, after being irrigated with a solution of 7 to 1000, were left for 24 hours; and now the longitudinal rows of brown cells had become much darker, and presented a much stronger contrast with the colourless cells. Several of the brown cells moreover included granules, which here and there were aggregated into small dark-brown rounded masses. Drosera, Dionæa, and Drosophyllum.—The roots of the plants belonging to these three closely allied genera are strongly acted on by a solution of carbonate of ammonia. In the case of a young plant of the Dionæa, all the exterior cells of the roots, after immersion for 24 hours in a solution of 4 to 1000, contained almost black or orange, or nearly colourless spheres and rounded masses of translucent matter, which were not present in the fresh roots. In this case, therefore, the exterior cells did not differ in alternate rows. Near the extremity of one of these roots many separate cells in the parenchyma, as seen in transverse sections, contained similar translucent spheres, but generally of an orange colour or colourless. The cells surrounding the vascular bundle abounded with much smaller dark-coloured spheres. Three main or leading roots of Drosophyllum lusitanicum were cut off and examined before being immersed in the solution, and no aggregated masses could be seen in them.

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Two were left for 22 hours in a solution of 4 to 1000, and they presented an extraordinarily changed appearance; for the exterior cells in many rows from the tips to the cut-off ends of the roots included either one large, or, more commonly, several spherical or oval, or columnar masses of brown translucent matter. The columnar masses had sinuous outlines, and appeared to have been formed by the confluence of several small spheres. The loose, or almost loose, oval cells composing the root-cap included similar brown spheres; and this fact deserves attention. Two rows of cells containing the just-described masses often ran up the root alongside one another; and sometimes there were three or four such adjacent rows. These alternated with others which were colourless, and contained either no solid matter, or rarely a few minute pale spheres. These roots were carefully examined; and all the many root-hairs arose from the colourless rows of cells, except in some few cases in which the cells on both sides abounded to an unusual |248| degree with aggregated masses; and here root-hairs arose from cells including a very few minute spheres. In longitudinal sections of the above roots, the cells in the parenchyma at different depths from the surface were seen to include spheres, but many of them were of small size and pale-coloured. There was no marked increase in the amount of aggregated matter in the cells closely surrounding the vascular bundle, as is so often the case with other plants. The third cut-off root was placed under the microscope, and was irrigated with a solution of 7 to 1000. After 13 minutes very small translucent granules could be seen in many of the cells; and after 35 minutes several cells near the cut-off end contained moderately large spheres of translucent matter. But I suppose that the solution was too strong; for the granules disappeared after about 45 minutes, except close to the tip; and the higher parts of the root no longer presented a striped appearance. Nevertheless the large spherical, oval, and oddly shaped masses in the cells near the cut-off end remained perfect, and they were watched for the next ¼ hours. During this time they slowly changed their shapes, but not afterwards, though observed for nearly 24 hours. For instance, two spheres in one cell became confluent and formed an oval mass; two other spheres ran together and formed a dumbbell-shaped body, which ultimately changed into a sphere; and, lastly, an irregular mass first became oval, then united itself with another oval mass, and both together became spherical. Saxifraga umbrosa.—This plant, from its affinity to the Droseraceæ, was cursorily observed. Many of the exterior cells of roots which had been immersed for 19 hours in a solution of 4 to 1000 were filled with brown granular matter. Only two or three cells in a longitudinal row were thus filled; but sometimes four or five such short rows were grouped together; and these groups alternated with rows of colourless cells. Sarracenia purpurea.—Two rootlets were left in water for 24 hours, but they presented no granules or aggregated masses. They were then irrigated with a solution of 7 to 1000, and in 20 minutes pale-brown aggregated masses could be distinctly seen near their tips. Two other, almost colourless, rootlets were left for 1 hour 10 minutes in the same solution; and now all the exterior cells contained brown granular matter, but much darker in some cells than in others. Some of the cells contained, |249| besides the granules, oval and occasionally spherical masses of transparent, almost colourless matter, which apparently did not change their shapes. The cells round the central vascular bundle included similarly shaped masses,

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but of a yellowish-brown colour. These roots and others were left for 24 hours in the solution of 7 to 1000, and their tips were now blackened. Some of the exterior cells, more especially those of the thicker roots, were filled with orange instead of brown granules; while other cells contained oval, spherical, or oddly shaped masses of orange, instead of almost colourless or pale-brown translucent matter. Some of these masses consisted of an aggregation of small, partially confluent spheres of different tints of orange. In transverse sections it could be seen that the two exterior layers of cells and those surrounding the vascular bundle contained the above-described masses, while the more central parenchymacells abounded with grains of starch. A solution of 4 parts of the carbonate to 1000 of water sufficed to produce similar effects. The root-hairs, after immersion in the solution, were not so transparent as is commonly the case, from including very fine granular matter, and from their shrunken protoplasmic lining being of a yellowish colour. The roots themselves were also usually opaque. Consequently the root-hairs were not easily traced down to their bases. They were distributed very unequally, being quite absent from the browner parts of the roots, while present on the parts which had remained pale-coloured. Notwithstanding this latter fact, it is very doubtful whether the rule of root-hairs arising almost exclusively from cells destitute of solid matter here holds good. Pelargonium zonale.—A fresh root was examined, and the cells contained no granules. It was then irrigated with a solution of 7 to 1000, and in about 15 minutes granules could be distinctly seen in the exterior cells in alternate rows. Two other rootlets, after being left in water for 48 hours, were not at all affected. They were then irrigated with the same solution and reexamined after 24 hours; and now the exterior cells in rows, as well as those surrounding the vascular bundle, abounded with granular matter. Other roots were left for 48 hours in a solution of 4 to 1000; and the cells near their tips were so packed with dark-brown granular matter as to be blackened. Higher up the roots, the granules were pale brown, translucent, irregularly rounded, and often more or less confluent. In some dark-coloured rootlets the |250| cells included a few small spheres of dark brown matter instead of granules. Usually the cells containing the granules formed single longitudinal rows, which alternated with rows of colourless cells. But occasionally several adjoining rows included granules; thus in one place two adjacent rows of cells with granules were succeeded by an empty row; this by two alternations of granules and empty rows; then came two adjoining rows with granules, an empty row, and three adjoining granular rows. In another place an empty row was succeeded by five adjoining rows with granules; these by an empty row; this by three adjoining rows with granules, and this by an empty row. After many casual observations, in which all the root-hairs appeared to arise from cells destitute of granules, this was found to be the case with 50 hairs which were traced down to their bases. With one problematical exception, not a single hair could be found which arose from a cell containing granules. In this one exceptional case, a hair seemed to spring from the transverse wall separating two cells; but with a good light and under a high power, the wall apparently consisted of two walls, separated by an excessively narrow clear space, as if a cell had here failed to be fully developed. The solution likewise caused the precipitation

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of granules in the elongated cells surrounding the vascular bundle, and in some tubes or ducts within the bundle. The solution apparently does not act on cells which have been killed. The ends of a root were torn open, so that the vascular bundle was fully exposed; the root was then left for 24 hours in a strong solution of 7 to 1000, and no granules were deposited in the exposed cells round the vascular bundle; but by tearing open fresh parts of the same roots, these cells were found full of granules. The granules were not dissolved by immersion for 24 hours in alcohol; but they were dissolved by a cold solution of caustic potash. The dissolution, however, took place very slowly; for though on two occasions the granules wholly, or almost wholly, disappeared after an immersion of 20 hours, yet with a thicker root they were not dissolved, though rendered browner, by an immersion for this length of time; but they finally disappeared after 18 additional hours in a fresh solution of the potash. In the cells round the vascular bundle, from which the granules had been dissolved by the potash, matter resembling oil-globules in appearance remained. |251| Lastly, two drops of a 1-per-cent. solution of osmic acid were added to ½ oz. of distilled water, and some roots were left in this fluid for 20 hours. They were affected in very different degrees. Some were only a little discoloured; and in such roots a single exterior cell here and there contained either blackish granules or small black spheres. Other roots were much blackened; and in these longitudinal rows of dark brown or blackened cells plainly alternated with colourless rows. The cells surrounding the vascular bundle and many of the parenchyma-cells also contained blackened granules. Hence it is probable that carbonate of ammonia likewise acts on some of the parenchyma-cells; but if so, the fact was overlooked, or accidentally not recorded, in my notes. Oxalis Acetosella.—Roots were first examined, and then placed in a solution of 7 to 1000. Some slight degree of aggregation was seen in a few minutes. After 30 minutes all the cells near the tips contained rounded accumulations of granules. Higher up in one of the roots, single cells, or from two to five cells in a row, were filled with minute hyaline globules. In some places these had become confluent, so that they formed larger globules having a sinuous outline. The cells underlying the exterior layer likewise contained extremely fine granular matter. Still higher up the same root there were considerable spaces in which none of the cells contained granules. But again higher up, the granules reappeared. The root-hairs were numerous; but not one was seen which arose from a cell containing granules. Roots of Oxalis sepium, comiculata, and of a greenhouse species with small yellow flowers were immersed in a solution of 7 to 1000, and granular matter was deposited in the layer of cells underlying the exterior layer. This occurred in the case of O. sepium in 20 minutes. With O. corniculata the cells with granules were isolated—that is, did not form rows; and the granules were either brown or of a bluish-green colour. In the case of Oxalis (Biophytum) sensitiva, the exterior cells of the roots, after immersion for 44 hours in the same strong solution, were not much affected; but some of the deeper parenchyma-cells contained dark-brown translucent spheres, and the elongated cells round the vascular bundle were almost filled with granular matter.

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Fragaria (garden var. of the common strawberry).—Some white, almost transparent roots from a runner were examined (Dec. 12), and the cells contained no solid matter, except starch-grains. |252| They were then irrigated with a solution of 7 to 1000; and in from 10 to 15 minutes they became very opaque, especially near their tips. After being left a little time longer in the solution, longitudinal sections were made. The cells forming the exterior layer contained no solid matter, but the walls had become brown. There was much brown, finely granular matter in many of the parenchyma-cells at different depths from the surface; and these formed interrupted longitudinal rows, which alternated in the same zone with rows of empty colourless cells. Almost all the endoderm-cells likewise contained granules. In the parenchyma the cells which included much granular matter contained no starch-grains; while those abounding with starch-grains contained only a few or no granules. The fact was best seen after the sections had been irrigated with a solution of iodine; and they then presented a very remarkable appearance, considering how homogeneous they had been before being treated with the ammonia and iodine; for the fine granular matter was rendered still browner and the starch-grains of a beautiful blue. These roots were left for a week in diluted alcohol, and the granules were not dissolved. Not a single root-hair could be found on these roots. A rooted stolon was therefore dug up and potted on Dec. 12th; it was then forced forwards in the hot-house, and afterwards kept very dry. When examined on Jan. 3rd the roots were found clothed with innumerable root-hairs; and they were then left for 23 hours in the solution of 7 to 1000. Sections of the thicker roots presented exactly the same appearances as described above; and the exterior cells, from which the root-hairs arose, were destitute of granules. The thinner roots differed somewhat in appearance, as the parenchyma-cells did not contain any fine granules, but in their places small, spherical, or oval, or irregularly-shaped masses or filaments of brown translucent matter, resembling a highly viscid fluid. There were also in these cells other still smaller colourless spheres. The cells, however, close to the tip of the root were filled with brown granular matter. Solanum (capsicastrum ?, var. Empress).—Roots, after an immersion of 20½ hours in a solution of 4 to 1000, were split longitudinally and examined, but with no great care. The exterior cells did not appear to have been affected; but some of the parenchyma-cells close beneath the exterior cells contained minute aggregated masses of brown, opaque, or sometimes hyaline granules. Moreover |253| many, but by no means all, of the elongated cells surrounding the vascular bundle included dark-brown fine granular matter. Three roots which had been left in water for the same length of time, viz. 20½ hours, were similarly examined, but their cells presented none of the above appearances. Primula acaulis.—Several roots were left (Dec. 22) for 18 hours in a solution of 4 to 1000, and they were all much affected, except some of the thinnest rootlets. Many of the exterior cells contained granules within the shrunken protoplasmic utricle, which had contracted into one, two, or even three, oval or spherical bags, lying within the same cell. The rows of cells containing the granules showed some tendency to alternate with rows of empty cells. The granules were rendered orange-brown by iodine. The innumerable root-hairs all arose from the empty cells; and I saw only two partial exceptions, in which

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the outer walls of cells containing granules were produced into short papillæ, as in the formerly described case of Phyllanthus, and these resembled nascent root-hairs. Within one of these papillæ, granules surrounded by the shrunken utricle could be seen. In the parenchyma single cells were seen containing minute hyaline globules, which were colourless or pale or dark blue, or occasionally greenish or yellowish. Many of the endoderm-cells likewise contained more or less confluent hyaline globules; but these were colourless, and larger than those in the parenchyma. They resembled starch-grains so closely that they were tried with iodine, but were not coloured blue. Roots which had been kept for 48 hours in water exhibited none of the coloured or colourless globules; but these appeared when the roots were afterwards immersed for 24 hours in the ammonia solution. Although it is certain that granules were deposited in the exterior cells in the case just described, yet in four other roots, after an immersion of 24 hours in the solution, no granules could be seen in any of the exterior cells. Some of the parenchyma-cells, however, were of a fine blue colour, and contained many globules or granules, but no starch-grains, while others contained starch-grains as well as some few globules. Cyclamen persicum.—Sections taken from roots of this plant which had been immersed in a solution of carbonate of ammonia presented an extraordinary different appearance from those of fresh roots. All the cells in the latter appeared empty, excepting those of the endoderm, which sometimes included a few very fine pale-coloured |254| granules, unlike those in the same cells after immersion.

