The high opinion Captain Fitzroy formed of Darwin during this long voyage is shown by many passages in his own narrative, and by many other references. He paid him the marked compliment of naming no fewer than three important geographical localities after him, namely, Mount Darwin and Darwin Sound (Tierra del Fuego), and Port Darwin in North Australia, thus connecting his name for future generations with two lands whose inhabitants were subjects of Darwin’s unceasing interest and investigation throughout life, and served in no small degree to elucidate the history and rise of mankind in Darwin’s mind and for a world’s instruction. Fitzroy complimented his friend markedly when himself receiving the medal of the Royal Geographical Society; and in one of his papers, speaking of him as a zealousvolunteer in the cause of science, observed that his perseverance might be estimated from the fact that he never ceased to be a martyr to sea-sickness; while his interest in science and his public spirit were evident from his having presented his valuable collections to the public.
The concluding pages of the Journal are both eloquent and instructive. Everywhere there had been fascinating visions, and attractive problems remained unsolved. Was it not significant of future studies that the contrast between barbarian and civilised man should have been so impressed upon the future author of “The Descent of Man”? He writes thus on this subject, “Of individual objects, perhaps no one is more certain to create astonishment than the first sight in his native haunt of a real barbarian, of man in his lowest and most savage state. One’s mind hurries back over past centuries, and then asks, could our progenitors have been such as these? Men, whose very signs and expressions are less intelligible to us than those of the domesticated animals; men, who do not possess the instinct of those animals, nor yet appear to boast of human reason, or at least of arts consequent on that reason. I do not believe it is possible to describe or paint the difference between savage and civilised man. It is the difference between a wild and tame animal: and part of the interest in beholding a savage, is the same which would lead every one to desire to see the lion in his desert, the tiger tearing his prey in the jungle, the rhinoceros on the wide plain, or the hippopotamus wallowing in the mud of some African river.”
We have dwelt thus at length upon the history of thiseventful voyage, not only because it filled an important space in Darwin’s life, but also because it undoubtedly gave rise to the thoughts and speculations which impelled him to devote his life to the study of problems of evolution. It has been shown to some extent, how he saw, without pre-arrangement, just those phenomena which could stimulate his mind, already fit, to its highest flights. We have seen, too, how universal was Darwin’s interest in nature, and how sympathetic a heart went with his scientific insight. He had yet to show how masterly was his patience, to work for yet twenty years, in order that he might not by premature publication of a crude theory risk defeat and throw science backward rather than forward. This long patient work was to be the triumph of his genius.
ON his return home, Darwin speedily placed himself in communication with the leaders of scientific progress, and, in consequence of the valuable results of his voyage, he soon found himself in a most advantageous position. On November 20, 1836, he was elected a Fellow of the Geological Society, and before the end of the year he had sent the manuscript of one of his early papers to Lyell, who writes to him (December 26, 1836): “I have read your paper with the greatest pleasure.... What a splendid field you have to write upon.” He strongly advised the young man not to accept any official scientific place, but to devote himself to his own line of work. But Darwin was overpersuaded, and became a member of the Council of the Geological Society in the following February, and secretary in February, 1838. This office he held with success for three years. Lyell referred in considerable detail to the young traveller’s views in his presidential address to the Society in 1837.
Darwin’s geological papers soon became numerous. In 1837 he discussed in succession the recent elevationof the coast of Chili, the deposits containing extinct mammalia in the neighbourhood of the Plata, the areas of elevation and subsidence in the Pacific and Indian Oceans, as deduced from the study of coral formations, and the formation of mould (the precursor of a work he issued more than forty years later). Papers on the connection of certain volcanic phenomena, and on the formation of mountain chains, and other geological notes on South America, were read in 1838; the interesting Parallel Roads of Glen Roy, in Scotland, which he believed to be of marine origin, were described in 1839; the erratic (glacial) boulders of South America, in 1841; and coral reefs in 1842: a full record, one would imagine, of busy years, occupied also with secretarial work. Lyell, writing to Sir John Herschel (May 24, 1837), says: “I am very full of Darwin’s new theory of coral islands, and have urged Whewell to make him read it at our next meeting. I must give up my volcanic crater theory for ever, though it costs me a pang at first.” In March, 1838, Lyell describes the reception of the paper on volcanic phenomena at the Geological Society. “He opened upon De la Beche, Phillips, and others, his whole battery of the earthquakes and volcanoes of the Andes; and argued that spaces of a thousand miles long were simultaneously subject to earthquakes and volcanic eruptions, and that the elevation of the Pampas, Patagonia, &c., all depended upon a common cause.” In fit acknowledgment of such services to science, he was elected a Fellow of the Royal Society on January 24, 1839.
Early in 1839 Darwin married his cousin, EmmaWedgwood, daughter of his uncle Josiah Wedgwood: a union which, though consanguineous, proved in the highest degree congenial and fortunate. In succeeding years a numerous family of sons and daughters surrounded the happy parents. After considerable delays by the Admiralty, though it had long been ready, the Journal appeared, in 1839, as the third volume of Fitzroy’s “Voyages ofThe AdventureandBeagle.”The Quarterly Review(lxv. 224) said that there could be no two opinions of its merits. “We find ample materials for deep thinking; we have the vivid description that fills the mind’s eye with brighter pictures than painter can present, and the charm arising from the freshness of heart which is thrown over these virgin pages of a strong intellectual man, and an acute and deep observer.” Its merits, however, were somewhat slow to become known to the general public, owing to the original expensive form of publication; and it was not till 1845, when the second and enlarged edition appeared as “The Journal of Researches,” that the popular ear was gained. Later, under the title, “A Naturalist’s Voyage Round the World,” the book has become very widely known and appreciated.
The publication of “The Zoology of the Voyage ofThe Beagle,” commenced in 1838, under Darwin’s superintendence, gave a fuller view of the acquisitions to natural history which had been made than had previously been possible. The Treasury, acting on the representations of the presidents of the Linnean, Zoological, and Geological Societies, as well as of the naturalist himself, in 1837 made a grant of £1000 towards the expenses of publication of these memoirs. Owen’s description of thefossil mammalia, completed in 1840; G. Waterhouse’s of the living mammalia, in 1839; Gould’s of the birds, in 1841; L. Jenyns’s of the fish, in 1842; and Thomas Bell’s of the reptiles, in 1843—all in quarto, with beautiful plates, were a solid testimony to a splendid success. Darwin furnished an introduction to each part, and the portions of the text referring to the habits and ranges of the living animals. Three species of mastodon and the gigantic megatherium were the only extinct mammalia known from South America previous to Darwin’s voyage. To these were now added theMylodon Darwinii, a giant sloth; the scelidotherium, a somewhat smaller form; the great camel-like, yet odd-toed, macrauchenia; and the toxodon, as large as a hippopotamus, yet having a strange resemblance to the little rodents. All these belonged to geological deposits not far anterior to the present age. The collections of living vertebrates were less profoundly interesting, but the number of new species was large; and the habits and localities being recorded by so good an observer, gave them additional value.
The fossil mammals were given by the generous traveller to the London College of Surgeons, the mammals and birds to the Zoological Society, the reptiles to the British Museum, and the fishes to the Cambridge Philosophical Society. Nor was this all. The collections of insects, shells, and crustacea were described by many able specialists in scientific publications. The flowering plants were described by Hooker, and the non-flowering by Berkeley; and, altogether, no expedition ever yielded a more solid result to the scientific naturalist, while furnishinga delightful narrative to the general reader, and laying the foundation for generalisations of surpassing importance to all thinking minds.
It was evident to many geologists that the greatest value would attach to the full record of the geological observations made by the gifted young secretary of the Geological Society. A year after the publication of the Journal the first portion of these observations, dealing with coral reefs, was almost ready, but the continued ill-health of the author delayed the publication till 1842. When it appeared, under the title of “The Structure and Distribution of Coral Reefs,” its success was immediate and complete.
Ever since their first description by voyagers, marvel had been expressed at the strange and beautiful phenomena presented by coral islands. Coral, as being built up by the tireless labours of innumerable so-called “insects,” or “worms,” had become associated with romantic ideas. It really consists of the internal skeletons of coral-polyps, allied to the sea anemone. Captain Basil Hall, in his “Voyage to Loo Choo,” looking with the eyes of one ignorant of zoology, had credited the building of coral reefs to all kinds of creatures which lived on and near the coral after it had been made; and his erroneous views had been amplified and developed by James Montgomery, in his “Pelican Island,” into the most fantastically incorrect description that ever versifier penned. Sad to relate, his lines were often quoted, as if correct, by scientific men in pre-Darwinian times.
Nothing gives clearer evidence of the power of mind which Darwin had already attained when voyaging roundthe world than the originality of his views on coral reefs. The lagoon islands, or atolls, he describes as “vast rings of coral rock, often many leagues in diameter, here and there surmounted by a low verdant island, with dazzling white shores, bathed on the outside by the foaming breakers of the ocean; and, on the inside, surrounding a calm expanse of water which, from reflection, is of a bright, but pale, green colour.” Keeling atoll, outside which, at less than a mile and a half distance, no bottom was found with a line 7,200 feet in length, having been fully described, and an account given of all other known atoll systems, the peculiarities of the great barrier reef of North-east Australia, and that of New Caledonia, were recounted. Off the latter, no bottom was found, at two ships’ length from the reef, with a line 900 feet long. With these were linked the smaller reefs of Tahiti and others, where considerable islands are more or less completely surrounded by them. Next, the fringing or shore reefs, at first sight only a variety of barrier reefs, were clearly distinguished from them by the absence of an interior deep-water channel, and their not growing up from an immense, but from a moderate depth of water.
The remarkable fact was pointed out by Darwin that all coral islands are within a little more than 30 degrees of the Equator, but that, at the same time, they are absent over certain larger areas within the tropical seas. There are none on the West Coast of South America, nor on the West Coast of Africa. In this portion of his work we have another significant sentence bearing on the struggle for existence. In discussing the apparently capriciousdistribution of coral reefs, he remarks that “the study of the terrestrial and better-known half of the world must convince every one that no station capable of supporting life is lost—nay more, that there is a struggle for each station between the different orders of nature.” He describes the large fishes and the trepangs (holothuriæ) preying upon the coral-polyps, and shows how complex are the conditions which determine the formation of reefs on any shore. Perhaps no part of his work is more important than that in which he collects the evidence proving how rapidly coral masses grow, and that they for the most part cannot flourish in a greater depth of water than fifteen fathoms.
Reasoning upon the facts observed by himself and others Darwin now proceeded to upset the received theory that atolls were based upon submarine volcanic craters, and to substitute for it the view that there has been a prolonged and gradual subsidence of the areas upon which the atolls are based, and a corresponding upward growth of the reef-building corals. Thus fringing-reefs in time become barrier-reefs; and barrier-reefs, when they encircle islands, are converted into atolls, or lagoon islands, as soon as the last pinnacle of land sinks beneath the surface of the ocean. The whole matter is summed up thus: “A magnificent and harmonious picture of the movements which the crust of the earth has within a late period undergone is presented to us. We see vast areas rising, with volcanic matter every now and then bursting forth through the vents or fissures with which they are traversed. We see other wide spaces slowly sinking without any volcanic outbursts; and we may feel sure that this sinking musthave been immense in amount as well as in area, thus to have buried over the broad face of the ocean every one of these mountains above which atolls now stand like monuments, marking the place of their former existence.” “No more admirable example of scientific method was ever given to the world,” says Professor A. Geikie, “and even if he had written nothing else, this treatise alone would have placed Darwin in the very front of investigators of nature.”
After thirty-two years’ interval, a second edition of “Coral Reefs” appeared, in a cheaper form, in 1874. It is rare indeed for a scientific treatise to attain at once and maintain so long a position of such undisputed authority. The eminent German naturalist, Semper, in 1863, criticised the general theory in consequence of his own careful examination of the Pelew Islands; but Darwin easily answered him by pointing to the cumulative evidence in favour of his own views. The only really important work on the subject, after Darwin’s, was that of Professor J. D. Dana, the eminent American naturalist and geologist, on “Corals and Coral Islands,” published in 1872. Darwin, in the preface to his second edition, candidly acknowledged that he had not previously laid sufficient weight on the mean temperature of the sea in determining the distribution of coral reefs; but this did not touch his main conception. In fact, he maintained his ground undisturbed, and at the same time admired greatly Dana’s book, which was the result of personal examination of more coral formations than perhaps any one man had ever studied, and which accepted Darwin’s fundamental proposition, that lagoon islands or atollsand barrier-reefs have been formed during periods of subsidence.5
No such strikingly original theory is propounded in the second part of “The Geology of theBeagle” dealing chiefly with volcanic islands. St. Jago, in the Cape de Verde Islands; Fernando Noronha, Terceira, Tahiti, Mauritius, St. Paul’s, Ascension, St. Helena, and the Galapagos are in turn more or less fully described, according to the opportunities the explorer had possessed. To some extent, as in the succeeding part, Darwin adapts his views on mountain elevation too closely to those enunciated by Elie de Beaumont. The third part of the geology of theBeagle, entitled “Geological Observations on South America,” was not published till 1846. Even this did not exhaust the contributions to geology made from theBeaglevoyage, for it did not include the papers on the “Connection of certain Volcanic Phenomena in South America” (1838); on the “Distribution of Erratic Boulders” (1841); on the “Fine Dust which falls onVessels” (1845); and on the “Geology of the Falkland Islands” (1846). A second edition of the two latter parts of “The Geology of theBeagle” was published in one volume in 1876.