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Thick and thin roots were left for 22 hours in a solution of 7 to 1000, and the cells forming the exterior layer were filled over considerable spaces with green granules, while over other spaces they were empty. The granular and empty cells did not form regular alternate rows, as occurs in so many other plants; yet, as we shall presently see, there is occasionally some degree of alternation. The exterior cells with the green granules were so numerous in certain cases, that roots which had been pale brown before immersion were afterwards distinctly green. The green granules sometimes became aggregated into spherical, or oval, or elongated masses having a sinuous outline; and some of these are shown within the root-hairs in fig. 2. Many of the cells of the parenchyma, either standing separately or two or three in a row (as shown in fig. 1), contain similar green, or sometimes brownish, granules. Almost all the narrow elongated cells of the endoderm (b, fig. 1) likewise contain these granules, with merely here and there an empty cell. Although both kinds of cells often appear as if gorged with the granules, yet these really form only a layer adhering to the inside of the protoplasmic utricle, as could be seen when cells had been cut through. With some thick fleshy roots, after an immersion for 42 hours (and thick roots require a long immersion for the full effect to be produced) the green granules in the parenchyma-cells had become completely confluent, and now formed spheres of transparent green matter of considerable size. The granules are not dissolved, nor is their colour discharged by sulphuric ether. Acetic acid instantly changes the green into a dull orange tint. The granules are not dissolved by alcohol. Their precipitation by the ammonia solution seems to depend on the life of the cell; for some transverse sections were examined and found colourless, as well as destitute of granules. They were then irrigated with a solution of 7 to 1000, and reexamined after 22 hours; and only a very few cells in two out of the five sections showed any trace of colour, which, oddly enough, was blue instead of green. The few coloured cells occurred exclusively in the thickest parts of the sections, where the central ones would obviously have had

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the best chance of keeping alive for some time. In these coloured cells a little very fine granular matter could be distinguished. On most of the roots root-hairs were extremely numerous, |256| and they generally arose from cells destitute of granules; yet in many places whole groups of cells abounding with granules gave rise to well-developed root-hairs. Therefore the rule which holds good with so many plants, namely, that root-hairs arise exclusively from colourless cells destitute of granules, here quite breaks down. The granules extend from the cells into the hairs which spring from them, as is shown in fig. 2; and they here sometimes become confluent, forming rounded or elongated masses of transparent green matter. This matter within the tips of some of the hairs seemed to pass into a brownish fluid. It was repeatedly observed that where many hairs rose close together from cells containing the green granules, the tips of the hairs were glued together by cakes or masses of orange-coloured translucent tough matter. This matter could be seen, under favourable circumstances, to consist either of very thin homogeneous sheets or of aggregated granules. It was not acted on by an immersion of two hours in absolute alcohol or in sulphuric ether. The smaller globules were either dissolved or destroyed by sulphuric acid, while others were rendered highly transparent. The formation of this orange-coloured matter is independent of the previous action of ammonia; and I have noticed similar matter attached to the rootlets of many other plants. It is probably formed by the softening or liquefaction of the outer surface of the walls of the hairs, and the subsequent consolidation of the matter thus produced.* Nevertheless some appearances led me to suspect that the brownish fluid which was seen within the tips of the hairs enclosing the green granules may perhaps exude through the walls, and ultimately form the cakes of orange matter. A few other solutions were tried. Roots were left for from 20 to 43 hours in a solution of 7 parts of pure carbonate of soda to 1000 of water, and in no case were granules deposited in the exterior cells; but some of these cells in longitudinal rows became brown; these alternated with rows of colourless cells. In one instance several of these cells included oval or spherical masses of an apparently tenacious fluid of a brown tint. Single cells in the parenchyma likewise became brown; others were dotted, like a mezzotinto engraving, with barely distinguishable granules, which, |257| however, in other cells were plainly visible; and, lastly, a few of these cells included spherical or oval masses of the same nature as those just mentioned in the exterior cells. Most or all of the endoderm-cells either contained a homogeneous brown fluid, or they appeared, from including excessively fine granules, like a mezzotinto engraving. In no case were any of the cells coloured green. Some roots were immersed for from 20 to 44 hours in a solution of carbonate of potash of 7 to 1000; and these were affected in nearly the same manner as those in the soda solution. In the exterior cells, however, more granules were deposited; and these were oftener aggregated together, forming transparent orange-coloured spheres. The cells containing the granules or spheres were of a brown colour, and were arranged in longitudinal rows which *

See some remarks on this liquefaction of the outer surface of root-hairs by my son Francis and myself in ‘The Power of Movement in Plants,’ 1880, p. 69.

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alternated with rows of colourless cells. There were fewer granules in the parenchymacells than in the roots which had been subjected to the soda solution; and there were none in the endoderm-cells, even in roots which had been left immersed for 44 hours. A solution of phosphate of ammonia (4 to 1000) produced no effect on the roots after 43 hours’ immersion. Concluding Remarks.—The most remarkable conclusion which follows from the foregoing observations is that, in the roots of various plants, cells appearing quite similar and of the same homologous nature yet differ greatly in their contents, as shown by the action on them of certain solutions. Thus, of the exterior cells, one, two, or more adjacent longitudinal rows are often affected; and these alternate with rows in which no effect has been produced. Hence such roots present a longitudinally striped appearance. Single cells in the parenchyma, or occasionally two or three in a row, are in like manner affected; and so it is with the endoderm-cells, though it is rare when all are affected. The difference in aspect between sections of roots before and after their immersion in a proper solution is sometimes extraordinarily great. Of all the solutions tried, that of carbonate of ammonia acts most quickly, indeed almost instantaneously; and in all cases the action travels up the root from cell to cell with remarkable rapidity. With Euphorbia Peplus a solution of 1 part of the carbonate to 10,000 of water acted, though not very quickly. When the action is very slight, the fluid contents of the cells are merely rendered pale brown. Nevertheless, judging from the gradations which could be observed, the brown tint is probably |258| due to the presence of invisibly minute granules. More commonly distinctly visible granules are deposited, and these, in the case of Cyclamen persicum, adhered to the inner surface of the protoplasmic utricle; and this probably is the case with other plants. From granules we are led on to globules more or less confluent, and thence to spherical or oval or oddly shaped masses of translucent matter. These were coloured pale or dark blue or green in seven of the genera experimented on; but usually they are brownish. The granules or globules are not acted on, except as far as colour is concerned, by alcohol, sulphuric ether, a solution of iodine, or acetic acid; but they are slowly dissolved by caustic potash. It has been shown in a previous paper that in the leaves of certain plants carbonate of ammonia first causes the deposition of granules from the cell-sap, which aggregate together, and that matter is afterwards withdrawn from the protoplasmic utricle which likewise undergoes aggregation. Something of the same kind apparently occurs in roots, judging from the occasional difference in colour of the aggregated masses within the same cell, and more especially from what has been described as occurring in the root-cells of Sarracenia and Pelargonium. Other solutions besides that of carbonate of ammonia induce nearly, but not quite, the same effects. Phosphate of ammonia acted more slowly than the carbonate on the roots of Euphorbia Peplus, and not at all on those of Cyclamen. With this latter plant and with the Euphorbia carbonate of soda was efficient, but in a less degree than the carbonate of ammonia. In one trial which was made, carbonate of potash acted on the exterior cells, but hardly at all on those of the parenchyma and endoderm. An extremely weak solution of osmic acid was highly potent, and the deposited granules were blackened. This acid is poisonous; but it must not be supposed that the mere death of a cell induces deposition. This

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is far from holding good; so that, judging from several trials, cells which have been killed are not acted on even by carbonate of ammonia, which is the most efficient of all known agents. I have not sufficient data to judge how generally roots are acted on by the carbonate of ammonia in the manner described. Those of 49 genera, many of which belong to widely separated families, were tried. The roots of 15 were conspicuously acted on, those of 11 in a slight degree, making together 26 genera; |259| while those of the remaining 23 genera were not affected, at least in any plain manner. But it should be stated that sections of all these latter roots were not made, so that the cells of the parenchyma and endoderm were not examined. We may therefore suspect that if various other reagents had been tried, and if sections had been made of all, some effect would have been observed in a larger proportional number of cases than actually occurred. I have elsewhere shown that the contents of the glandular hairs and of the epidermic and other cells of the leaves undergo aggregation in a considerable number of plants when they are acted on by carbonate of ammonia; and the roots of these same plants are especially liable to be affected in the same manner. We see this in 7 out of the 15 genera which had their roots conspicuously affected coming under both heads. The question naturally arises, what is the meaning of matter being precipitated by a solution of carbonate of ammonia and of some other substances in certain cells and not in other cells of the same homologous nature? The fact of granules and spherical masses being formed within the loose exfoliating cells of the root-cap, as was observed in several instances, and conspicuously in that of Drosophyllum, apparently indicates that such matter is no longer of any use to the plant, and is of the nature of an excretion. It does not, however, follow that all the aggregated matter within the root-cells is of this nature, though the greater part may be; and we know that in the filaments of Spirogyra not only are granules deposited from the cell-sap which aggregate into spheres, but that the spiral chlorophyllbands also contract into spherical or oval masses. The view that the granules consist of excreted matter is supported, to a certain extent, by their not being redissolved, as far as I could judge, in the roots of living plants of Euphorbia Peplus; and in this respect they differ in a marked manner from the aggregated matter in the leaves of Drosera and its allies. A larger amount of granular matter is deposited close to the tip of the root than elsewhere; and it might have been expected that where growth with the accompanying chemical changes was most rapid, there the largest amount of excreted matter would accumulate. It also deserves notice that there exists some degree of antagonism between the presence of these granules and of starch-grains in the same cells. On the other hand, it must be admitted that no excretion in the vegetable kingdom, as far as is at present known, remains dissolved |260| in the cell-sap, or, as in the present cases, is precipitated only through the action of certain reagents. On the view here suggested the exterior cells in many rows, some parenchyma-cells, and many or most of the endoderm-cells serve as receptacles for useless matter. It will, however, at first appear highly improbable that so many cells should serve for such a purpose. But this objection has no great weight; for in certain cases a surprising number of cells may be found which, instead of containing chlorophyll-grains like the surrounding cells, are filled with

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crystalline masses of carbonate of lime and other earthy salts which are never redissolved. Many isolated cells or rows of cells likewise contain gummy, resinous, or oily secretions and other substances, which, it is believed, are of “no further use in the changes connected with nutrition or growth”.* We thus see that useless or excreted matter is commonly collected in separate cells; and we thus get a clue, on the view here suggested, for understanding why the deposited granules and spherical masses are found in isolated cells or rows of cells, and not in the other cells of the same homologous nature; and this is the circumstance which, as lately remarked, at first surprised me most. In the roots of plants the endoderm-cells commonly separate those of the parenchyma from the vascular bundle. Very little is known about their use or functions; so that every particular deserves notice. They resemble the exterior cells in their walls partly consisting of corky or cuticularized matter;† and we have here seen that they likewise resemble the exterior cells by serving as receptacles for the deposited granular matter, which, in accordance with our view, must be excreted from the inner parenchyma-cells or from the vascular bundle. The fact of the granules being deposited in the exterior cells in one, two, or more adjacent longitudinal rows, which alternate with rows destitute of granules, is the more remarkable, as close to the tip of the root all the exterior cells are commonly gorged |261| with granular matter. It appears, therefore, that matter of some kind must have passed laterally from those rows which do not contain granular matter, after being acted on by the ammonia, into the adjoining rows. Why the useless matter should not pass out of the root through the outer walls of the cells, probably depends on the thickness and cuticular nature of the outer walls. Pfeffer states that root-hairs are developed on the gemmæ, and apparently on the thallus, of Marchantia polymorpha from superficial cells which, even before the growth of the hairs, do not contain starch- or chlorophyll-grains; although these bodies are present together with matter of an unknown nature in the adjacent superficial cells. He has observed a nearly similar case with the roots of Hydrocharis.‡ No one else seems to have even suspected that root-hairs were not developed indifferently from any or all of the exterior cells. But it has now been shown that with many plants, with only one marked exception, namely that of Cyclamen, the root-hairs arise exclusively from cells in which granular matter has not been deposited after the action of certain solutions. This relation between the presence of hairs and the contents of the cells cannot be accounted for by matter, which would have been deposited if the roots had been subjected to a proper solution, having been consumed in the formation of the hairs; and this notion is wholly inapplicable to the cases described by Pfeffer. May we believe that cells filled with effete matter become unfitted for absorbing or

*

† ‡

Sachs, ‘Text-Book of Botany’ (Engl. transl.), 1875, p. 113. [Sachs 1875.] Also De Bary, ‘Vergleichende Anatomie,’ pp. 142–143. [Bary 1877.] When odoriferous oils or other strongly tasting or poisonous substances are deposited in cells, and are thus thrown out of the active life of the plant, there is reason to believe that they are by no means useless to it, but indirectly serve as a protection against insects and other enemies. On the nature of endoderm-cells, see De Bary, ‘Vergleichende Anatomie,’ 1877, p. 129. ‘Arbeiten des botan. Instituts in Würzburg,’ Band i. p. 79. [Pfeffer 1874.]

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transmitting water with the necessary salts, and do not therefore develop root-hairs? Or is the absence of hairs from the cells which contain the deposited matter due merely to the advantage which is commonly derived from a physiological division of labour? This and many other questions about the cells, in which granules or larger masses of translucent matter are deposited after certain solutions have been absorbed, cannot at present be answered. But I hope that some one better fitted than I am, from possessing much more chemical and histological knowledge, may be induced to investigate the whole subject.

1 2 3

Petty Spurge. Sydney Howard Vines (1849–1934), botanist and Fellow of Christ’s College, Cambridge, 1876. The Spurge family.

1882. On the dispersal of freshwater bivalves. Nature 25 (6 April): 529–30. F1802 The wide distribution of the same species, and of closely-allied species of freshwater shells must have surprised every one who has attended to this subject. A naturalist, when he collects for the first time freshwater animals in a distant region, is astonished at their general similarity to those of his native European home, in comparison with the surrounding terrestrial animals and plants. Hence I was led to publish in Nature (vol. xviii. p. 120)1 a letter to me from Mr. A. H. Gray, of Danversport, Massachusetts, in which he gives a drawing of a living shell of Unio complanatus, attached to the tip of the middle toe of a duck (Querquedula discors) shot on the wing. The toe had been pinched so hard by the shell that it was indented and abraded. If the bird had not been killed, it would have alighted on some pool, and the Unio would no doubt sooner or later have relaxed its hold and dropped off. It is not likely that such cases should often be observed, for a bird when shot would generally fall on the ground so heavily that an attached shell would be shaken off and overlooked. I am now able to add, through the kindness of Mr. W. D. Crick,2 of Northampton, another and different case. On February 18 of the present year, he caught a female Dytiscus marginalis,3 with a shell of Cyclas cornea clinging to the tarsus of its middle leg. The shell was .45 of an inch from end to end, .3 in depth, and weighed (as Mr. Crick informs me) .39 grams, or 6 grains. The valves |530| clipped only the extremity of the tarsus for a length of .1 of an inch. Nevertheless, the shell did not drop off, on the beetle when caught shaking its leg violently. The specimen was brought home in a handkerchief, and placed after about three hours in water, and the shell remained attached from February 18 to 23, when it dropped off, being still alive, and so remained for about a fortnight while in my possession. Shortly after the shell had detached itself, the beetle dived to the bottom of the vessel in which it had been placed, and having inserted its antennæ between the valves, was again caught for a few minutes. The species of Dytiscus often fly at night, and no doubt they generally alight on any pool of water which they may see; and I have several times heard of their having dashed down on glass cucumber frames, no doubt mistaking the glittering surface for water. I do not

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suppose that the above weight of 6 grains would prevent so powerful an insect as a Dytiscus from taking flight. Anyhow this beetle could transport smaller individuals; and a single one would stock any isolated pond, as the species is an hermaphrodite form. Mr. Crick tells me that a shell of the same kind, and of about the same size, which he kept in water “extruded two young ones, which seemed very active and able to take care of themselves.” How far a Dytiscus could fly is not known; but during the voyage of the Beagle a closely-allied form, namely, a Colymbetes, flew on board when the nearest point of land was forty-five miles distant; and it is an improbable chance that it had flown from the nearest point.4 Mr. Crick visited the same pond a fortnight afterwards, and found on the bank a frog which appeared to have been lately killed; and to the outer toe of one of its hind legs a living shell of the same species was attached. The shell was rather smaller than in the previous case. The leg was cut off and kept in water for two days, during which time the shell remained attached. The leg was then left in the air, but soon became shrivelled; and now the shell being still alive detached itself. Mr. F. Norgate,5 of Sparham, near Norwich, in a letter dated March 8, 1881, informs me that the larger water-beetles and newts in his aquarium “frequently have one foot caught by a small freshwater bivalve (Cyclas cornea ?), and this makes them swim about in a very restless state, day and night, for several days, until the foot or toe is completely severed.” He adds that newts migrate at night from pond to pond, and can cross over obstacles which would be thought to be considerable. Lastly, my son Francis, while fishing in the sea off the shores of North Wales, noticed that mussels were several times brought up by the point of the hook; and though he did not particularly attend to the subject, he and his companion thought that the shells had not been mechanically torn from the bottom, but that they had seized the point of the hook. A friend also of Mr. Crick’s tells him that while fishing in rapid streams he has often thus caught small Unios. From the several cases now given, there can, I think, be no doubt that living bivalve shells must often be carried from pond to pond, and by the aid of birds occasionally even to great distances. I have also suggested in the “Origin of Species” means by which freshwater univalve shells might be far transported.6 We may therefore demur to the belief doubtfully expressed by Mr. Gwyn Jeffreys in his “British Conchology,’ namely, that the diffusion of freshwater shells “had a different and very remote origin, and that it took place before the present distribution of land and water.”7 Charles Darwin

1 2 3 4 5 6 7

Darwin 1878, F1783 (p. 422). Walter Drawbridge Crick (1857–1903), shoe manufacturer, amateur geologist, palaeontologist and grandfather of Francis Crick (1916–2004). The great diving beetle. See Darwin’s insects p. 59. This case was also cited in Origin p. 386. CD died thirteen days after this was published. Francis Norgate, ornithologist. Origin 6th ed., p. 345. John Gwyn Jeffreys (1809–85), conchologist, zoologist and lawyer. Jeffreys 1862, p. lxxx.

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1882. Preliminary notice. In Van Dyck, [W. T.], On the modification of a race of Syrian street-dogs by means of sexual selection. With a preliminary notice by Charles Darwin, F. R. S., F. Z. S. [Read 18 April] Proceedings of the Zoological Society of London no. 25: 367–9. F1803 (Received April 4, 1882.) Most of the naturalists who admit that natural selection has been effective in the formation of species, likewise admit that the weapons of male animals are the result of sexual selection—that is, of the best-armed males obtaining most females and transmitting their masculine superiority to their male offspring. But many naturalists doubt, or deny, that female animals ever exert any choice, so as to select certain males in preference to others. It would, however, be more correct to speak of the females as being excited or attracted in an especial degree by the appearance, voice, &c. of certain males, rather than of deliberately selecting them. I may perhaps be here permitted to say that, after having carefully weighed to the best of my ability the various arguments which have been advanced against the principle of sexual selection, I remain firmly convinced of its truth. It is, however, probable that I may have extended it too far, as, for instance, in the case of the strangely formed horns and mandibles of male Lamellicorn beetles, which have recently been discussed with much knowledge by W. von Reichenau,* and about which I have always felt some doubts. On the other hand, the explanation of the development of the horns offered by this entomologist does not seem to me at all satisfactory. |368| In order to ascertain whether female animals ever or often exhibit a decided preference for certain males, I formerly inquired from some of the greatest breeders in England, who had no theoretical views to support and who had ample experience; and I have given their answers, as well as some published statements, in my ‘Descent of Man’.† The facts there given clearly show that with dogs and other animals the females sometimes prefer in the most decided manner particular males—but that it is very rare that a male will not accept any female, though such cases do occur. The following statement, taken from the ‘Voyage of the Vega,’‡ indirectly supports in a striking manner the above conclusion. Nordenskiöld1 says:—“We had two Scotch collies with us on the ‘Vega.’ They at first frightened the natives very much with their bark. To the dogs of the Chukches2 they soon took the same superior standing as the European claims for himself in relation to the savage. The dog was distinctly preferred by the female Chukch canine population, and that too without the fights to which such favour on the part of the fair commonly gives rise. A numerous canine progeny of mixed Scotch-Chukch breed has arisen at Pitlekay. The young dogs had a complete resemblance to their father; and the natives were quite charmed with them.”

* † ‡

“Ueber den Ursprung der secundãren mãnnlichen Geschlechtscharakteren &c.,” Kosmos, Jahrgang v. 1881, p. 172. [Wilhelm von Reichenau (1847–1925), German army officer (until 1879) and naturalist. Reichenau 1881.] The Descent of Man, second edit. (1874), part ii. Chap. xvii. pp. 522–525. See also Chap, xiv., on choice in pairing shown by female birds, and on their appreciation of beauty. The Voyage of the Vega,’ Eng. translat. (1881), vol. ii. p. 97.

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What the attractions may be which give an advantage to certain males in wooing in the above several cases, whether general appearance, such as colour and form, or vigour and strength, or gestures, voice, or odour, can rarely be even conjectured; but whatever they may be, they would be preserved and augmented in the course of many generations, if the females of the same species or race, inhabiting the same district, retained during successive generations approximately the same general disposition and taste; and this does not seem improbable. Nor is it indispensable that all the females should have exactly the same tastes: one female might be more attracted by some one characteristic in the male, and another female by a different one; and both, if not incompatible, would be gradually acquired by the males. Little as we can judge what are the characteristics which attract the female, yet, in some of the cases recorded by me, it seemed clearly to be colour; in other cases previous familiarity with a particular male; in others exactly the reverse, or novelty. With respect to the first appearance of the peculiarities which are afterwards augmented through sexual selection, this of course depends on the strong tendency in all parts of all organisms to present slight individual differences, and in some organisms to vary in a plain manner. Evidence has also been given in my book on Variation under Domestication showing that male animals are more liable to vary than females; and this would be highly favourable to sexual selection. Manifestly every slight individual difference and each more conspicuous variation depends on definite though unknown |369| causes; and these modifications of structure &c. differ in different species under apparently the same conditions. Statements of this nature have sometimes been misinterpreted, as if it were supposed that variations were indefinite or fluctuating, and that the same variations occurred in all species. In reference to sexual selection, I will here only add that the complete manner in which the introduced dogs and other domestic animals in South America and other countries have been mongrelized, so that all traces of their original race have been lost, often appeared to me a surprising fact. This holds good according to Rengger* with the dogs even in so isolated a country as Paraguay. I formerly attributed this mongrelization merely to the breeds not having been kept separate and to the greater vigour of cross-bred offspring; but if the females often prefer strangers to their old companions, as seems to be the case, according to Nordenskiöld, in Siberia, and in Syria as shown in the following essay, then we can readily understand how rapid and complete would be the progress of mongrelization. I will now give without further comment the essay which Dr. W. Van Dyck, Lecturer on Zoology to the Protestant College at Beyrout, who has had excellent opportunities for observations during a residence of twenty years, has been so kind as to send me. [Van Dyck’s 3 essay, pp. 369–370, omitted here, gives examples of Syrian bitches which mated preferentially with foreign dogs rather than their own breed.]

*

‘Naturgeschichte der Sãugethiere von Paraguay,’ 1830, p. 154. [Johann Rudolph Rengger (1795–1832), German physician, explorer and naturalist. Rengger 1830.]

490

1

2

3

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Nils Adolf Erik Nordenskiöld (1832–1901), Finnish-born explorer and scientist in exile in Sweden from 1857. He navigated the ‘North-east passage’ on the Vega from Norway to the Bering Strait (1878–80) and described his journey in several books. Nordenskiöld 1881. Peoples of the Chukchi Peninsula, the north-eastern extremity of Asia, bordered by the East Siberian Sea and the Bering Sea. William Thomson Van Dyck (1857–1939), American physician, ornithologist and lecturer on materia medica and hygiene at the Syrian Protestant College, Beirut 1880–82. See CD to Van Dyck LL 2: 253, CD’s draft of this notice is in DAR28.2.C1–C5.

1883. Prefatory notice. In Müller, H., The fertilisation of flowers. Translated and edited by D’Arcy W. Thompson. With a preface by Charles Darwin. London: Macmillan, pp. [vii]–x. F1432 The publication of a translation of Hermann Müller’s Die Befruchtung der Blumen &c.,1 will without doubt be a great service to every English botanist or entomologist who is interested in general biological problems. The book contains an enormous mass of original observations on the fertilisation of flowers, and on the part which insects play in the work, given with much clearness and illustrated by many excellent woodcuts. It includes references to everything which has been written on the subject; and in this respect the English edition will greatly exceed in value even the original German edition of 1873, as Müller has completed the references up to the present time. No one else could have done the latter work so well, as he has kept a full account of all additions to our knowledge on this subject. Any young observer who, after reading the whole or part of the present work, will look, for instance, at the flower of a Salvia, or of some Papilionaceous or Fumariaceous plant, or at one of our common Orchids, will be delighted at the perfection of the adaptations by which insects are forced, unconsciously on their part, to carry pollen from the stamens of one plant to the stigma of another. Design in nature has for a long time deeply interested many men, and though the subject must now be looked at from a somewhat different point of view to what was formerly the case, it is not thus rendered the less interesting. |viii| Hermann Müller has by no means confined his attention to the manner in which pollen is carried by insects or other animals from plant to plant, for wind-fertilised flowers have been carefully described by him; and several curious transitions from the one state to the other are noticed. He has also attended more closely than any one else to the many contrivances for self-fertilisation [= self-pollination], which sometimes co-exist with adaptations for cross-fertilisation [=cross-pollination]. For instance, he has discovered the singular fact that with certain species two kinds of plants are regularly produced, one bearing inconspicuous flowers fitted for self-fertilisation, and the other kind with much more conspicuous flowers fitted for cross-fertilisation. The flowers on the first-mentioned plants serve the same end as the curious little closed cleistogamic2 flowers which are borne by a considerable number of plants, as described and enumerated in the present work. There is another interesting feature in the Befruchtung, by which it differs from all other works on the same subject; for it includes not only an account of the adaptation of flowers

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to insects, but of different insects to differently constructed flowers for the sake of obtaining their nectar and pollen. Any one who will carefully study the present work and then observe for himself, will be sure to make some interesting discoveries; and as the references to all that has been observed are so complete, he will be saved the disappointment of finding that which he thought was new was an already well-known fact. I may perhaps be permitted here to mention a few points which seem to me worthy of further investigation. There are many inconspicuous flowers which during the day are rarely or never visited by insects, and the natural inference seems to be that they must be invariably self-fertilised; for instance, this is the case with some species of Trifolium and Fumaria which bear very small flowers, with some species of Galium, Linum catharticum, &c. Many other such flowers are enumerated by Müller. Now it is highly desirable that it should be ascertained whether or not these flowers are |ix| visited at night by any of the innumerable individuals of the many species of minute moths. A lepidopterist while collecting at night, if endowed with only a small portion of the indomitable patience displayed by Müller, could ascertain this fact. The question possesses a considerable degree of theoretical interest; for if these inconspicuous flowers are never visited by insects, why, it may be asked, do they expand, and why is not the pollen protected by the petals remaining closed, as in the case of cleistogamic flowers? It would perhaps be possible to smear such small flowers with some viscid matter, and an examination of the petals would probably reveal nocturnal visits by moths by the presence of their scales; but it would be necessary to prove that the matter employed was not in itself attractive to insects. H. Müller gives long lists of the several kinds of insects which he has seen visiting various flowers in Germany; and it would be interesting to learn whether the same insects and the same proportional number of insects belonging to the different orders, visit the same plants in England as in Germany. There are many other subjects which it is desirable that some one should investigate, for instance, by what steps heterostylism (of which an account will be found in the present work) originated: and with trimorphic heterostyled plants we meet with a more extraordinary and complicated arrangement of the reproductive system than can be found in any other organic beings. In order to investigate this subject and several others, experiments in fertilisation would have to be tried; but these are not difficult and would soon be found interesting. For instance, there are some plants, the pistils and stamens of which vary much in length, and we may suspect that we here have the first step towards heterostylism; but to make this out, it would be necessary to test in many ways the power of the pollen and of the stigma in the several varieties. There exist also some few plants the flowers of which include two sets of stamens, differing in the shape of the anthers and in the colour of the pollen; and at present no one |x| knows whether this difference has any functional signification, and this is a point which ought to be determined. Again, there are other plants, for instance, the common Rhododendron, in which the shorter stamens are more or less rudimentary, and it has been asserted that seedlings raised from pollen taken from the short and from the full-sized stamens differ in appearance; and it would be of importance to know whether they differ in their fertility or power of yielding seeds. It would also be interesting to learn whether in the plants, already alluded to, which produce two forms, one adapted for

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self-fertilisation and the other for cross-fertilisation, the reproductive organs have become in any degree differentiated, so that their action would not be perfect if the two forms were reciprocally crossed. Would a flower adapted for self-fertilisation yield a full complement of seed if fertilised by pollen from one adapted for cross-fertilisation; and vice-versâ with the other form? But it would be superfluous to make any further suggestions. These will occur in abundance to any young and ardent observer who will study Müller’s work and then observe for himself, giving full play to his imagination, but rigidly checking it by testing each notion experimentally. If he will act in this manner, he will, if I may judge by my own experience, receive so much pleasure from his work, that he will ever afterwards feel grateful to the author and translator of the Befruchtung der Blumen. Charles Darwin. Down, February 6, 1882.

1 2

Müller 1873. Automatic self-pollination.

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of the voyage of the Beagle, under the command of Capt. Fitzroy, R.N. during the years 1832 to 1836. London: Smith Elder and Co. (DO) W. B. N. 1847. Native Patagonian salt. Gardeners’ Chronicle no. 8 (20 February), p. 117. (DO) W. X. W. 1861. Asarum virginicum. Journal of Horticulture and Cottage Gardener n.s. 1: 244. Wallace, Alfred Russel. 1872. The last attack on Darwinism. Nature 6 (25 July) 237–239. 1873. Inherited feeling. Nature 7 (20 February): 303. 1879. Colour in nature [Review of Allen 1879]. Nature 19 (3 April): 501–5.* 1905. My life: A record of events and opinions. 2 vols. London: Chapman and Hall. (DO)* Walters, Stuart Max. 1981. The shaping of Cambridge botany. A short history of wholeplant botany in Cambridge from the time of Ray into the present century. Cambridge: University Press.* Waterhouse, George Robert. 1846. A natural history of the mammalia. vol. 1, Marsupiata, or pouched animals. London: Hippolyte Bailliere. Weismann, August. 1875–6. Studien zur Descendenz-Theorie. 2 vols. Leipzig: Wilhelm Engelmann. [Westwood, John Obadiah.] 1860. Doubtful permanence of cross-breeds. Gardeners’ Chronicle (14 January): 26. White, Adam. 1841. Descriptions of new or little known Arachnida. Annals and Magazine of Natural History 7: 471–477. (DO)* Wiegmann, Arend Friedrich. 1828. Über die Bastarderzeugung im Pflanzenreiche. Eine von der königl. Akademie der Wissenschaften zu Berlin gekrönte Preisschrift. Brunswick: Friedrich Vieweg. Wilson, Robert. ed. 1806. Voyages of discoveries round the world; successively undertaken by the Hon. Commodore Byron, in 1764; Captains Wallis and Carteret, in 1766; and Captain Cook in the years 1768 to 1789 inclusive. The whole carefully selected from the Journals of the respective commanders. 3 vols. London: James Cundee. Winch, Donald. 2001. Darwin fallen among political economists. Proceedings of the American Philosophical Society 145, no. 4. (December): 415–437.* Winkler H., Christie D. A., Nurney D. 1995. Woodpeckers: a guide to the woodpeckers, piculets and wrynecks of the world. Robertsbridge: Pica Press.* [Woodbury, Thomas White.] 1860. Ligurian queens — M. Hermann’s “originals”. The Cottage Gardener and Country Gentleman 24 (6) (8 May): 94. Wyhe, John van. 2004. Phrenology and the origins of Victorian scientific naturalism. Aldershot: Ashgate.* ed. 2002–. The complete work of Charles Darwin online (http://darwin-online.org.uk/).* ed. 2005–. The Freeman bibliographical database. (http://darwin-online.org.uk/ Freeman_intro.html)* 2007. Mind the gap: Did Darwin avoid publishing his theory for many years? Notes and Records of the Royal Society 61: 177–205. (DO)* Youatt, William. 1834. Cattle: their breeds, management, and diseases. London: Baldwin & Cradock.* Zoology: Darwin, C. R. ed. 1838–43. The zoology of the voyage of H.M.S. Beagle. 5 vols. London: Smith Elder and Co. Zoology notes: Keynes, Richard Darwin. ed. 2000. Charles Darwin’s zoology notes & specimen lists from H.M.S. Beagle. Cambridge: University Press. (DO)*