Meanwhile, after spending a few years of his early married life in London, during which he was often in ill-health, Darwin fixed his residence in 1842 at Down House, near Beckenham, Kent. The little village of Down, three or four miles from the Orpington railway station, was near enough to London for convenient access, yet greatly secluded and thoroughly rural. The traveller’s roving days were over, and his infirmity of health prevented him from undertaking very fatiguing journeys. After the cessation of his active work for the Geological Society, Darwin’s chief public appearance was when he spoke at the Oxford meeting of the British Association, in 1847, when, strange to say, Ruskin was secretary of the Geological Section.
At Down then, situated some 400 feet above the sea level on a plateau of chalk, interrupted by wavy hollows with beech woods on the slopes, about forty years of Darwin’s life were passed. Down House, one of the square red brick mansions of the last century, to which have been since added a gable-fronted wing on one side and a more squarely-built wing and pillared portico on the other, is shut in and almost hidden from the roadway by a high wall and belt of trees. On the south side a walled garden opens into a quiet meadow, bounded by underwood, through which is seen a delightful view of the narrow valley beyond, towards Westerham.
One of the most admirable chapters of the well-known“Manual of Scientific Enquiry,” published in 1849, for the use of the navy and travellers generally, and edited by Sir John Herschel, was Darwin’s, on Geology. The explorer is here taught to make the most of his opportunities upon the soundest principles. The habits which the author had himself formed are inculcated upon the observer—copious collecting, accurate recording, much thinking. Nothing is omitted. Number-labels which can be read upside down must have a stop to indicate the right way up; every specimen should be ticketed on the day of collection; diagrams of all kinds should be made, as nearly as possible, to scale. “Acquire the habit of always seeking an explanation of every geological point met with.” “No one can 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.” Truly an ample reward awaited the observer who could thus speak of the value of “a ray of light;” he certainly did, to use the concluding words of the essay, “enjoy the high satisfaction of contributing to the perfection of the history of this wonderful world.”
Meanwhile Darwin had been carrying on a great research on the very peculiar order of crustacea, termed Cirripedia, better known as barnacles and acorn shells. He had originally only intended to describe a single abnormal member of the group, from South America, but was led, for the sake of comparison, to examine the internal parts of as many as possible. The British Museum collection was freely opened to him, and as the importance of studying the anatomy of manyspecimens became evident, the splendid collections of Messrs. Stutchbury, Cuming, and others were placed at his disposal, and he was permitted to open and to dissect unique specimens of great value. In fact, almost every naturalist of note who had any knowledge of the subject freely aided him, and the result was a masterly series of finely illustrated volumes; two on the living Cirripedia, issued by the Ray Society in 1851 and 1854; and two on the fossil Cirripedia of Great Britain, by the Palæontographical Society, published in the same years. There is evidence in these volumes that careful observations on the growth of these creatures had been made as far back as the visit to the Galapagos Islands in 1835. In many respects these works are as masterly as any the author ever wrote. Considering the previous obscurity of the subject, the difficulties attending the research, the almost entire lack at that time of any general microscopical knowledge of tissues, and especially of those of embryos, Darwin’s success is marvellous. The details are too technical for statement here, but any one with a zoological training, who studies the strange complication of the reproductive systems, and the remarkable transformations which the young undergo, as told in these volumes, will appreciate more than ever the breadth and the solidity of the basis of patiently acquired knowledge which Charles Darwin had accumulated while his “Origin of Species” was taking shape.
At the anniversary meeting of the Royal Society in November, 1853, a royal medal was presented to the author of “Coral Reefs” and the “Memoir on the Cirripedia,” the president, the Earl of Rosse, eulogizingthe former as one of the most important contributions to modern geology, and the latter as containing new facts and conclusions of first-rate interest. Finally, this chapter of Darwin’s life may be closed with the tardy award of the Wollaston medal to him by the Geological Society, in February, 1859, when Professor John Phillips spoke of him as combining the rarest acquirements as a naturalist, with the qualifications of a first-class geologist, and as having by his admirable monograph on the fossil Cirripedia added much to a reputation already raised to the highest rank.
Yet even such a reputation could not secure fair treatment and impartial judgment for the coming book, the subject of which might be supposed to require supreme gifts of the very kind Darwin possessed.
IF no other record of Darwin’s twenty-two years (1837-59) of life and thought after his return to England remained than the papers and books he published during that period, we should find enough to place him on a level with the most gifted biologists and geologists of his age. But all that time he was occupied with thoughts, researches, and experiments, of which the world at large perceived no fruits. Few persons suspected that a tremendous revolution in scientific thought was in preparation at the quiet country home at Down. New species of animals and plants were being described by naturalists at an alarming rate. The bulk of knowledge of specific characters and the necessity of specialisation bade fair to make every species-monger a dry and narrow pedant; and the pedants quarrelled about the characters and limits of their species.
In the later years of this period some rays of improvement shone out. To end the reign of Owen’s misleading types and imaginary archetypes, there arose a wielder of two potent words, “morphology” and “biology,” the sciences of form and of life, who showed that differences of adult form grew out of likeness and simplicity in theyoung; and that the life of plants and animals was one science, their study one discipline. What Huxley had begun to proclaim from the housetop, Darwin was meditating in secret; and much more. Let us see how he states the case in the famous modest opening of the “Origin of Species” (1859): “When on board H.M.S.Beagle, as naturalist, I was much struck with certain facts in the distribution of the inhabitants of South America, and in the geological relations of the present to the past inhabitants of that continent. These facts seemed to me to throw some light on the origin of species—that mystery of mysteries, as it has been called by one of our greatest philosophers. On my return home, it occurred to me, in 1837, that something might perhaps be made out on this question by patiently accumulating and reflecting on all sorts of facts which could possibly have any bearing on it. After five years’ work I allowed myself to speculate on the subject, and drew up some short notes; these I enlarged in 1844 into a sketch of the conclusions, which then seemed to me probable: from that period to the present day I have steadily pursued the same object. I hope that I may be excused for entering on these personal details, as I give them to show that I have not been hasty in coming to a decision.” We learn also, independently, from the “Expression of the Emotions” (p. 19), that Darwin as early as 1838 was inclined to believe in the principle of evolution, or the derivation of species from other and lower forms.
It is somewhat difficult to decide precisely what Darwin owed to his predecessors who believed in the mutability of species and doubted their separate creation;this is partly owing to his exceeding modesty. He was over-ready to acknowledge the value to himself of other people’s ideas, and he under-estimated the strength of the illumination which his own mind threw upon those ideas, transforming them from guesses into probable hypotheses, confirming them by his vast and varied knowledge, and building a superstructure where they had laid but an uncertain foundation. The question was in the air; guessing replies of great interest were made by a few who doubted the received belief; but they were not satisfying answers and they did not effect a revolution. Goethe in Germany, Erasmus Darwin in England,6andGeoffroy Saint Hilaire in France, came independently to similar conclusions as to the mutability of species; and Lamarck followed with several well-known works in 1801-15, in which he upholds the doctrine that all species, including man, are descended from other species. As Darwin says, Lamarck first did the eminent service of arousing attention to the probability of all change in the organic, as well as in the inorganic world, being the result of law, and not of miraculous interposition. He saw the difficulty of distinguishing between species and varieties, the almost perfect gradation of form in some groups, and the great similarity of domestic breeds of animals to such species. He believed that some degree of change was produced by the physical conditions of life, the intercrossing of species, and by habits causing increased use or disuse of parts. Indeed he thought very many remarkable adaptations, such as that of the neck of the giraffe for browsing on trees, were the effect of habit. But he attributed, perhaps, more to a law of progressive development impressed on all forms of life,which thus would all in time gradually cease to be lowly, their place being taken by new forms continually or “spontaneously” generated.
It does not appear that Lamarck would by any means have sufficed to convince Darwin, judging from his references to him in his Journal and the “Origin.” Here is the passage in which in the second edition of his Journal he refers to the blindness of the Brazilian Tucutuco, or Ctenomys, a rodent or gnawing mammal with the habits of a mole: “Considering the strictly subterranean habits of the Tucutuco, the blindness, though so common, cannot be a very serious evil; yet it appears strange that any animal should possess an organ frequently subject to be injured. Lamarck would have been delighted with this fact had he known it when speculating (probably with more truth than usual with him) on the graduallyacquiredblindness of the Aspalax, a gnawer living underground, and of the Proteus, a reptile living in dark caverns filled with water, in both of which animals the eye is in an almost rudimentary state, and is covered with a tendinous membrane and skin.... In the Tucutuco, which, I believe, never comes to the surface of the ground, the eye is rather larger (than in the mole), but often rendered blind and useless, though without apparently causing any inconvenience to the animal: no doubt Lamarck would have said that the Tucutuco is now passing into the state of the Aspalax and Proteus.” Many years afterwards in the “Origin of Species” Darwin referred to the “erroneous views and grounds of opinion of Lamarck.”
No doubt some impulse to Darwin’s views in thisdirection would be due to his intercourse with Dr. Grant at Edinburgh, whose celebrated paper on the fresh-water sponge concludes with a declaration of his belief that species are descended from other species, and that they become improved in the course of modification. But previous to the occurrences of his voyage, we can find no stronger influence tending to make Darwin an evolutionist, than Lyell’s “Principles of Geology,” which, by showing constant and gradual change as the law of the world’s history now as in past periods, gave emphasis and point to all observations of change and succession in the living world. Indeed, in June, 1836, before Darwin’s voyage was over, Lyell writes to Sir John Herschel: “In regard to the origination of new species, I am very glad to find that you think it probable that it may be carried on through the intervention of intermediate causes. I left this rather to be inferred, not thinking it worth while to offend a certain class of persons by embodying in words what would only be a speculation. But the German critics have attacked me vigorously, saying, that by the impugning of the doctrine of spontaneous generation, and substituting nothing in its place, I have left them nothing but the direct and miraculous intervention of the First Cause, as often as a new species is introduced, and hence I have overthrown my own doctrine of revolutions carried on by a regular system of secondary causes.... When I first came to the notion, which I never saw expressed elsewhere, though I have no doubt it had all been thought out before, of a succession of extinction of species, and creation of new ones going on perpetually now, and through an indefinite period of the past, and to continue for ages to come, allin accommodation to the changes which must continue in the inanimate and habitable earth, the idea struck me as the grandest which I had ever conceived, so far as regards the attributes of the Presiding Mind.”
In a succeeding paragraph, Lyell very remarkably foreshadows Darwin’s “natural selection” and “struggle for existence.” He speaks of a species being rendered more prolific in order to perpetuate its existence; “but this would perhaps make it press too hard upon other species at other times. Now if it be an insect it may be made in one of its transformations to resemble a dead stick, or a leaf, or a lichen, or a stone, so as to be somewhat less easily found by its enemies; or if this would make it too strong, an occasional variety of the species may have this advantage conferred on it; or if this would be still too much, one sex of a certain variety.Probably there is scarcely a dash of colour on the wing or body of which the choice would be quite arbitrary, or which might not affect its duration for thousands of years.” The significance of the last sentence is immense, and when we reflect that this bold but cautious thinker was in constant intercourse with Darwin, we can readily comprehend why the second edition of the Journal was so enthusiastically dedicated to Lyell. On page 481 of the “Origin of Species,” Darwin acknowledges that the belief that species were immutable productions was almost unavoidable, as long as the history of the world was thought to be of short duration: which affords another proof how profoundly Lyell’s views on the long duration of the past history of the globe, and its modification by the slow operation of existing causes, influencedDarwin, and led him to comprehend how species might be modified.
We see Darwin, then, possessed of the idea that species are mutable, informed as to past and recent changes in the animal, plant, and physical world, seeking for causes which should suffice to produce modification of species by a continuous law. The next step in his progress was attention to domestic animals and cultivated plants. As he wrote in 1864 to Haeckel, one of his most brilliant followers: “In South America three classes of facts were brought strongly before my mind. Firstly, the manner in which closely-allied species replace species in going southward. Secondly, the close affinity of the species inhabiting the islands near South America to those proper to the continent. This struck me profoundly, especially the difference of the species in the adjoining islets in the Galapagos Archipelago. Thirdly, the relation of the living Edentata and Rodentia to the extinct species. I shall never forget my astonishment when I dug out a gigantic piece of armour like that of the living armadillo.