Index

Abbot, Francis Ellingwood, 370 & n.1 Aborigines Protection Society: memorial on proposed South African Confederation, 416–17 Acland, Theodore D., 448 Adie, Alexander James, 218, 235 & 236 n.3 Agassiz, Louis, 80 n., 244 & n. & 244 n.1; glacier theory, 133 n.1, 159, 160, 141 & 147 n.5, 156, 218 & 234 n.6, 227, 363 & n.1 Agricultural Gazette: CD, scrofula and in-breeding, 407–8 Aldabra tortoise, protection of, 394–6 Alison, Robert Edward, 33 & 35 n. Alleloplasis darwinii: CD’s discovery of, 39 Allen, Grant, 426 & n.1 American Journal of Science and Arts, 329 n.1 American Naturalist: CD, letter on purportedly carnivorous bees, 428 & 429 n.1 Anderson, James, 329 & 330 nn.1 & 4 animal breeding: cross-breeding, CD’s questionnaire, 91–94 & 94 n.1; feet of otter hounds, 351 & n.1; penguin ducks, length of leg bones, 324 animal cruelty: CD appeals for abolition of steel traps, 339–90 & 340 n.2 animal experimentation, 398–9, 441–2, 442–3 Annals and Magazine of Natural History: W. Kemp, germination of ceeds in a sand-pit, 177–9 contributions by CD: Arachnidae, descriptions of, 133; caribideous insects collected by, 140; CD, discovery of Lophotus spp., 128; fertilisation of orchids, 360; fungus collected by, 140; description of ground-beetle, 140; review of G. R. Waterhouse, Natural history of the mammalia, 203–5; Sagitta, structure and propagation of, 167–71 & 172 n.1; terrestrial Planariae, 179–87 & 187 n.1 ants: perception in, 381 & n.2 Athenaeum, 281 n.1; CD, cut or uncut pages, 353–4 & 354 n.1; CD, defends theory of origin of species, 337; CD, reproductive power of elephants, 358 & n.1; CD, response to [R. Owen’s] review of W. B. Carpenter’s Foraminifera, 334–6 & 336 n.1 Atlantic dust, 230

Atriplex: germination of ceeds found in a sand-pit, 178–9 Audubon, John James, 380 & 381 n.10 auriculas: reversion, 312–13 Autobiography, 2 n.1,14 n.21, 126 n.1, 319 n.2, 322 n.1, 347 n.1, 364 n.1, 416 n.2, 428 n.1 Ayrton, Acton Smee, 373 & n.1 Azara, Felix d’, 31 & 32 n.2 Babington, Charles Cardale, 177 & 179 n.2 Bachman, John, 363 & 364 n.2 Bacon, Francis, 219 & 234 n.9 Baird, William, 251 & n.2 Baker, Charles, 23 & 30 n.20, 24, 25 Baker, N., 398 Bakewell, Robert, 285 & 296 n.14 Balbi, Gasparo, 37 & 39 n.1 Balch, Charles Leland, 369 & n.1 Barbier, Edmond, 427 & n.1 Baring, Francis Thornhill, 46 & 47 n.5 Barkley, Henry, 416 & 417 n.2 Barlett, Abraham Dee, 375 & 376 n.3 Bary, Anton de, 485 nn. Bates, Henry Walter, 334 n.1; Insect fauna of the Amazon valley, CD’s review of, 330–34 Bayfield, Henry Wolsey, 212 & 216 n.10 Beagle voyage, xv; Atlantic dust, CD’s observations of, 191–5; Beagle channel, 151, 158; Beagle Channel, Tierra del Fuego, 66, 131, 132; CD’s letters from, 2–14; CocosKeeling Islands, 46 n.1; R. FitzRoy, captain, 15, 32, 74, 147, 318; Fuegians on board, 16 & 30 n.3; guanaco, shot for meat, 172; J. S. Henslow recommends to R. FitzRoy, 318; W. Kent, Assistant Surgeon, 203 n.2; C. Martens, draughtsman, 32 n.4; rats and water-casks, 426; T. Sorrell, boatswain, 95 & 96 n.5; J. L. Stokes, naval officer and mate, 188 n.1; B. J. Sulivan, second Lieutenant, 203 n.1; in Tahiti, 18–22; J. Wickham, first Lieutenant, 426 & n.2; J. C. Wickham, First Lieutenant, 426 & n.2. See also CD, Beagle voyage; Journal of Researches

516

Index Beaton, Donald, 307–8 & 308 nn.1 & 5, 309 & 310 n.1, 314–15, 327 & nn.3 & 4, 328 & 329 n.2, 329 Beaumont, Elie de, 201 n., 229 & n. Bechstein, Johann Matthäus, 307 & n.4 Beechey, Frederick William, 21 & 30 n.15 bees: and fertilisation of holly, 404; and fertilisation of kidney beans, 267–8; and fertilisation of Papilionaceae, 272–7 & 277 n.1; humble bees, whether fertilised in the air, 316–17; instincts, 378; intercourse between common and Ligurian, 299; purportedly carnivorous, 428; size in Jamaica, 3120, 321; whether differing in parts of Great Britain, 319–20 Bell, John, 177 Belt, Thomas, 418 & 419 n.5 Bemmelen, Adrian Anthoni van, 407 n.1 Beneke, Friedrich Wilhelm, 456 & n. Bennett, Alfred William, 308 & 309 n.1, 360 & nn., 361 & n.1 Bennett, John Joseph, 283 & 295 n.7 Bennett, Mary, 416 n.3 Bentham, George, 281 n.1, 372 & 373 nn.2 & 3 Berkeley, Miles Joseph, 140, 189–90 & 190 n.1, 275 & 278 n.17, 328, 338; with CD, conducts experiments to discover effect of sea-water on germination of seeds, 258–65 Bertero, Carlo Giuseppe, 190 & 191 n.3 Bicknell, Henry, 28 & 31 n.27 Bienen Zeitung, 320 n.4 birds: duration of life, 363 & 364 n.1 Bischoff, Karl Gustav, 103 n., 104 n. Biscoe, John, 95 & 96 n.4 Bishop, Irving Prescott, 447 & 448 n.3 Blackadder, Alexander, 64 & 91 n.6, 81 Blyth, Edward, 429 & 430 n.4 Boat Memory, 30 n.3 Bolton, William, 247 & 249 n.3 Bond, Frederick, 302 & 303 n.1 Boner, Charles, 367 & nn.1 & 2 Bonney, George, 449 n.4 book publishing: cut or uncut pages, 353–4 bookselling: CD affirms freedom of booksellers to settle retain price, 243 Bory de Saint-Vincent, J. B. G. M., Dictionannaire classique d’histoire naturelle, 3 & 14 n.8 botany: bees, and fertilisation of kidney beans, 267–8; bees, and fertilisation of Papilionaceae, 272–7 & 277 n.1; carbonate of ammonia, action on chlorophyll-bodies, 453–69; carbonate of ammonia, action on roots of certain plants, 470–86; Catasetum tridentatum, sexual forms of, 321 & n.1; climbing plants, movements and habits, 347 & n.1; Cocos-Keeling Island plants, 45–6 & 46 n.1; cross-bred plants, 309–10; cross-fertilisation of papilionaceous flowers, 350–51; Cytisus scoparius, fertilisation of, 349; double flowers, origin of, 165–6 & 166 n.1; Drosera filiformis, power of, 393; Drosera,

517 irritability of, 303; Epipactis latifolia, appearance on CD’s gravel walk, 338; fertilisation of Cypripediums, 354–5 & 355 n.1; fertilisation of Fumariaceae, 389; fertilisation of wheat, 314–15; fertilisation of winter-flowering plants, 361; fungi collected by CD, 140; illegitimate unions of dimorphic and trimorphic plants, offspring of 356 & n.1; leaves injured by free radiation, 450; legumes, natural crosses, 256; Linum, two forms of, 329 & n.1; Medicago lupulina, note on, 3 48; movement of leaves, 443–5; movement of plants, 438–9; botany, nectar-secreting organs of plants, 250; fertilisation of orchids, 300–302 & 302 n.1, 305–6, 3 15–16, 329–30, 360; Lythrum salicaria, sexual relations of three forms of, 345 & n.1; orchids, fertilisation of, 300–302 & 302 n.1, 305–6, 315–16, 3 29–10, 360; Oxalis bowei, flower forms, 348–9; Pinguicula, irritability of, 394; pollen, influence on appearance of ceed, 327; pollination by humble-bees, 134–6; pollination by insects and butterflies, 418–19; Primula, dimorphism, 322 & n.1; Primula, three forms of, 355 & n.1; Pumilio argytolepsis, achenia, 303–5; salt-water and germination of ceeds, 246 & n.1, 247–9, 253–4, 258–65; ceeds, longevity of underground, 251–2 & 252 n.1, 254; self-fertilisation, 361; teasel, contractile filaments, 417–18; unisexual flowers, partial change of sex, 348–9; Usnea plicata, CD’s description of, 242; variation in flowers, causes of, 312–13; variegated leaves, 175 Boussingault, Jean Baptiste, 102 n., 115 & n., 118 n. Bowen, Augustus Frederick James, 212 & 216 n.10 Brayley, Edward William, CD’s testimonial for, 191 & n.1 Bree, Charles Robert, 373–4 & 374 n. Brent, Bernard Price, 309 & n.5 Brewster, David, 55 & 91 n.5, 56 British Association for the Advancement of Science (BAAS): British Museum, management of, 206–8 & 208 n.1; CD, list of cirripedia, 255–6; Edinburgh meeting, 1871, 398; queries respecting the human race, to be addressed to travellers, 128 & n.; Strickland committee, 162 & n.1, 269 British Medical Journal: CD, defence of D. Ferrier, 452 & n.1 British Museum: A. Günther, assistant keeper, Zoological Department, 396 n.1; integrity of collections, 296–7; management of, 206–7 & 208 n.1; purchase of fossils by, 46–7; Natural History collections, proposed severance of, 269–72 & 272 n.1, 278–81 & n.1, 364–5; G. R. Waterhouse, curator, 203 & 205 n.1; A. White, assistant, Zoology Department, 347–8 & 348 n.1 Bronn, Heinrich Georg, 335 & 337 n.5 Brown, Robert, 15 n.52, 205 & n.7, 300 & 302 n.3 Brown-Séquard, Charles Edouard, 448 & n.5 Brunton, Thomas Lauder, 379 & 390 n.5, 452 Buch, Christian Leopold, 218 & 234 n.5 bucket rope: CD seeks advice, 242 & n.1

518 Buckland, William, 209 & 216 n.7; glaciation in North Wales, 140 & 147 n.2, 143, 145–6 Bueno, Cosme, 107 & n. & 124 n.8 Bulletins de la Societé d’Anthropologie de Paris: CD, letter to J. L. A. de Quatrefages, 340–41 bumblebees. See humble-bees Burchell, William John, 31 & 32 n.3 Burmeister, Karl Hermann Konrad, 345 n. Burnes, Alexander, 194 n. Burnett, John, 193 n. Busby, James, 23 & 30 n.19, 24, 26 Butler, Arthur Gardiner, 431 & 432 n.2 Butler, Samuel, 427 & n.1 butterflies: sexual colours, 430–32 Byerbache [Edward Beyerbache?], Mr., 106 & 124 n.7 Bynoe, Benjamin, 158 n. Caldcleugh, Alexander: Chilean earthquake, 1835, 35 n., 40 & n., 41, 97 & 123 n.2, 101 & n., 106 & n., 108 Cambridge, CD’s first published word, 1 Cambridge Philosophical Society, 2 & 14 n.1 Cambridge Philosophical Transactions: J. F. Stephens, Chiasognarthus grantii, 9 & 15 n.44 Cambridge University: Greek, memorial advocating removal of from previous examination, 423 & 424 n.1; W. B. Dawkins candidate for Woodwardian Professorship of Geology, 376 & n.1 Canby, William Marriott, 393 & n.1 Candolle, Augustin Pyramus de, 166 & 167 n.5, 258 & 265 n.1, 260, 284 & 295 n.9, 287 carbonate of ammonia: action on chlorophyll-bodies, 453–69; action on roots, 470–86 Cardwell, Viscount, 398 Carnarvon, earl of. See Molyneux, Henry Howard, earl of Carnarvon Carpenter, William Benjamin, Foraminifera, 334–6 & 336 n.1 Catasetum tridentatum: CD, three remarkable sexual forms, 321 & n.1 Challenger, voyage of, 408–9, 433 Chambers, Robert, 218 & 234 n.8, 337 & n.3 Chapman, Edward, 448 Charpentier, Jean de, 80 n., 141, 159 cirripedia: ‘auditory sac’, 324–6; fossils, 241; male and complemental male cirripedia, 382–5 Clarke, George, 25 & 31 n.26 Clarke, William Branwhite, 193 & n. Climbing plants, 347 n.1 Clindon, Mr., 28 Clovis (Clodowig) I, King of the Franks, 254 & n.4 coastal elevation: Chile, 32–5, 85; Pacific and Indian oceans, 37–9; subsidence in the Pacific, 437–8; volcanic phenomena and, 41–6, 70 Cobbe, Frances Power, 442 n.1, 443 n.2 Cobbold, Thomas Spencer, 386 & n.1

Index Cocos-Keeling Islands: CD’s notes on plants of, 45–6 & 46 n.1 Coddington, Henry, 235 & 236 n.2 Coe, Henry, 275 & 278 n.15, 277 Coghlan, John, 342 & 345 n.3, 344 n. Cohn, Ferdinand Julius, 417–18 & 418 n. & n.1, 453 n., 456 Colaptes campestris (pampas woodpecker), 365–6 Colenso, William, 31 n.23 Coleoptera: collected by Darwin children at Downe, 297 & nn. Cook, James, 23 & 30 n.17, 95 Cooke, Benjamin, 329 n.10 coral reefs: CD’s deductions from study of, 37–9; CD, in Manual … for H. M. Navy, 232–3; CD, query to J. L. Stokes, 191 Coral reefs, 39 n.1, 139 n.5, 165 nn.1 & 5, 23s n.; CD’s response to C. Maclaren’s review of, 162–5 corallines, 7, 8 Cordier, Pierre-Louis-Antoine, 96 n. Coste, J. J., 100 & n. & 124 n.5 Cottage Gardener and Country Gentleman, 308 n.2,310 n.2; CD, intercourse between common and Ligurian bees, 299 Cotyledon stolonifera, 419–20 Courrejolles, François Gabriel, 107 n., 110 n. cowbird. See Molothrus Crick, Francis, 487 n.2 Crick, Walter Drawbridge, 486 & 487 n.1, 487 Crocker, Charles William, 312 & n.2, 316 & nn. 1 & 2 Cross and self-fertilisation, 348 n.1, 406 n.2, 407 cross breeding: CD vindicates Gärtner’s views on, 327–8; domestic animals, CD’s questionnaire, 1839, 91–94 & 94 n.1; fertility of hybrid geese, 429–30; fowls, 308–9; horses, 311; plants, 297–8, 307–8, 309–10; strawberries, 322–3 cross-fertilisation: Papilionaceae, 350–51 Crowe, John Rice, 308 & 309 n.2 Crüger, Hermann, 329 & 330 n.2, 330 Cuming, Hugh, 196 & 203 n.6 Cumming, Joseph George, 209 & n. & 216 n.5, 210, 213 Cuvier, George, 8 & 15 n.39, 222 Cyclamen persicum: action of carbonate of ammonia on roots, 480–83 Cynocephalus: sexual selection, 400 Cynopthecus niger: sexual selection, 400 Cypripedium insigne: fertilisation of, 354–5 & 355 n.1 Cytisus scoparius: fertilisation of, 349 Dabs, William, 174 n.2 Dallas, William Sweetland, 427 & 428 n.2 Darwin Medal, Midland Union of Natural History Societies, 433 & n.1 Darwin, Anne Elizabeth, 416 n.4 DARWIN, CHARLES ROBERT Beagle voyage, arachnid collections, 348 n.1; birds of Patagonia, 426 & n.1; caribideous insect collections, 140;

Index edible fungi, 189–90; erratic boulders, 79–80, 80 & n., 147–61; fossil collections, 37 n.1; freshwater bivalves, 487; geological work on board ship, 216–34 & 234 n.1; guanaco, habit and meat of, 172–3; J. S. Henslow recommends CD to R. FitzRoy and takes charge of his specimens, 318; J. S. Henslow, recollections of, 317–19; labourers’ diet in mines of Chile, 428; letters from published by J. S. Henslow, 2–14 & 14 nn.1 & 2; marine invertebrates, 172 n., 186 n.; microscope, use on board ship, 234–40; observations of arrow worms (Sagitta), 167–71 & 172 n.1; pampas woodpecker, 365–6 & 267 n.2; plant collections, Cocos-Keeling Islands, 45–6 & 46 n.1; pocket notebooks, 219 & 234 n.10; reflected in Manual for H. M. Navy, 234 n.1; rust in wheat, 176–7 honours: Alleloplasis darwinii named for, 39; Midland Union of Natural History names Darwin Prize in his honour, 433 & n.1; New York Liberal Club, Honorary Member, 369 n.1; Netherlands Zoological Society presents photograph album to, 406–7 & 407 n.1; Oxford University, health prevents from accepting honorary degree, 365 & n.1; Yorkshire Naturalists’ Union presents address to, 434 memorials, co-signatory: Mr Ayrton and Dr Hooker, 373 & n.1; British Museum, management of, 206–8 & 208 n.1; British Museum, proposed severance of natural history collections, 269–72 & 272 n.1, 278–81 & n.1; Cambridge University, previous examination in Greek, 423 & 424 n.1; Council of the Royal Horticultural Society is asked withdrawal of prizes for collection of native plants, 346–7 & 347 nn.; fossils, recommendation that British Museum purchase, 46–7 & 47 n.1; giant tortoise of Aldabra, protection of, 394–6; National Herbaria, 386–8 & 388 n.1; Rolleston memorial fund, 448; proposed South African Confederation, 416–17; zoology of the Challenger expedition, 408–9 personal activities: avoidance of interviews, 420; E. Barbier, conversation with, 427 & n.1; C. Boner, acknowledges books sent by, 367; bucket rope for wells, 242 & n.1, 266; Down Friendly Club, Treasurer’s address, 405; Field Land Refuge, acknowledges donations to, 282; health, poor state of, 367; horse riding, 377 & n.3; printed acknowledgement of correspondence, 357 & n.1; tanks and hose, seeks advice, 243–4 & 244 n.2 prefatory notices: A. Kerner, Flowers and their unbidden guests, 420; H. Müller, Fertilisation of flowers, 490–91; W. T. Van Dyck, modification of street-dogs by sexual selection, 488–9; A. Weismann, Studies in the theory of descent, preface, 452–3 professional activities: BAAS, committee drawing up queries for travellers concerning the human race, 128 & n.; Geological Society, Secretary, 47 n.6; Royal Society, Royal Medal awarded to J. Richardson, 256–7 & 257 n.1. See also CD memorials, co-signatory, above

519 publications. See also under titles of books and journals public policy: animal experimentation, 398–9; 441–2, 442–3; animal experimentation, defence of D. Ferrier, 452 & n.1; British Museum, natural history collections, 269–72 & 272 n.1, 278–81 & n.1, 296–7 & 297 n.2, 364–5; bookselling, freedom of booksellers to settle retail price, 243; cut or uncut pages, 353–4 & 354 n.1; infant education, 439–40; Council of the Royal Horticultural Society is asked withdrawal of prizes for collection of native plants, 346–7 & 347 nn.; proposed South African Confederation, 416–17; vermin and traps, 339–40 & 340 n.2; (with R. FitzRoy) missionary activity in Tahiti and New Zealand, 15–30. See also memorials, co-signatory above reviews: H. W. Bates, Insect fauna of the Amazon valley, 330–34; G. R. Waterhouse, Natural history of the mammalia, 203–5 scientific interests: ancient gardening, sowing of runner beans, 345 & n.1; animal cross-breeding, questionnaire, 90–93 & 93 n.1; ants, perception, 381 & n.2, 381–2 & 382 n.3; bees, and fertilisation of kidney beans, 267–8; bees, intercourse between common and Ligurian, 299; bees, purportedly carnivorous, 428; bees, size in Jamaica, 320, 321; bees, whether differing in parts of Great Britain, 319–20; biographical sketch of an infant, 409–16; birds, destruction of flowers of primrose, 390–91 & 391 n.1, 391–3; birds, duration of life, 363–4 & 364 n.1; blighted wheat, 176–7; breeding of mouse-coloured ponies, 266; carbonate of ammonia, action on chlorophyll-bodies, 453–69; carbonate of ammonia, action on roots, 470–86; cherry blossom, 399–400; cirripedia, ‘auditory sac’, 324–6; cirripedia, list of for BAAS, 255–6; cirripedia, males and complemental males, 382–5; climbing plants, movements and habits, 347 & n.1; coastal elevation, Chile, 32–5; coastal elevation and subsidence, Pacific and Indian oceans, 37–9; Cocos-Keeling Island plants, 45–6 & 46 n.1; coral reefs, 37–9, 191; coral reefs, response to C. Maclaren’s review, 162–5; Cotyledon, growth indoors, 419–20; cross-bred plants, 297–8, 307–8, 309–20; cross-breeding, fowls, 308–9; crossfertilising papilionaceous flowers, 350–51; Cypripediums, fertilisation of, 354–5 & 355 n.1; Cytisus scoparius, note, 348; dimorphism in Primula, 322 & n.1; dispersal of freshwater bivalves, 486–7; double flowers, their origin, 165–6 & 166 n.1; drift deposits near Southampton, 436–7; dun horses, 306 & n.1, 308–9, 311; dust, Atlantic ocean, 191–5; edible fungi, Terra del Fuego, 189–90 & 190 n.1; elephants, reproductive power, 358 & n.1, 359 & n.3; erratic boulders, 79–80, 95–6, 128–33 & 133 n.1, 147–61, 208–15 & 215 n.1; expression of the eye, 435; expression, questionnaire, 351–2 & 353 n.1;

Index

520 DARWIN, CHARLES ROBERT (cont.) Falkland Islands, geology, 195–202; fertilisation of Fumariaceae, 389; fertilisation of plants, 406; fertilisation of winter-flowering plants, 361; fertility of hybrid geese, 429–30; fertility of organisms, 371; finches, habits of, 32; floating ice, 241; fossil deposits, La Plata, 35–7; fowls, influence of form of brain on character of, 306–7; glaciation in Caernarvonshire, 140–46 & 146 n.1; gladioli, parentage of, 315; Glen Roy roads, formation of, 50–89 & 91 n.1; hedgehogs, 355; holly berries, scarcity of, 403–4, 404; humblebees, pollination by, 134–6; humble bees, whether fertilised in the air, 316–17; hybrid dianths, 257 & 258 n.1; icebergs, power to make rectilinear grooves, 244–6; inheritance, 446–8; inherited instinct, 375; insectivorous plants, 393, 394; insects, records of captures, 1829–32, 1–2; instinct, birds, 392; instincts, origin of, 377–81; legumes, natural crossing, 256; Leschenaultia, fertilisation of, 309–10, 371–3; manures and steeping ceed, 174–5; marine shells of the Amazon, 363; Medicago lupulina, note on, 348; Megatherium, discovery of, 4; meteorites, O. Hahn’s discovery of fossil organisms in, 449; Molothrus, parasitic habits, 451; commends E. S. Morse’s work on Omori shell mounds, 432; mosquitoes, 450; CD, moths, do Tineina suck flowers?, 302–3; mould, formation of, 48–50, 124–7, 173–4, 357; F. Müller, findings of, 388–9, 418–19, 424–5 & 426 n.5, 438–9, 443–5, 450; nectarsecreting organs of plants, 250; nematodes, 386; orchid, appearance on gravel walk, 338; orchids, fertilisation of, 300–302 & 302 n.1, 305–6, 315–16, 329–30; Oxalis bowei, 349–50; pampas woodpecker (Colaptes campestris), 365–6 & 267 n.2; CD, Pampean formation, thickness of, 342–5 & 345 n.1; CD, Patagonian fossil beds, 243; Patagonian stone, as volcanic product, 188–9; peas, parentage of crosses, 321–2; penguin ducks, length of leg bones, 324; perception in lower animals, 376–7; pigeons, crosses, 308–9; pigeons, modifications, 340–41; Pinguicula, irritability of, 394; Planariae, terrestrial, 179–87 & 187 n.1; Plinian Society, papers contributed to, 364; pollen, influence on appearance of ceed, 327; potato propagation, 397 & n.1; productiveness of foreign ceeds, 268–9; Pumilio argytolepsis, achenia, 303–5; records of captured insects, 1829–32, 1–2; reversion, sheep, 434–5; Rhea spp., notes on, 31–2; Sagitta, structure and propagation of, 167–71; salt of the Rio Negro, 206; salt, action on carbonate of lime, 176; sand lizard, seeks eggs of, 249; sandstone bar at Pernambuco, 137–9; scrofula and in-breeding, 407–8; sea-water, experiments discover effect on germination of ceeds, 246 & n.1, 247–9, 253–4, 258–65; seedling fruit trees, whether true to parents, 254–5; seeds, effect of salt-water on germination of, 246 & n.1, 247–9,

253–4; seeds, vitality of underground, 251–2 & 252 n.1, 253; self-fertilisation, 361; sex ratios in domestic animals, 356; sexual colours of butterflies, 430–32; sexual selection, monkeys, 400–403; shell rain, 250–51; shells, transplantation by aquatic birds, 422–3; strawberries, cross-breeds, 322–3; teasel, contractile filaments, 417–18; termites and stingless bees of Brazil, 388–9; unisexual flowers, partial change of sex, 348–9; Usnea plicata, description of, 242; variations effected by cultivation, 323; variegated leaves, 175; vegetarian diet and capacity for labour, 428; vincas, fertilisation of, 311–12, 316, 360; volcanic phenomena and continental elevation, 40–5, 69, 86–7, 97–123 & 123 n.1; volcanic rocks, structure analogous to that of glaciers, 188; yellow rain, 338; zoological nomenclature, 162 & n.1, 269 & n.1 scientific theories: design in nature, 445–6; evolution, origins of theory of, 396; inheritance, 446–7; natural selection, anticipated by P. Matthew, 299 & n.1; natural selection, confidence in adoption of theory of, 337; natural selection, defends in Spectator, 374–5; natural selection, origins of theory of, 396; natural selection, response to C. W. Thomson; origin of species, first published reference to, 39 & n.3; origin of species, letter to Athenaeum defending, 337; pangenesis, 368–9; pangenesis, reply to F. Delpino’s criticisms, 361–3 & 363 n.1; response to [R. Owen’s] review of W. B. Carpenter’s Foraminifera, 334–6; species, sketch of work on (1839), 283 & n., 283–6; Truths for the times, qualified endorsement of, 370; variation, laws of, 312–13; defends A. R. Wallace’s interpretation of his views, 373–4 & 374 n. testimonials: E. W. Brayley, 191 & n.1; W. Boyd Dawkins, 376 & n.1; T. H. Huxley, 242 & n.1; A. White, 347–8 & 348 n.1 Darwin, Emma, 405–6 n.1, 449 n.4 Darwin, Erasmus, 427 & n.1 Darwin, Francis, 357 n.1, 405–6 n.1, 418 & 419 n.4, 434 n.1, 438, 449 n.4, 482 n.; action of carbonate of ammonia on chlorophyll-bodies, 453 & 469 n.1; Coleoptera collected at Down, 297 & n.2; contractile filaments of the teasel, 417 & n.; CD endorses paper by, 409; reads CD’s papers to Linnean Society, 453, 470 Darwin, George Howard, 359 & nn.2 & 3, 427 n.1 Darwin, Henrietta. See Litchfield, Henrietta Darwin, Horace: Coleoptera collected at Down, 297 & n.2 Darwin, Leonard: Coleoptera collected at Down, 297 & n.2 Darwin, William Erasmus, 370 n.1, 416 n.2 Daubeny, Charles Gildes Bridle, 218 & 234 n.4 Davis, Charles Oliver Bond, 25 & 31 n.26 Davis, Richard, 25 & 31 n.25 Dawkins, William Boyd, 376 & n.1 De Filippi, Filippo, 326, 326 & n.5 De la Beche, Henry Thomas, 209 & 216 n.8, 211, 218 & 234 n.3

Index Decaisne, Joseph, 254 & 255 n.3 Delbouef, Joseph Rémi Léopold, 424 & 426 n.3 Delpino, Giacomo Giuseppe Federico, 361 & n.2, 361–3 & 363 n.1 Delsarte, François, 435–6 & 436 n.2 Descent, xx, 307 n.3, 309 n.5, 367 n.2, 381 n.10, 400 & 403 nn.1 & 6, 416 n.5, 432 n.2, 488 & n. Dick, Thomas Lauder: Glen Roy roads, 50 & 91 n.2, 52, 53, 54, 56, 57, 58 n., 65 n., 69, 70, 71, 72, 81 n., 82, 84, 88 Dickens, Charles, xix Dickins, Frederick Victor, 432 & n.2 Dionaea muscipula: action of carbonate of ammonia on, 457–9, 475 Diplanaria: CD describes new genus, 185–7 Dipsacus: contractile filaments, 417–18 Disraeli, Benjamin, 282 n.1 Dixon, Edmund Saul, 429 & 430 n.6 Dolomieu, Sylvain, 99 n. Doubleday, Henry, 371 & n.2 Douglas, Charles D., 40 & 45 n.2, 98 & 124 n.3, 99, 99–100 Down Friendly Club, Treasurer’s address, 405 & n.1 Drosera: irritability of, 303; D. filiformis, 393; D. rotundifolia, action of carbonate of ammonia on, 453–5, 459–63, 469, 475 Drosophyllum lusitanicum: action of carbonate of ammonia on, 463–4, 475–6, 484 Drummond, James, 303 & 305 n.1, 310 & n.6, 372 & 373 n.2 Dugès, Antoine, 179 & 187 n.3, 180 & n., 181 Duncan, Peter Martin, 408 & 409 n.1 dun horses, parentage, 306, 308–9, 311 Dupuy, Eugène, 448 & n.6 earthquakes: Chile, 1835, 10, 40–5, 97–123 earthworms, and production of mould: 48–50, 124–7, 173–4, 357 Earthworms, 50 n., 127 n., 357–8 n.1 Edinburgh New Philosophical Journal: CD, response to C. Maclaren’s review of Coral reefs, 162–5 Egerton, Philip Grey, 270 Ehrenberg, Charles Gottfried, 243; Atlantic dust, constituents of, 191–5 & 194 n., 230 & 234 n.18; Patagonian stone, quotes CD’s description of, 188–9; Planariae, 179 & 187 n.4, 180 Ekmarck, Carl Daniel, 364 & n.3 El’leparu (York Minster), 30 n.3 elephants: reproductive power, 358 & n.1, 359 & n.3 Eliot, George, xix Eliza Scott, Antarctic voyage, 95 Elliot, W., 364 endangered species: Aldabra tortoise, 394–6; Royal Horticultural Society asked withdrawal of prizes for collection of native plants, 346–7 & 347 nn. Enderby, Charles, 95 & 96 n.1 Endlicher, Stephan Friedrich Ladislaus, 438 & 439 n.3