“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,7and after a time perceivedthat 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 realise 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 descendants from a common progenitor to diverge in character.”8
Malthus taught the inevitable tendency of all animal life to increase beyond the means of subsistence, and expounded the checks which begin to act when population increases too rapidly. But his book had lain unfruitful to naturalists since 1798, until Darwin read it,and with his special knowledge evolved from it the brilliant idea of the preservation of better-equipped races in the struggle for life, or, as Herbert Spencer put it, the survival of the fittest. At one bound the gloomy revelations of misery which the “Essay on Population” contained, were exchanged for the bright view of perpetual progress and improvement as being necessitated and brought about by the very struggle which ensued upon the natural increase of animal and plant life. Instead of struggle and pain, producing starvation and extinction merely, struggle and pain were seen as the conditions of development and improvement; the death of the lower, the life of the higher.
It is less profitable here to attempt to sketch the history of ideas of evolution in general, because that history as now revealed by research, and as detailed by many writers, was not the path along which Darwin travelled. Indeed, many of these ideas were not disinterred, and certainly were not brought to Darwin’s notice till after the publication of the “Origin of Species.” True he read Robert Chambers’s “Vestiges of Creation,” which, with its “powerful and brilliant style,” although displaying in its earlier editions “little accurate knowledge and a great want of scientific caution,” Darwin acknowledges to have done excellent service in calling attention to the subject, in removing prejudice, and in preparing the ground for the reception of analogous views. Herbert Spencer, in his Essay on the Development Hypothesis, first published inThe Leaderin March, 1852, and republished in his “Essays” (first series, 1858), argued that species have been modified owing to change of circumstances,basing his argument upon the analogy of domestic animals and plants, the changes which the embryos of many species undergo, and the difficulty of distinguishing species and varieties.
But we need not here dwell on the works of these thinkers, important as they are to the general history of evolutionary thought, because Darwin’s speculations had taken form long before, and he could be but slightly indebted to them. Far in advance of them he was at work collecting and testing the facts which alone could win general support for his views, and experimenting incessantly with the same object in view. Lyell and Hooker were in his confidence, and in Lyell’s letters we meet with references such as the following, dated November 13, 1854: “You probably know about this (the remarkable orchid, Catasetum), which will figure in C. Darwin’s book on ‘Species,’ with many other ‘ugly facts,’ as Hooker, clinging like me to the orthodox faith, calls these and other abnormal vagaries,” showing at the same time how completely Darwin was the leader, while his friends, advanced as they were, hung back. Again (Lyell to Hooker, July 25, 1856): “Whether Darwin persuades you and me to renounce our faith in species (when geological epochs are considered) or not, I foresee that many will go over to the indefinite modifiability doctrine.”
Further light is thrown on the progress of ideas on species by Sir Joseph Hooker’s admirably written Introductory Essay to the “Flora Novæ Zelandiæ,” dated November, 1853, in which he discusses among other questions, “The Limits of Species; their Dispersion andVariation.” While still adhering on the whole to the origin of species from single parents, or from one pair, and the permanence of specific characters, he insists that species vary more, and are more widely distributed, than is generally admitted, and that their distribution has been brought about by natural causes. In this essay he makes the following statements: “Mr. Darwin not only directed my earliest studies in the subjects of the distribution and variation of species, but has discussed with me all the arguments, and drawn my attention to many of the facts which I have endeavoured to illustrate in this essay. I know of no other way in which I can acknowledge the extent of my obligation to him, than by adding that I should never have taken up the subject in its present form but for the advantages I have derived from his friendship and encouragement.”
Appropriately enough, it was through Lyell and Hooker that the new theory was introduced to the public, and it was owing to them that Darwin did not obliterate his own claims to priority, and give them over to Alfred Russel Wallace, who had independently come to similar conclusions. The letter, dated June 30, 1858, in which the announcement was conveyed to the Linnean Society, deserves quotation, as being the authoritative and accurate record of the circumstances which launched the “Origin of Species” upon the world:
“The accompanying papers, which we have the honour of communicating to the Linnean Society, and which all relate to the same subject, viz., ‘The Lawswhich 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 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.“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, when the copy was read by Dr. Hooker, 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 October, 1857, by Mr.Darwin, in which he repeats his views, and which shows that these remained unaltered from 1839 to 1857.“3. An essay by Mr. Wallace, entitled ‘On the Tendency of Varieties to depart indefinitely from the Original Type.’ 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 theleading results of his labours, as well as those of his able correspondent, should together be laid before the public.”
“The accompanying papers, which we have the honour of communicating to the Linnean Society, and which all relate to the same subject, viz., ‘The Lawswhich 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 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.
“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, when the copy was read by Dr. Hooker, 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 October, 1857, by Mr.Darwin, in which he repeats his views, and which shows that these remained unaltered from 1839 to 1857.
“3. An essay by Mr. Wallace, entitled ‘On the Tendency of Varieties to depart indefinitely from the Original Type.’ 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 theleading results of his labours, as well as those of his able correspondent, should together be laid before the public.”
In these papers, read on July 1, 1858, Darwin’s share amounts to little more than six pages, yet within this space he describes the geometrical rate of increase of animals, the checks that occur, the effects of changed conditions, the natural selection of the better equipped forms resulting from the struggle for existence, and the influence of sexual selection. Wallace insists on essentially the same view, which he calls that of progression and continued divergence. “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 organised beings, their extinction and succession in past ages, and all the extraordinary modifications of form, instinct, and habits which they exhibit.” Those who read Wallace’s original essay can best appreciate the extraordinary simplicity and nobility of character which inclined the elder naturalist, who had so long held the same views, to step aside in favour of the younger man, who from different researches was led to such similar conclusions. It may here be added that Hooker, in the Introductory Essay to the “Flora Tasmaniæ,” dated November 4, 1859, before the publication of the “Origin of Species,” but after seeing much of it in manuscript, accepted and advocated the view that species are derivative and mutable, and developed it as regards the geographical distribution of plants.
DARWIN’S great work “On the Origin of Species by means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life,” was published in November, 1859. It begins with the simplest narrative of the events leading to its publication, and an apology for the imperfection of “this abstract.” The author is well aware, he says, that on most points he deals with, facts can be adduced which often apparently lead to conclusions directly opposite to his own. He states clearly the important truth that a mere belief in the origin of species by descent from other species is unsatisfactory until it can be shownhowspecies can have been modified so as to acquire their present remarkable perfection of structure and coadaptation. Consequently cases of observed modification of species are of the highest value, and precedence is given to the variation of animals and plants in a state of domestication.