521 Entomologist’s weekly Intelligencer, 302 n.1; Darwin brothers, Coleoptera collected at Down, 297 & n.1; CD, do Tineina suck flowers?, 302–3 entomology: Alleloplasis darwinii, CD’s discovery of, 39; Arachnidae, CD’s descriptions of, 133–4; arachnids, Beagle voyage, 348 n.1; bees, size in Jamaica, 320, 321; bees, whether differing in parts of Great Britain, 319–20; caribideous insects collected by CD, 140; Coleoptera collected by Darwin boys at Down, 297 & n.1; coleopterous insects, CD’s collections, 128; CD queries whether Tineina suck flowers, 302–3; CD, records of captured insects, 1829–32, 1–2; CD’s review of H. W. Bates, Insect fauna of the Amazon valley, 330–34; Eripus heterogaster, CD’s description of, 134; humble bees, whether fertilised in the air, 316–17; Linyphia argyrobapta, CD’s description of, 133; Lophotus spp., CD’s discovery of, 128; mimicry, Amazon insects, 330–34; termites and stingless bees of Brazil, 388–9 Erichsen, John Eric, 398 erratic boulders, 79–80, 128–33 & 133 n.1, 147–61, 208–15 & 215 n.1, 227–8; Caernarvonshire, 144–5; distribution in South America, 128–33 & 133 n.1, 147–61 Eschwege, William Ludwig von, 158 n. Euphorbiaceae, action of carbonate of ammonia on, 470–74, 484 expression: CD’s questionnaire, 351–2 & 353 n.1 Expression, 353 n.1, 381 n.2, 436 n.3 Eyton, Thomas Campbell, 429 & 430 n.1 Falconer, Hugh, 358 & n.2 Falkland Islands: geology, 195–202 Falkner, Thomas, 25 & 31 n.24 Farrer, Thomas Henry, 418 & 419 n.3 Ferrier, David, 452 & n.1 fertilisation of flowers: CD, prefatory notice, H. Müller, Fertilisation of flowers, 490–91 The Field, the Farm, the Garden, the Country Gentleman’s Newspaper: CD, dun horses, parentage of, 306, 308–9, 311; CD, fowls, influence of form of brain on character of, 306–7 Field Lane Refuge, 282 finches, CD, remarks on habits of, 32 Fischer, Johann von, 400–401 & 403 nn.2 & 3 Fish, David Taylor, 357 & n.1, 404 & n.2 Fitch, Walter Hood, 322 n.1 Fitzinger, Leopold, 13 n. FitzRoy, Robert: Captain, H. M. S. Beagle, 15,32, 74, 97 n., 147, 318; Chilean earthquake, 40 & n., 43, 97, 113; Voyages of Adventure and Beagle, 100 n.,114 n., 158 nn.; (with CD), missionary activity Tahiti and New Zealand, 15–30 Foraminifera: CD’s response to [R. Owen’s] review of W. B. Carpenter’s work on, 334–6 Forbes, Edward, 167 & n., 214 & n., 247 & 249 n.1, 348 n.1

522 Forbes, James David, 188 & n.2, 221 & 234 n.11 Forms of flowers, 322 n.1,329 n.1, 345 n.1, 356 n.1, 356 n.1, 419 n.9 Fossil Cirripedia, 241 n. fossils: Beagle voyage, CD’s discoveries, 4, 6, 7; CD and others recommend British Museum’s purchase of, 46 & 47 n.2; CD’s advice on collection of, 220–22; Falkland Islands, footprints, 222–3; in Pampean formation, 342–5; Lepadidae, 241 & n.1; deposits in La Plata, 35–7; Patagonian fossil beds, 243 fowls: influence of form of brain on character of, 306–7; Polish, 341, 342; sexual selection, 402 Fox, Henry Stephen, 157 n. Fragia: action of carbonate of ammonia on roots, 479 Frankland, Edward, 392 & 393 n.3 Freeman, Richard Broke, xxi, xxii Froriep, Robert Friedrich, 254 & n.8 Fuegians, on Beagle voyage, 16 & 30 n.3; New Zealand missionaries’ interest in, 25–6 Fumariaceae, fertilisation, 389 fungi: collected by CD, 139; edible, of Terra del Fuego, 189–90 & 190 n.1 Galapagos islands, finches, 32; note on lichen, 242; tortoises, 396 Gallus bankiva: cross-breeding, 308–9 Galton, Francis, 368 & 369 nn.2 & 6 Gardeners’ Chronicle and Agricultural Gazette: J. Lindley, editor, 167 n.3 communications from CD: action of salt on carbonate of lime, 176; ancient gardening, 346 & n.1; appearance of an orchid in a singular place, 338; bees and fertilisation of kidney beans, 267–8; bees, and fertilisation of Papilionaceae, 272–7 & 277 n.1; breeding of mouse-coloured ponies, 266; British Museum, proposed severance of natural history collections, 278–81 & n.1; bucket rope, C242 & n.1; cross-bred plants, whether permanent, 297–8; cross-fertilising papilionaceous flowers, 350–51; double flowers, origin of, 165–6; Drosera, irritability of, 303; fertilisation of Cypripediums, 354–5 & 355 n.1; fertilisation of Leschenaultia, 371–3; fertilisation of orchids by insects, 300–302 & 302 n.1, 305–6, 315–16; fertilisation of vincas, 311–12; fertility of crossed plants, 406; growth under difficulties, 419–20 & n.1; holly berries, scarcity of, 403–3; hose between tanks, 243–4 & 244 n.2; humble-bees, pollination by, 134–6; hybrid dianths, 257 & 258 n.1; kidney beans, crossing of, 275; lizard eggs, 249; manures and steeping ceed, 174–5; natural crossing among legumes, 256 & n.2; natural selection anticipated by P. Matthew, 299 & n.1; nectar-secreting organs of plants, 250; origin of mould, 173–4, 357; Oxalis bowei, 349–50; partial change of sex in unisexual flowers, 348–9; peas, parentage of

Index crosses, 321–2; Pinguicula, irritability of, 394; productiveness of foreign ceeds, 268–9; Pumilio argytolepsis, achenia, 303–5; rust in wheat in Plata, 176–7; salt of the Rio Negro, 206; ceedling fruit trees, 254–5; ceeds, effect of salt-water on germination of, 246 & n.1, 247–9, 253–4; sex ratios in domestic animals, 356; shell rain in Isle of Wight, 250–51; variegated leaves, 175; vermin and traps, 339–40 & 340 n.2; vincas, 316 & n.2; vitality of seeds, 251–2 & 252 n.1, 254; yellow rain, 338 Gardener’s Magazine, 273 & 277 n.6 Garett, Edward Lacy, 359 & n.1 Garner, Robert, 325 & 326 n.6 Gärtner, Karl Friedrich von, 250 & n.1, 254 & n.2, 257 & 258 n.2, 275, 298 & 299 n.6, 327 & n.1, 329 n.5, 350 & 351 n.2; CD’s vindication of, 327–8 Gaudin, Charles, 201 n. Gay, Claude, 9 & 15 n.45, 100 & n. Geikie, James, 436 & 437 n.1 Geological Society: CD, Secretary, 47 n.6; H. Warburton, President, 47 n.2; Proceedings. See Proceedings of the Geological Society; Quarterly Journal. See Quarterly Journal of the Geological Society of London geology: Atlantic ocean, dust, 191–5; coastal elevation, Chile, 32–5; coastal elevation, Pacific and Indian oceans, 37–9; coral reefs, 37–9, 162–5, 191; Cordilleras, 11; CD, ‘Geology’, in Manual … for H. M. navy, 216–34 & 234 n.1; drift deposits, Southampton, 436–7 & 437 n.1; erratic boulders, 79–80, 95–6, 128–33 & 133 n.1, 147–61, 208–15 & 215 n.1; Falkland Islands, 195–202; glaciation in Caernarvonshire, 140–46; Glen Roy roads, CD’s account of, 50–89 & 91 n.1; icebergs, power to make rectilinear grooves, 244–6; mould, formation of, 48–50, 173–4, 357; Pacific subsidence, 437–8; Pampean formation, thickness of, 342–5 & 345 n.1; salt, action on carbonate of lime, 176; sandstone bar at Pernambuco, 137–9; shell rain, 250–51; volcanic phenomena, South America, 97–123 & 123 n.1; volcanic phenomena, and continental elevations, 40–5, 69; volcanic rocks, structure analogous to that of glaciers, 188 Gerstaecker, Carl Eduard Adolph, 386 n.3 Gillies, John, 101 & n. gladioli: parentage of, 315 Gladstone, William Ewart, 364, 373 & n.1, 386 Glen Roy roads, xvi, 50–89 & 91 n.1 Godron, Dominique Alexandre, 260 & n., 319 & 321 n.1 Goethe, Johann Wilhelm von, 165 n.1 Goodacre, Francis Burges, 429 & 430 n.3 Gooseberry Grower’s Register, 324 n.5 Goss, John, 329 n.9 Gould, John, 32 & nn.1 & 2, 203 Graah, Wilhelm August, 154 n. Gray, Arthur H., 423 & n.3, 486

Index Gray, Asa, 268 & 269 n.2, 329 n.1, 347 n.1, 394 n.3; CD outlines natural selection in letter to, 283 & 288 n.4, 286–8 Gray, John Edward, 128 & n.1 Groom, Henry, 175 & n.1 Groom-Napier, Charles Otley, 351 n.1 guanaco, habit and meat of, 172–3 Günther, Albert, 396 n.1 Haeckel, Ernst, 396 n.1 Hague, James Duncan, 381 & nn, 381, 382 & n.3 Hahn, Otto, discovery of fossil organisms in meteorites, 449 & n.1 Hall, Basil, 34 & 35 n.3 Hall, James, 78 n., 110 n. Hamilton, George Alexander, 269, 297 n.2 Hamilton-Gordon, Arthur Charles, 394 & 386 n.1 Harborough, Earl of. See Sherard, Robert, Earl of Harborough Hardwicke’s Science Gossip: CD, hedgehogs carrying fruit, 355 Harting, Pieter, 406 Hawkins, Thomas, 46 & 47 n.4 hedgehogs: observed carrying fruit, 355 Henry, William, 28 & 31 n.27 Henslow, George, 348, 349 & n.1, 406 & n.1 Henslow, John Stevens, xv,177; Angelsea quartz-rock, paper on, 202 n.; blighted wheat, note on, 176–7; clinometer, 218; CD’s letters from the Beagle published by, 2–14 & 14 nn.1 & 2; CD’s recollections of, 317–19; Florula keelingensis, 45–6 & 46 n.1 Herald of Health and Journal of Physical Culture: CD noted vegetarian diet of Chilean miners, 428 Herbert, William, 287 & 296 n.20, 328, 350 & 351 n.1 Herschel, John Frederick William, 87 & 91 n.18, 207; editor, Manual … for H. M. navy, 216 & 234 n.1 Hildebrand, Friedrich, 354–5 & 355 n.2 Hill, Richard, 320 & n.1 Hitchcock, Edward, 80 & 91 n.14, 208 & 215 n.2, 209 & n. Höchberg, Karl, 428 n.1 Hodgkin, Thomas, 128 & n.1 Hofacker, Johann Daniel, 308 & 309 n.3 Hoffmann, Hermann, 418 & n.2 Hogg, Robert, 308 n.2 holly berries: scarcity of, 403–4 Holmgren, Frithiof, 441 & 442 n.1, 443 n.1 Hooker, Joseph Dalton, 242, 247 & 249 n.2, 252, 253, 258, 268 & 269 n.3, 297 n.1, 371; CD’s ms. on natural selection read by (1839), 283; with C. Lyell, introduces papers by CD and A. R. Wallace on natural selection to Linnean Society, 282 & 295 n.1; CD signs memorial in support of, 373 & n.1; A. R. Wallace’s essay on natural selection read by (1858), 283 Hooker, William Jackson, 297 & n.1, 387 Hope, F. W., 2 n.1 Hopkins, William, 44 & 45 n.4, 114 & n., 116, 117, 118 & n., 120 n., 121, 208 & n., 214 & n.

523 Horsburgh, James, 96 & n., 194 & n. horses: dun, 306, 308–9, 311; instinct in, 376–7 horticulture: ancient gardening, sowing of runner beans, 346 & n.1; auriculas, variation in, 312–13; bucket rope for deep wells, 242 & n.1, 266; cross-bred plants, 307–8; germination of ceeds in a sand-pit, 177–9; gladioli, parentage of, 315; hybrid dianths, 257 & 258 n.1; manures and steeping seed, 174–5; peas, crossing of, 321–2, 327–8; potato cultivation, 421 & n.1; potato propagation, 397 & n.1; productiveness of foreign seeds, 268–9; seedling fruit trees, 254–5; strawberries, cross-breeds, 322–3; tanks and hose, 243–4 & 244 n.2; variations effected by cultivation, 323; vincas, fertilisation of tropical species, 311–12, 316 Horwood, John, 316 & n.3 Howorth, Henry Hoyle, 370 & 371 n.1 Hudson, William Henry, 365 & 367 n.1, 366 Huggins, William, 375 & n.1 humble-bees: activity of, 134–6; instincts, 378 Humboldt, Alexander, 3 & 14 n.9, 101 & n., 102 n.; earthquakes, South America, 108 & n., 111 & n., 115, 119 n.; table of volcanic phenomena in South America, 42 & 45 n.3, 104–5 & 104 n., 107, 109 Hutton, James, 87 n.; doctrine of repetition of small causes to produce great effects, 120 & 124 n.10 Hutton, Richard Holt, 398 Hutton, Thomas, 429 & 430 n.5 Huxley, Thomas Henry, 398, 433 & 434 n.3; applies for chair at University of Toronto, 242 & n.1 icebergs: power to make rectilinear grooves, 244–6. See also erratic boulders in-breeding: and scrofula, 407–8 The Index: CD, qualified endorsement of Truths for the times, 370 infant development: CD, biographical sketch of an infant, 409–16; CD’s continuing interest in, 439–40 Insectivorous plants, 394 n.2, 394 n., 453 & 469 n.1, 455 n., 470 n. instinct: birds, 392; horses, 376–7; origin of, 377–81; pigeons, 379–80 James, Robert Bastard, 192 & 195 n.4, 193 Jeffreys, John Gwyn, 497 & n.7 Jenyns, Leonard, memoir of J. S. Henslow, 317–19 & 319 n.1 Jesse, George Richard, 442 n.1 Johnson, George William, 308 n.2 Johnston, Alexander Keith, 248 & 248 n.14, 261 & 266 n.9 Johnstone, James Finlay Weir, 206 & n.4 Jones, Henry Bence, 368 & 369 n.4 Jones, W. and S., instrument makers, 84 & 91 n.15 Jordan, Claude Thomas Alexis, 254 & 255 n.1 Jouannot, François, 254 & n.3