The individuals belonging to the same variety of any of our long-cultivated animals or plants differ much more from each other than the individuals of any one species or variety in a state of nature. Darwin explains this bythe changed conditions of their life, excess or changed quality of food, climate, changed habits, &c. Thus man has effected remarkable changes in many species by consciously or unconsciously selecting particular qualities in the animals or plants kept for use or beauty. Domestic productions seem in fact to have become plastic in man’s hands, and the inheritance of acquired qualities by offspring is reckoned on as almost certain. The breeds of cattle, poultry, dogs, and pigeons, are striking examples.
Darwin, as he tells us, kept every breed of domestic pigeons he could purchase or obtain, in order to study their variations. In this he was himself reverting to the associations of childhood, when the beauty, variety, and tameness of The Mount pigeons at Shrewsbury were well known.
We can imagine the astonishment with which the “eminent fanciers” and members of the London Pigeon Clubs, whose acquaintance the great naturalist cultivated, received the simplicity, yet depth, of his inquiries, as he came among them day after day, utilising all their lore, and yet continually asking what they neither knew nor suspected the drift of. He began his study with a prepossession against the idea of the immense diversity of modern pigeons having originated from one common stock. Yet if such modification has taken place in any creature, pigeons may furnish an example, for they have been kept and bred for thousands of years, being recorded in Egypt about 3000b.c., and Pliny relates that their pedigree and race could be reckoned by the Romans of his time. “We cannot suppose that all the breeds were suddenly produced asperfect and as useful as we now see them; indeed, in several cases we know that this has not been their history. The key is man’s power of accumulative selection; nature gives successive variations; man adds them up in certain directions useful to him.” This is an undoubted fact, to which breeders and fanciers give far more emphatic testimony even than Darwin. As Lord Somerville said, speaking of what breeders have done for sheep, “It would seem as if they had chalked upon a wall a form perfect in itself, and then had given it existence.”
Side by side with conscious selection goes unconscious. Two breeders, breeding from similar stock, aiming at the same end, will get different results. Aiming at a particular result, they find that with it is associated some other of which they had not dreamed. Thus through long ages our cultivated vegetables and flowers have been produced, by always selecting the best variety, and sowing its seeds. The fact which Darwin notes, that our cultivated plants and domestic breeds date from so ancient a time that we know really nothing of their origin, has an important bearing on the great antiquity of man, then scarcely imagined, now generally accepted; seeing that all domestic development depends on a variability in living creatures, which man can not produce, but can only work upon.
That variation of species occurs in a state of nature Darwin proves not only by recorded facts, but by a consideration of the chaotic condition of species-description, owing to the differences between authors as to what are species and what are varieties, one observer describing adozen species where another reckons only one. If such divergence of opinion is possible between good observers, it is evident that there is no sufficiently clear rule for deciding what a species is, although for centuries naturalists have laboured to establish them. If species vary continually, and become modified, then this difficulty is explained.
But what is there in nature to answer to the breeder’s selection? Here comes in Darwin’s remarkable application and amplification of Malthus’s principle of population. “Nothing is easier,” he says, “than to admit in words the truth of the universal struggle for life, or more difficult—at least I have found it so—than constantly to bear this conclusion in mind. Yet unless it be thoroughly engrained in the mind, I am convinced that the whole economy of nature, with every fact on distribution, rarity, abundance, extinction, and variation will be dimly seen or quite misunderstood. We behold the face of nature bright with gladness; we often see superabundance of food; we do not see, or we forget, that the birds which are idly singing round us mostly live on insects or seeds, and are thus constantly destroying life; or we forget how largely these songsters, or their eggs, or their nestlings are destroyed by birds and beasts of prey; we do not always bear in mind, that though food may be now superabundant, it is not so at all seasons of each recurring year.” The proofs given of the enormous rate at which animals and plants tend to increase in numbers are very striking; even the elephant, the slowest breeder of all animals, would increase from one pair to fifteen millions in the fifth century, if no check existed.
Thus every animal and plant may be said to struggle for existence with those with which it competes for space, food, light, air. The numbers are kept down by heavy destruction at various periods of life. Take the case of seedling plants. Darwin had a piece of ground three feet long and two feet wide dug and cleared, so that no grown plants existed to check the growth of seedlings of native plants as they came up. He counted and marked all that came up, and out of 357 no fewer than 295 were destroyed, chiefly by slugs and insects. So in a little plot of long-mown turf, allowed to grow freely, out of twenty species nine perished in the struggle. Many further personal observations of the author are given: such as that the winter of 1854-5 destroyed four-fifths of the birds in his own grounds; that he has sometimes failed to get a single seed from wheat or other plants in his garden.
On the estate of a relative in Staffordshire the changes consequent on planting several hundred acres with Scotch fir were remarkable. In twenty-five years twelve species of conspicuous plants, and six different insectivorous birds had become settled and flourishing inhabitants in the plantations. The characteristic of the philosopher, who sees in the unconsidered trifles of others the material for his choicest discoveries, is well exemplified in his mode of observing the results of enclosure near Farnham, in Surrey. Here a multitude of self-sown firs sprang up in the enclosures, and Darwin went to examine into the cause of the strange phenomenon. Not a fir was in sight except some distant clumps. “But on looking closely between the stems of the heath, I found a multitude of seedlings and little trees, which had been perpetually browsed downby the cattle. In one square yard, at a point some hundred yards distant from one of the old clumps, I counted thirty-two little trees; and one of them, judging from the rings of growth, had during twenty-six years tried to raise its head above the stems of the heath, and had failed.”
The interdependence of animal upon animal, of animal upon plant, of plant upon animal, is enforced in many ways by Darwin. For instance, the visits of humble-bees are of special importance to the welfare of red clover; humble-bees are largely destroyed by field-mice; cats largely destroy field-mice near villages, and so favour humble-bees, and secondarily red clover. Every paragraph of the chapter on the struggle for existence is full of suggestion, and subversive of old imaginings. But Darwin’s knowledge is to him slight, his ignorance profound. Yet, he says, notwithstanding our ignorance, “we may console ourselves with the full belief that the war of nature is not incessant, that no fear is felt, that death is generally prompt, and that the vigorous, the healthy, and the happy survive and multiply.”