524 Journal of Horticulture and Cottage Gardener: communications from CD: bees in Jamaica, size of, 320, 321; bees, whether differing in parts of Great Britain, 319–20; causes of variation in flowers, 312–13; crossbred plants, 307–8, 309–10; cross-breeds of strawberries, 322–3 & 323 n.3; effects of different kinds of pollen, 314–15; fertilisation of orchids, 329–30; humble bees, whether fertilised in the air, 316–17; influence of pollen on appearance of seed, 327; parentage of gladioli, 315; penguin ducks, length of leg bones, 324; variations effected by cultivation, 323; vindication of Gärtner, 327–8 Journal of researches, xx, 15 n.52, 31 n.25, 37 n.4, 80 n., 86 n., 95, 98 & n., 124 n.9, 145 n., 149 n., 155 & 157 & n., 158 n., 160, 162 n.4, 176 n.1, 179 & 187 n.2, 181, 189 n., 195 n.1, 206 & n.2, 206 n.3 Journal of Speculative Philosophy: CD, infant education, 439–40 Journal of the Linnean Society of London. Botany: papers by CD: action of carbonate of ammonia on chlorophyll-bodies, 453–69; action of carbonate of ammonia on roots of certain plants, 470–86; action of sea-water on the germination of seeds, 258–65; dimorphism in Primula, 322 & n.1; movements and habits of climbing plants, 347 & n.1; offspring of illegitimate unions of dimorphic and trimorphic plants, 356 & n.1; sexual relations of three forms of Lythrum salicaria, 345 & n.1; three sexual forms of Catasetum tridentatum, 321 & n.1; three species of Primula, 356 & n.1; two forms of Linum, 329 & n.1 notes by CD: on Cytisus scoparius for G. Henslow, 349; on Medicago lupulina for G. Henslow, 348 Journal of the proceedings of the Linnean Society of London. Zoology: CD and A. R. Wallace, papers on natural selection, 282–95 & 295 n.1 Karslake, J. B., 398 Keeling, William, 46 n.1 Kemp, William, letter to CD describing germination of ceeds in a sand-pit, 177–9 Kendall, Thomas, 24 & 31 n.23 Kent, William, 195 & 203 n.2 Kerner von Marilaun, Anton, 421 & n.2 Key, Henry Cooper, 314 & 315 n.3 King, John, 24 & 31 n.22 King, Philip Parker, 7 & 15 n.33, 130 & 133 n.3, 149 & 162 n.2, 158 & n. Kingsley, Charles, 403 & n.1 Kirke, J., 158 & n. Knight, Thomas Andrew, 275 & 278 n.12, 299 & n.4, 321 & 322 nn.1 & 2 Kölreuter, Joseph Gottlieb, 328 & 329 n.6 Kotzebue, Otto von, 21 & 30 n.16

Index Krohn, August David, 324 & 325 n.3 Kühne, Wilhelm Friedrich, 455 n. Lacerta agilis (sand lizard): CD seeks eggs of, 249 Lamarck, Jean Pierre Antoine de Monet, 8 & 15 n.38, 204, 294 & 296 n.23, 335 & 337 n.6, 337 Lamouroux, Jean Vincent Felix, 8 & 15 n.37 Land and Water: CD, feet of otter hounds, 351 & n.1 Lankester, Edwin Ray, 363 & 364 n.1 Le Couteur, John, 314 & 315 n.5 leaves, movement of, 443–5 Lecoq, Henri, 403 & 404 n.1 Leggett, William Henry, 419 & nn.7 & 8 Lepadidae, CD, paper on, 241 & n.1 Leptalis: mimicry, 330–31 Leschenaultia: fertilisation of, 309–10, 371–3 Lettington, Henry, 276 & 278 n.18, 338 & 339 n.1 Lewes, George Henry, 362 & 363 n.3 Lightbody, George, 312 & 314 n.2 Lindley, John, 167 n.3, 17, 261 & 266 n.10, 281 n.1, 303 & n.1, 315 & 316 n.1, 349, 353 Lindsay-Carnegie, William Fullerton, 126 n. Linnaeus [Carl von Linné], 8 & 15 n.40, 166, 253 & n.3; ‘natura non facit saltum’, 287–8 & 296 n.21 Linnean Society, 271; J. J. Bennett, Secretary, 283 & 295 n.7; CD and A. R. Wallace, papers on natural selection read to, xvi,282 & 295 n.1. See also Journal of the Linnean Society Linum: CD, ‘Two forms of Linum’, 329 & n.1 Litchfield, Henrietta, 377 n.3 Living Cirripedia, 15 nn.46 & 47, 325 nn., 382 & 386 nn.2 & 5 Loiseleur-Deslongchamps, Jean Louis Auguste, 260 & n., 315 n.6 London, Edinburgh and Dublin Philosophical Magazine: papers by CD: glaciation in Caernarvonshire, 140–46 & 146 n.1; power of icebergs to make rectilinear grooves, 244–6; sandstone bar at Pernambuco, 137–9 Lonsdale, William, 196 & 203 n.5 Lophotus spp., 128 Loudon, John Claudius, 353; Loudon’s Magazine, 273 & 277 n.6 Lowe, J., 319 & 320 n.3 Lozano, Pedro, 101 n. Lubbock, John, 316 n.3 Lyell, Charles, 3 & 14 n.4, 34, 64, 67, 68 n., 72 & n., 86, 120, 144 & n., 163, 165, 193, 228, 245, 287, 407 n.1; Antiquity of Man, 336 & 337 n.8; coral, conditions for formation of, 38, 39; CD’s (1844) ms. on natural selection sent to, 283; Elements of geology, 116 & n.,218; erratic boulders, 131 & 133 n.1, 151–2, 154; longevity of species, 36; Principles of geology, 76,84, 99 n., 115 & n., 212 & n., 218, 295 n.9, 336; reads

Index A. R. Wallace’s essay on natural selection, 283; with J. D. Hooker, introduces papers by CD and A. R. Wallace on natural selection to Linnean Society, 282 & 295 n.1 Lythrum salicaria: sexual relations of three forms of, 345 & n.1 Macacus: sexual selection, 400 Macarthur, William, 274 & 278 n.7 MacCulloch, James, Geological Map of Scotland, 78, 209 & 216 n.4; paper on Glen Roy roads, 50 & 91 n.3, 51, 52, 53, 59 & n., 69, 70, 71 n., 83, 88 MacDonald, James Wilson, 369 & 370 n.2 Mackenzie, George Steuart, 53 n. Mackintosh, James, 16 & 30 n.2 Maclaren, Charles, 143 & n.; CD responds to review of Coral reefs, 162–5 & 165 nn.1–4 Maclaren, Moray, 209 & n., 213 & 216 n.12 Maclean, Mr, civil engineer, 72 & 91 n.10, 84 MacLeay, William Sharp, 5 & 14 n.15 Macmillan’s Magazine, 375 MacNab, Mr: observes a rock on an iceberg, 95 Main, Edward, 28 & 31 n.27 Majendie, François, 442 & 443 n.4 Malcolm, Howard, 193 n. Malcolmson, John Grant, 67 & n. Mallet, Robert, 209 & 216 n.6, 230 & 234 n.19 Malthus, Thomas, 284 & 295–6 n.10, 285, 396 Mansell, Gideon Algernon, 46 & 47 n.3 Mansell-Moullin, C. W., 448 Marshall, William, 305 & 306 n.1 Martens, Conrad, 32 & n.4 Martin, John, 34 Martins, Charles, 145 & n., 160 n. Masters, Maxwell Tylden, 313 & 314 n.4 Mastodon, 7,35 Matthew, Patrick, 299 & n.1 McClelland, John, 101 n. Medicago spp., 348 Megatherium, 4,7, 35, 36, 342 Meldola, Raphael, 374 n. Mengozzi, Giovanni Ettore: CD letter to on design in nature, 445–6 & 446 nn. Meyen, Franz Julius Ferdinand, 192 n. Michell, John, 102 n., 107 n., 110 n., 113 & n., 113–14 microscopes: use on board ship, 234–40 Middleton, John, 20 & 30 n.12 Midland Naturalist, 433 & n.1 Midland Union of Natural History Societies: Darwin Prize, 433 & n.1 Miers, John, 111 n. Milne-Home, David, 209 & n., 213 & 216 n.12 Milton, John: Paradise Lost, 5 & 14 n.21 Mind, CD, biographical sketch of an infant, 409–16

525 Mira-Por-Vos, 193 n. missionaries: CD and R. FitzRoy defend work of, 15–30; Field Lane Refuge, CD’s support for, 282 Mivart, St George Jackson, 385 & 386 n.6 Möbius, Karl August, 413 & n. Moggridge, John Traherne, 381–2 & 382 n.2, 389 & 390 n.1 Molina, Juan Ignacio, 98 & n., 115 & n. Molothrus, parasitic habits, 451 Molyneux, Henry Howard, earl of Carnarvon, 416 & 417 n.1 Monro, Cecil James, 391 & 393 n.2 Mons, Jean Baptiste von, 254 & 255 n.2 Montagu, George, 364 & n.4 Moore, William James, 379 & 390 n.6 Moquin-Tandon, Horace Benédict, 313 & 314 n.3 Morren, Charles François Antoine, 315 & 316 n.2 Morris, John, 195 & 203 n.3, 196 Morse, Edward Sylvester, 432 & n.1 & 433 n.5 Morton, John Chalmers, 408 n.1 moths: CD asks whether Tineina suck flowers, 302–3; and fertilisation of orchids, 305 mould, formation of, 48–50, 124–7, 173–4, 357 Mudie’s Select Library, 353 & 354 n.3 Müller, Fritz: atavism, findings, 424–5 & 426 n.5; CD publishes findings of, 388–9, 418–19, 424–5 & 426 n.5, 438–9, 443–5, 450; leaves injured by free radiation, 450; movement of leaves, 443–5; movement of plants, 438–9; pollination by insects and butterflies, 418–19; termites of Brazil, 388–9 & 389 nn.1 & 2 Müller, Hermann, 389 & n.3; Fertilisation of flowers, prefatory notice by CD, 490–91 Murchison, Roderick Impey, 72 & 91 n.9, 214, 241, 296 & 297 n.2 Murphy, Joseph John, 424 & 426 n.4 Murray, Andrew, 331 & 334 n.2 Narbrough [Narborough], John, 9 & 15 n.42 Nation, William, 451 & 452 n.3 national herbaria, 386–8 & 388 n.1 Natural History Review: contributions from CD: Cirripedia, ‘auditory sac’, 324–6; review of H. W. Bates, Insect fauna of the Amazon valley, 330–34 natural selection: anticipated by P. Matthew, 299 & n.1; CD and A. R. Wallace, papers on (1858), 282–95 & 295 n.1; CD defends in letter to Spectator, 374–5; CD outlines origins of theory of, 396; CD responds to C. Wyville Thomson’s critique, 433–4 & 434 n.1 Natural selection, 256 n.1, 266 n.1, 268 n.3, 278 n.12, 296 n.21, 302 n.2, 359 n.3, 381 n.10 The Naturalist: CD, letter of thanks to deputation from Yorkshire Naturalists’ Union, 434

526 Nature, 365 n.1, 434 n.2 contributions from CD: black sheep, 434–5; contractile filaments of the teasel, 417–18; defends A. R. Wallace’s interpretation of his views, 373–4 & 374 n.; destruction of flowers of primrose by birds, 390–91 & 391 n.1, 391–3; dispersal of freshwater bivalves, 486–7; fertilisation of Fumariaceae, 389; fertilisation of Vinca by insects, 360; fertilisation of winter-flowering plants, 361; fertility of hybrid geese, 429–30; habits of ants, 381–2 & 382 n.3; inheritance, 446–8; inherited instinct, 375 & n.1; letter of thanks to Netherlands Zoological Society, 406–7 & 407 n.1; male and complemental male cirripedia, 382–5; commends E. S. Morse’s work on Omori shell mounds, 432; origin of certain instincts, 377–81; pangenesis, 368–9; parasitic habits of Molothrus, 451; perception in ants, 381 & n.2; perception in lower animals, 376–7; rats and watercasks, 426; reply to H. H. Howorth, 370–71; F. Müller’s findings on atavism, 424–5; F. Müller’s findings on leaves injured by free radiation, 450; F. Müller’s findings on movement of leaves, 443–5; F. Müller’s findings on movement of plants, 438–9; F. Müller’s researches on plants and insects of Brazil, 418–19; responds to C. Wyville Thomson on natural selection, 433–4 & 434 n.1; sexual colours of butterflies, 430–32; sexual selection in monkeys, 400–403; squirrels biting off cherry blossom, 399–400; termites and stingless bees of Brazil, 388–9; transplantation of shells, 422–3; zoology of the Challenger expedition, 408–9 Nelson, Richard John, 138–9 &139 n.6 New York Liberal Club, 369 New Zealand: missionaries, 23–30 Newall, Robert Stirling, 266 & n.1 Newcomb, H. L., 423 Newman, Henry Wenman, 316 & 317 n.1 Nicol, James, 215 & 216 n.15 Nicols, Arthur, 426 & n.1 Nordenskiöld, Nils Adolf, 488 & 490 n.1 Norgate, Francis, 487 & n.5 Norman, Ebenezer, 288 n.5 Northcote, Stafford Henry, 296, 421 Nott, Henry, 19 & 30 n.8, 20, 21 Ogle, William, 421 & n.1 Oliver, Daniel, 362 & 363 n.2 Omori shell mounds, 432 Ophrys: fertilisation by insects, 300–302, 305 Orbigny, Alcide Charles Victor Dessalines, d’, 32 n.1, 167 & n., 168, 196 & 203 n.4, 345 orchids Cypripediums, fertilisation of, 354–5 & 355 n.1; CD, three remarkable sexual forms of Catasetum tridentatum, 321 & n.1; Epipactis latifolia, appearance on CD’s gravel walk, 338; fertilisation of, 300–302, 305–6, 315–16, 329–30; Orchis, fertilisation by

Index insects, 300–302, 305; Pumilio argytolepsis, achenia, 303–5 Orchids, 306 nn.2 & 3, 321 n.1, 339 n.2; French translation, 360 & n.1 Origin, xv, xx, 295 n.1, 296 nn.11, 13, 16 & 17, 298 & 299 n.7, 309 n.5, 335 & n.3, 337 n.7, 341 & nn.5 & 12, 358 & n.1, 359 & n.3, 367 n.2, 378 & 381 n.2, 404 & n.2, 422 & 423 n.1, 429 & 430 n.1, 447 & 448 n.2, 451 & 452 n.1, 487 & n.6; CD answers criticisms of, 337; first published reference to origin of species, 39 & n.3 origin of species: CD, letter to Athenaeum defending, 337; CD, response to [R. Owen’s] review of W. B. Carpenter’s Foraminifera, 334–6 ornithology: Colaptes campestris (pampas woodpecker), 365–6; Rhea spp., CD’s notes on, 31–2; Galapagos finches, habits of, 32; Molothrus, parasitic habits, 451 Orton, James, 363 & n.1 Orundellico (‘Jemmy’ Button), 30 n.3 otter hounds, development of feet, 351 Owen, Richard, 35 & 37 n.1, 36, 204, 222, 340 & 341 n.2; CD answers criticisms of Origin, 337; CD responds to review of W. B. Carpenter’s Foraminifera, 334–6 & 336 n.1; Nesodon, paper on, 243; ‘Zoology’, in Manual … for H. M. Navy, ed. J. F. W. Herschel, 234 Oxalis spp.: action of carbonate of ammonia on roots, 478–9; O. bowei, fertilisation of, 349–50 Oxford University: CD’s health prevents from accepting honorary degree, 365 & n.1 Packard, Alpheus Spring, 428 & 429 n.1 Paget, James, 368 & 369 n.5 palaeontology. See fossils Palissy, Bernard, 174 & 175 n.2 Pallas, Pyotr Simon, 275 & 278 n.13, 306 & 307 n.2, 430 & n.8 Panizzi, Anthony, 273 n.5 Parish, Woodbine, 35–6 & 37 n.1 Parker, John William, 243 & n.1 Parrot, Georg Friedrich von, 103 n. Pasteur, Louis, 441 & 442 n.4 peas: crossing of, 327–8; parentage of crosses, 321–2 Peel, Robert, 354 Pelargonium zonale: action of carbonate of ammonia on, 466–4, 477–8 Pernambuco: sandstone bar, 137–9 Pernety, Antoine Joseph, 199 & 203 n.7 Pfeffer, Wilhelm Friedrich, 453 n., 456 & n., 485 & n. Phillips, John, 113 & n., 208 & n., 209 n., 210 Phillips, William, 83 n., 218 & 234 n.2 Philosophical Transactions of the Royal Society: CD, Glen Roy roads, formation of, 50–89 & 91 n.1; R. Owen, paper on Nesodon, 243 phrenology, 307 n.3, 381 n.9 Pictet de la Rive, François Jules, 335 & 337 n.5 Piderit, Theodor, 435–6 & 436 n.3