The great chapter on Natural Selection, or the preservation of favourable and the rejection of injurious variations, is crowded with striking passages. One of these vividly contrasts man’s selection with nature’s. “Man can act only on external and visible characters: nature cares nothing for appearances, except in so far as they may be useful to any being. She can act on every internal organ, on every shade of constitutional difference, on the whole machinery of life. Man selects only for his own good; nature only for that of the being she tends.Every selected character is fully exercised by her; and the being is placed under well-suited conditions of life.... Under nature, the slightest difference of structure or constitution may well turn the nicely-balanced scale in the struggle for life, and so be preserved. How fleeting are the wishes and efforts of man! how short his time! and consequently how poor will his products be, compared with those accumulated by nature during whole geological periods. Can we wonder, then, that nature’s productions should be far ‘truer’ in character than man’s productions; that they should be infinitely better adapted to the most complex conditions of life, and shouldplainly bear the stamp of far higher workmanship?” The words in italics certainly are a good answer to those who think Darwin had any tendency to depreciate the marvels of nature by bringing them under the law of natural selection. But we shall gain further light on this subject later on.
The main argument may be summed up thus: if variations beneficial to any creature occur, which cannot be doubted, the individuals in whom they occur will have the best chance of surviving and transmitting their qualities to their offspring. This natural selection will tend to produce divergence of character among offspring, and to intensify differences until they equal those between species or even genera. The same tendency to improvement brings about the decay and ultimate extinction of many lower and unimproved forms of life.
One of the best examples of Darwin’s style is in the passage comparing all members of the same class of beings to a great tree. “I believe this simile largelyspeaks the truth. The green and budding twigs may represent existing species; and those produced during each former year may represent the long succession of extinct species. At each period of growth all the growing twigs have tried to branch out on all sides, and to overtop and kill the surrounding twigs and branches, in the same manner as species and groups of species have tried to overmaster other species in the great battle for life. The limbs divided into great branches, and these into lesser and lesser branches, were themselves once, when the tree was small, budding twigs; and this connexion of the former and present buds by ramifying branches may well represent the classification of all extinct and living species in groups subordinate to groups. Of the many twigs which flourished when the tree was a mere bush, only two or three, now grown into great branches, yet survive and bear all the other branches; so with the species which lived during long-past geological periods, very few now have living and modified descendants. From the first growth of the tree many a limb and branch has decayed and dropped off; and these lost branches of various sizes may represent those whole orders, families, and genera which have now no living representatives, and which are known to us only from having been found in a fossil state. As we here and there see a thin straggling branch springing from a fork low down in a tree, and which by some chance has been favoured and is still alive on its summit, so we occasionally see an animal like the Ornithorhynchus or Lepidosiren, which in some small degree connects by its affinities two large branches of life, and which has apparently been saved fromfatal competition by having inhabited a protected station. As buds give rise by growth to fresh buds, and these, if vigorous, branch out and overtop on all sides many a feebler branch, so by generation I believe it has been with the great Tree of Life, which fills with its dead and broken branches the crust of the earth, and covers the surface with its ever-branching and beautiful ramifications.”
What may be the laws controlling or producing variation Darwin candidly tells us he does not know. Some authors, he says, believe it to be as much the function of the reproductive system to produce individual differences, or very slight deviations of structure, as to make the child like its parents. But we certainly do not know the precise effect of any change of conditions, or what changes may be entailed in other parts of an organism by given changes in one part.9
Why, if species are continually being modified, do we not see multitudes of transitional forms around us? How can the elaborate structure and special habits of a bat have been formed by the modification of some animal of entirely different habits? How can the marvellous perfections of the human eye or that of one of the higher animals be supposed to have arisen through natural selection? These questions Darwin answers with powerful effect; but for the details we must refer the reader to the book itself. Incidentally he refers to objections urged against the view that every detail ofstructure has been produced for the good of its possessor. He says plainly that if structures have been created for beauty in the eyes of man, or for mere variety, that is fatal to his theory. Yet he admits that many structures are of no direct use to their possessors; but they have been inherited from ancestors to whom they were of use, or they have arisen as correlated changes or in dependence on some other cause, where use and benefit have been primary.
In dealing with Instinct, we see Darwin personally studying ants and bees in their social habits. The idea of ants making slaves is to him “odious,” which we can well understand after his references to slavery in South America. For three years, during June and July, he watched for many hours several ants’ nests in Surrey and Sussex to see whether the slaves ever left the nest. One day he witnessed a migration of ants from one nest to another, the masters carefully carrying their slaves in their jaws. Again, he saw a party attempting to carry off slaves, succeeding, however, only in carrying their corpses off for food to the nest. Darwin then dug up a small group of pupæ of the slave species from another nest, and put them down near the place of combat. They were eagerly seized and carried off by the tyrants, “who perhaps fancied that, after all, they had been victorious in their late combat.” At the same time the slave-owners were able to distinguish instantly the pupæ of another species, showing much terror at sight of them; yet they ultimately took heart, and carried them off.
The cell-making instinct of the hive-bee, “the most wonderful of all known instincts,” as Darwin terms it, wasclosely studied. The comb, “so beautifully adapted to its end,” he enthusiastically admired. Yet he finds gradation among bees, and can imagine a method by which this beautiful construction, has been gradually developed. His ideas were tested by setting bees to work on a solid piece of wax between two combs. The detailed account of these experiments is most instructive. It is quite charming to mentally follow the patient experimenter covering the edges of a single cell or the extreme margin of a growing comb with a thin layer of vermilion wax, and soon proving that many bees work in succession at a single cell by the rapid diffusion of the vermilion colouring as delicately as a painter could have done it, atoms of the coloured wax being removed and worked into the growing cells all round.10“It was really curious,” Darwin says, “to note in cases of difficulty, as when two pieces of comb met at an angle, how often the bees would entirely pull down and rebuild in different ways the same cell, sometimes recurring to a shape which they had at first rejected.” Here surely he was watching evolution in that slow, gradual process which appears to be the rule.
The castes of neuter ants, constituting as they did “by far the most serious special difficulty” Darwin had encountered, were similarly studied; but, as expected, gradations were found connecting them, although the extremes differ markedly in shape and size. The case ismost interesting, because these castes could only be developed if the variations which produced them were profitable to the community; “for no amount of exercise, or habit, or volition, in the utterly sterile members of a community could possibly have affected the structure or instincts of the fertile members, which alone leave descendants.” This fact Darwin considers to be demonstrative against Lamarck’s doctrine. At the same time, he admits that instincts are not always perfect, and are liable to make mistakes; and that no instinct has been produced for the exclusive good of other animals, but that each animal takes advantage of the instincts of others. It is to him “far more satisfactory to look at such instincts as the young cuckoo ejecting its foster-brothers, ants making slaves, the larvæ of ichneumonidæ feeding within the live bodies of caterpillars, not as specially endowed or created instincts, but as small consequences of one general law, leading to the advancement of all organic beings, namely, multiply, vary, let the strongest live and the weakest die.” And here Darwin strikes one of his truest and most helpful notes. Itisfar more satisfactory to contemplate the rapine and war of nature as incidents which aid in working out a grand progress than as multitudinous cruelties, working no good, and in past ages of unknown length merely preluding the struggle and rapine through which man works out his rise or fall. If we agonise that we and our descendants may rise, life is worth living.