Index pigeons: cross-breeding, 308–9; descent, 341; sexual selection, 402; stock doves, 403; tumbling instinct, 379–80 Pinguicula vulgaris, irritability of, 394 Planariae, 4; terrestrial, 179–87 plant migration: productiveness of foreign ceeds, 268–9 Playfair, John, 87 & n., 214 Playfair, Lyon, 398 Plinian Society, 364 Plumptre, Charles John, 435–6 & 436 n.1 Poimare IV, Queen of Tahiti, 20 & 30 n.9 Polygonum: germination of ceeds found in a sand-pit, 178 Poole, Skeffington, 311 & n.2 potatoes: cultivation, 421 & n.1; propagation, 397 & n.1 Poulett-Scrope, George Julius, 86 & 91 n.16 Power of movement, 438 n.1, 444 n.1, 450 n.1, 482 n. Power, John, 424 n.1 Prestwich, Joseph, 67 n.2 Price, Astley Paston, 450 n.1 Prichard, James Cowles, 128 & n.1 Primula: CD, ‘Three species of Primula’, 356 & n.1; dimorphism, 322 & n.1; P. acaulis, action of carbonate of ammonia on roots, 479–80 Pritchard, George, 19 & 30 n.8, 21, 22 & n. Proceedings of the Geological Society, papers by CD: connection of volcanic phenomena and continental elevations 40–5, 69, 86; distribution of erratic boulders in South America, 128–33 & 133 n.1, 211; elevation and subsidence, Pacific and Indian oceans, 37–9; extinct Mammalia in the Plata, 35–7; formation of mould, 48–50; formation of mould, correction, 173–4; recent elevation of the coast of Chile, 32–5; R. I. Murchison quotes letter from CD on floating ice, 241 Proceedings of the Royal Horticultural Society: letter to the Council asking for withdrawal of prizes for collection of native plants, 346–7 & 347 nn. Proceedings of the Royal Society of Edinburgh: CD, analogy of the structure of some volcanic rocks and glaciers, 188 Proceedings of the Royal Society of London: CD announces of award of Royal Medal to J. Richardson, Proceedings of the Zoological Society: notes by CD: Galapagos finches, habits of, 32; pampas woodpecker, 365–6; nematodes, 386; Rhea spp., 31–2; preliminary notice, W. T. Van Dyck, modification of street-dogs by sexual selection, 488–9 Pumilio argytolepsis, achenia, 303–5 Quarterly Journal of Microscopical Science, CD endorses paper by F. Darwin, 409 Quarterly Journal of the Geological Society of London, contributions by CD: abstract of paper on Lepadidae, 241 & n.1; dust in the Atlantic ocean, 191–5; erratic boulders, 208–15 & 215 n.1; geology of the Falkland Islands, 195–202; thickness of the Pampean formation, 342–5 & 345 n.1 Quatrefages de Bréau, Jean Louis Armand, CD letter to, 340–41

527 Quenstedt, Friedrich August, 449 & n.3 Quetelet, Lambert Adolphe Jacques, 385 & 386 n.7 Quoy, Jean René Constant, 167 & n. Rachel, George W., 450 n.7 Ramsay, Andrew Crombie, 245 n.1 Reeds, Trenham, 206 & n.3 Reichenau, Wilhelm von, 488 n. Rengger, Johann Rudolf, 489 n. reversion: F. Müller’s findings, 424–5 Rhea spp., 31–2; nesting habits, 451 Rice, Thomas Spring, 46 & 47 n.1 Richardson, John, 145 n., 196 & 203 n.7; Royal Medal awarded to, 256–7 & 257 n.1 Richter, H. E., 449 & 450 n.6 Rivers, Thomas, 254 & 255 n.4 Roebuck, William Denison, 434 & n.1 Rogers, Henry Darwin, 139 & n.7, 213 & n. Rolleston, George: memorial fund, 448 & n.1 Roma Etrusca: CD, letter to G. E. Mengozzi on design in nature, 445–6 Romanes, John, 424 & 426 n.1 Ross, John Clunies, 46 n.1 Roussin, Albert Réné, 193 & n., 138 & 139 n.2 Royal Botanic Gardens, Kew: national herbaria, 387–8 & 388 n.1 Royal Commission on animal experimentation, 398–9, 441 & 442 n.3 Royal Horticultural Society: Council requested to withdraw prizes for collection of native plants, 346–7 & 347 nn. Royle, John Forbes, 303 & nn.3 & 4 Russell, Lord John, 206 Sabine, Edward, 381 n.8 Sachs, Ferdinand von, 455 n., 485 n. Sagitta, structure and propagation of, 167–71 Saint-Hilaire, Étienne Geoffroy de, 337 & n.2 Salisbury, Richard Anthony, 323 & 324 n.6 salt, of Rio Negro, 206 Sanderson, John, Sr, 434–5 & 435 n.1 Sarcey, Francisque, 427 & n.1 Sarracenia purpurea: action of carbonate of ammonia on, 464–5, 475–6 Savigny, Marie-Jules-César Lelorgne de, 8 & 15 n.41 Saxufraga umbrosa: action of carbonate of ammonia on roots, 475 Scalpellum vulgare: males and complemental males, 382–5 Scherzer, Karl von, 353 n.1 Schmidt, O., 396 & n.1 Schrenk, Leopold, 429 & n. Schulte, Eduard, 430 & 432 n.1 Schweitzer, Edward G., 258 & 265 n. Science: CD’s response to O. Hahn’s discovery of fossil organisms in meteorites, 449

528 Scientific Opinion: CD replies to F. Delpino’s criticisms of pangenesis, 361–3 & 363 n.1 Sclater, Philip Lutley, 364 & 365 n.2 Scoresby, William, 75 n. Scott, John, 330 & n.3 sea-water: CD experiments to discover effect on germination of ceeds, 246 & n.1, 247–9, 253–4, 2578–65 Sedgwick, Adam, 198–8, 376 n.1 seeds: foreign, productiveness of, 268–9; salt-water, effect on germination, 246 & n.1, 247–9, 253–4, 258–65; vitality of underground, 251–2 & 252 n.1, 254 Sefström, Nils Gabriel, 80 & 91 n.13 Semper, Karl Gottfried, 437 & 438 n.1 Seward, Anna, 427 & 428 n.3 sexual selection: butterflies, 430–32; modification of race of street-dogs, 488–9; monkeys, 400–403 Sharpe, Daniel, 195 & 203 n.3, 224 & 234 n.14 shell rain, Isle of Wight, 250–51 shells: transplantation by aquatic birds, 422–3 Sherard, Robert, Earl of Harborough, 298 & 299 n.4 Sloane, Hans, 207, 270 & 272 n.2 Smirke, Robert, 270 & 272 n.4 Smith and Beck’s, 236 n. Smith, Frederick, 320 & 321 n.3 Smith, James, 66 & 91 n.7, 72 & n., 73 n. Smith, William, 324 n.7 Solanum: action of carbonate of ammonia on roots of, 479 Sorby, Henry Clifton, 473 n. Sorrell, Thomas, 95 & 96 n.5 Sourdeaux, Adolfo, 342 & 345 n.2 South African Christian Recorder: R. FitzRoy and CD, remarks on moral state of Tahiti and New Zealand, South America, 214 & 216 n.14, 234 n.15 Southey, Robert, 17–18 & 30 n.5 Sowerby, George Brettingham, 195 & n. Spalding, Douglas Alexander, 375 & 376 n.2, 392 & 393 n.5 Spectator: CD, natural selection, 374–5 Spirogyra: action of carbonate of ammonia on, 467–8 Spix, Johann Baptist von, 13 n. Sprengel, Christian Konrad, 136 & 137 n.10 squirrels: biting off cherry blossom, 399–400 Stahl, Ernst, 456 n. Stephens, James Francis: Chiasognarthus grantii, 9 & 15 n.44; Illustrations of British entomology, 1 & 2 n.1 Stokes, J. L.: Discoveries in Australia, query by CD, 191 Stokes, John Lort, 188 & n.1 Story-Maskelyne, Thereza Mary, 393 n.4 Strickland Code, CD, co-signatory, 162 & n.1 Strickland, Hugh Edwin, 162 n.1, 269 Strong, Edward, 340 & n.1 Strzelecki, Paul Edmund de, 195 n., 196 n. Sulivan, Bartholemew James, 195 & 203 n.1, 197 & n., 198, 202 Swainson, William, 256 & 257 n.3

Index Swale, William, 274 & 278 n.8 Swayne, George, 256 & 268 n.1 Swinhoe, Robert, 353 n.1, 355 Syme, Patrick, 181 n., 190 n.2 Tahiti: missionary activity, 18–23 Taine, Hippolyte, 409 & 416 n.1, 413 Talbot, Emily, 439–40 & 440 n.1 tanks and hose: CD seeks advice, 243–4 & 244 n.2 Tawell, Samuel, 282 n.1 Taylor, Richard, 128 & n.1 teasel: contractile filaments, 417–18 Tegetmeier, William Bernhard, 306 & 307 n.1 Thomas, A. P., 448 Thompson, D’Arcy W., 490 Thomson, Charles Wyville, 382 & 386 n.1, 408–9; CD responds to criticisms of natural selection, 433–4 & 434 n.1 Thomson, William, 449 & 450 n.6 Tieghem, Philippe Édouard Léon van, 455 n. The Times, 354 n.1, 424 n.1; announces that CD’s health prevents him from accepting honorary degree at Oxford, 365 & n.1; CD acknowledges donations to Field Land Refuge, 282; CD, letters on vivisection, 441–2, 442–3; CD’s views on mosquitoes, 450; Rolleston memorial, CD joins appeal for, 448 Tineina: whether they suck flowers, 302–3 Torbitt, James, 397 & nn., 421 & n.1 Toxodon, 35 Transactions of the Botanical Society of Edinburgh: CD’s contributions to Plinian Society, 364 Transactions of the Entomological Society of London: Alleloplasis darwinii named for CD, 39 Transactions of the Geological Society: contributions from CD: distribution of erratic boulders in South America, 133 n.1, 147–61, 246 n. formation of mould, 124–7 volcanic phenomena in South America, 97–123 & 123 n.1 Transactions of the Linnean Society of London: M. J. Berkeley, CD’s notes on edible fungi of Terra del Fuego, 189–90 & 190 n.1 Transactions of the Royal Society of Arts and Sciences of Mauritius: memorial seeking protection of giant tortoise of Aldabra, 394–6 Treat, Mary, 393 & 394 n.2 Trimen, Roland, 348 n.1 Trimmer, Joshua, 143 & n., 213 & 216 n.13 Tuckey, James Hingston, 194 n. Turnbull, George Henry, 316 & n.3 Turnbull, John, 23 & 30 n.18 Turner, Sharon, 193 n. Ulloa, Antonio de, 102 n. 108 n., 109, 110 University College, London, CD’s testimonial for E. W. Brayley, 191 & n.1

Index University of Toronto, T. H. Huxley applies for chair at, 242 & n.1 Urtica, action of carbonate of ammonia on, 475 Usnea plicata, CD’s description of, 242 Vallemont, Pierre Le Lorrain, 174 & 175 n.1 Van Dyck, W. T., modification of street-dogs by sexual selection, 488–9 Variation, 94 n.1, 306 n.1, 309 n.5, 311 n.2, 315 n.6, 322 n.2, 323 & n.2, 327 n.2, 341 nn. 3, 5, 6 & 7, 346 n.1, 351 n.1, 368 & 369 nn.3 & 5, 371, 374, 380, 383, 402 & 403 n.4, 433, 445–6 & 446 nn.1 & 4, 489 Vega, voyage of, 498 & n. vegetarianism, 428 Venetz, Ignaz, 80 n., 159 vincas, fertilisation of, 316, 360 Vines, Sydney Howard, 472 & 486 n.2 Virchow, Rudolf Carl, 441 & 442 n.5 vivisection, 441–2, 442–3 Vivisection Act, 452 n.1 Volcanic islands, 176 n.2, 188 n., 196 n. volcanoes, 229–30; CD, volcanic phenomena in South America, 97–123 & 123 n.1; CD, volcanic phenomena and continental elevation, 40–5 W. B. N., ‘Native Patagonian salt’, 206 Wallace, Alfred Russel, 337; animals’ sense of smell, 376–7 & 377 n.1; CD defends interpretation of his views by, 373–4 & 374 n.; natural selection, extracts read to Linnean Society, xvi, 282, 283, 288–95 & 295 nn.1 & 6 Wallis, Samuel, 18 & 30 n.7 Walton, William, 172 & 173 n. Warburton, Henry, 46 & 47 n.3 Waterhouse, George Robert, 39, 128, 140; Natural history of the mammalia, CD reviews, 203–5 & 205 n.1 Way, Albert, 88 & 91 n.19 Webb, Edward Brainerd, 342 & 345 n.4 Wedgwood, Elizabeth, 174 n.2 Wedgwood, Josiah, II, xv, 48 & 50 n.1, 49, 124 & 127 n.5, 125, 126

529 Weissmann, August Friedrich Leopold, Studies in the theory of descent, 452–3 & 453 n.1 Wells, Joseph, 323 & 324 n.7 Welsh, Thomas, 177 Western, Charles Callis, 285 & 296 n.15 Westwood, John Obadiah, 297–8 & 298 nn.1 & 2, 299 n.9 White, Adam, 133; CD’s testimonial for, 347–8 & 348 n.1 Wickham, John Clement, 426 & n.2 Wiegmann, Arend Friedrich, 275 & 278 n.16, 328 & 329 n.8 Willdenow, Karl Ludwig, 313 & 314 n.5 Williams, Henry, 23 & 30 n.21 Williams, John, 322 & 323 n.1 Williams, William, 25 & 31 nn.23 & 26, 26 Willughby, Francis, 379 & 390 n.7 Wilson, Charles, 19 & 30 n.10, 22 Wimmarleigh, Lord, 398 Winchester, C., 250 & 251 nn.1 & 3 Wiseman, Nicholas, 128 & n.1 Woodbury, Thomas White, 299 nn.1 & 4, 319 & 320 n.4 Wrangel, Ferdinand Petrovich, 131 & 133 n.4, 152 & n., 380 Yarrell, William, 128 & n.1 Yates, Edmund Hodgson, 420 Yates, James, 128 & n.1 Yokcushlu (Fuegia Basket), 30 n.3 Yorkshire Naturalists’ Union: CD receives deputation from, 434 Zoological Society, 203, 271 Zoologist: CD and A. R. Wallace, papers on natural selection, 295 n.1 zoology: Cirripedia, ‘auditory sac’, 324–6; cirripedia, CD’s list of, 255–6; CD’s review of G. R. Waterhouse, Natural history of the mammalia, 203–5; Planariae, terrestrial, 179–87 & 187 n.1; Sagitta, structure and propagation of, 167–71 & 172 n.1; Strickland Code, 162 & n.1, 269 & n.1 zoophites, 5, 8