We cannot follow in detail the profoundly suggestive chapters on Hybridism, on the Imperfection of the Geological Record, on the Geological Succession of Organic Beings, on the Geographical Distribution, andon the Mutual Affinity of Plants and Animals. The first of these is one of the most difficult portions of the subject, and yet remains as a stumbling-block of science by its apparently inexplicable phenomena. The author throws on the past history of life on the earth the glamour of a fairy record, as he contemplates the infinite number of generations, which the mind cannot grasp, which must have succeeded one another in the long roll of years, the limited extent to which at any time fossil remains have been preserved, the immense amount of destruction of such records which has taken place; and hence argues most powerfully how improbable it is that the transitional stages from species to species should have been handed down and also (another rare chance) have been laid open to us. The great array of facts about extinct animals and plants is shown to be consistent with, and to be largely explained by, descent with modification, and to be incomprehensible on any other view. The eccentric contrasts and parallelisms displayed in the geographical distribution of plants and animals, the striking effects of barriers such as mountains, deserts, and seas, the phenomena of dispersion of living creatures, the indications of old glacial periods in the present distribution of Alpine plants, the strange distribution of fresh-water animals and plants, the specialities of oceanic islands, and many other subjects of a like kind, are dealt with, all being turned to advantage, and shown to give strong support to Darwin’s view.
Classification and classifiers are all made to bear testimony in the same direction. Morphology, which, in the hands of Huxley, Haeckel, Gegenbaur, Ray Lankester,and Balfour has, since the first issue of the “Origin of Species,” grown into a coherent science, based on embryology, was even then seen by Darwin to yield evidence for his views. Examining very young animals, he found that in very distinct races of dogs and horses the young had by no means acquired their adult differences. He compared pigeons of extremely various breeds twelve hours after being hatched, and found their differences incomparably less than in the full-grown birds. How immensely morphological science has progressed since Darwin directed investigation into this profitable line would need a separate treatise to show; but it is not too much to say that embryology alone, without other evidence, would now suffice to prove the doctrine of descent with adaptive modification.
Rudimentary organs, again, strange appearances, like the presence of teeth in unborn whales and in the front of the upper jaws of unborn calves, the rudimentary wings of many insects, the rudimentary stamens or pistils of many flowers, are all swept into the Darwinian net. “Nothing can be plainer than that wings are formed for flight; yet in how many insects do we see wings so reduced in size as to be utterly incapable of flight, and not rarely lying under wing-cases, firmly soldered together?” These phenomena are all explicable if descent with modification is true.
Approaching the close of his work, the author expressed his doubts of being able to convert naturalists of long standing to his views; but based his main hopes on young and rising men approaching these questions without prejudices. He put some puzzling questions, however,to those who might oppose him. Did they really believe that at innumerable periods in the earth’s history certain atoms had been commanded suddenly to flash into living tissues? Were animals and plants created as eggs or seed or as full grown? At each act of creation was one individual or were many produced? For himself, he came to the conclusion that all organic beings had descended from some one primordial form into which life was first breathed.
On this view Darwin predicted that a great increase of interest in many departments of natural history would arise. “When we no longer look at an organic being as a savage looks at a ship, as at something wholly beyond his comprehension; when we regard every production of nature as one which has had a history; when we contemplate every complex structure and instinct as the summing up of many contrivances, each useful to the possessor, nearly in the same way as when we look at any great mechanical invention as the summing up of the labour, the experience, the reason, and even the blunders of numerous workmen; when we thus view each organic being, how far more interesting—I speak from experience—will the study of natural history become.... The whole history of the world, as at present known, although of a length quite incomprehensible to us, will hereafter be recognized as a mere fragment of time compared with the ages which have elapsed since the first creature, the progenitor of innumerable extinct and living descendants, was created.... We may look forward with some confidence to a secure future of equally inappreciable length. And as natural selection works solelyby and for the good of each being, all corporeal and mental endowments will tend to progress towards perfection.” The concluding sentence of the “Origin of Species” has become one of our classical quotations. “There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.”
This is not the place to give a history of the criticisms and discussions which arose in regard to “The Origin of Species,” especially as Darwin himself took no public part in them, except by the alterations made in successive editions. As indicating the tone of prominent critical organs, we may note thatThe Athenæum(November 19, 1859) acknowledges there is something poetical in the theory. “If a monkey has become a man, what may not a man become?” Neither book, author, nor subject being ordinary, “the work deserves attention.”The Edinburgh Reviewconsidered that the author left the question very nearly where he found it. Failing to find original observations adequate even to give a colour to the hypothesis, the reviewer sought to find flaws in the author’s mode of reasoning, and concluded that “we are called upon to accept a hypothesis on the plea of want of knowledge.” Defective information, vagueness, and incompleteness are charged upon the man whom we now delight to honour; “intellectual husks,” we are told; are all that he offers. Professor Huxley, who lectured at the Royal Institution, on February 10, 1860, on “Species andRaces and their Origin,” and brought forward Darwin’s investigations as exemplifying that application of science to which England owes her greatness, was told that it more truly paralleled “the abuse of science to which a neighbouring nation—some seventy years since—owed its temporary degradation.” And the professor was accused of audaciously seeking to blind his audience. Samuel Wilberforce, then Bishop of Oxford, was equally denunciatory inThe Quarterly. He hopes that “this flimsy speculation” will be completely put down. “It is a dishonouring view of nature.... Under such influences,” says the courtly bishop, “a man soon goes back to the marvelling stare of childhood at the centaurs and hippogriffs of fancy; or, if he is of a philosophic turn, he comes, like Oken, to write a scheme of creation under a ‘sort of inspiration,’ but it is the frenzied inspiration of the inhaler of mephitic gas. The whole world of nature is laid for such a man under a fantastic law of glamour, and he becomes capable of believing anything; and he is able, with a continually growing neglect of all the facts around him, with equal confidence and equal delusion, to look back to any past and to look on to any future.”11