Charles Darwin

In spite of the still continued demurrer of not a few among the leading evolutionists, it is probable, I think, that Darwin's prophecy on this matter will yet be justified by the verdict of time. For the opposition to the doctrine of sexual selection proceeds almost invariably, as it seems to me, from those persons who still desire to erect an efficient barrier of one sort or another between the human and animal worlds; while on the contrary the theory in question is almost if not quite universally accepted by just those rigorously evolutionary biologists who are freest from preconceptions or special a priori teleological objections of any kind whatever. The half of the doctrine which deals with the law of battle, indeed, can hardly be doubted by any competent naturalist; the other half, which deals with the supposed æsthetic preferences of the females, is, no doubt, distasteful to certain thinkers because it seems to imply the existence in the lower animals of a sense of beauty which many among us are not even now prepared generously to admit. The desire to arrogate to mankind alone all the higher faculties either of sense or intellect has probably much to do with the current disinclination towards the Darwinian idea of sexual selection. Thinkers who allow themselves to be emotionally swayed by such extraneous considerations forget that the beautiful is merely that which pleases; that beauty has no external objective existence; and that the range of taste, both among ourselves and among animals at large, is practically infinite. The greatest blow ever aimed at the Darwinian theory of sexual selection was undoubtedly that dealt out by Mr. Alfred Russel Wallace (et tu, Brute!) in his able and subtle article on the Colours of Animals in 'Macmillan's Magazine,' since reprinted in his delightful work on 'Tropical Nature.' Wallace there urges with his usual acuteness, ingenuity, and skill several fundamental objections to the Darwinian hypothesis of no little importance and weight. But it must always be remembered (with all due respect to the joint discoverer of natural selection) that Mr. Wallace himself, after publishing his own admirable essay on the development of man, drew back aghast in the end from the full consequences of his own admission, and uttered his partial recantation in the singular words, 'Natural selection could only have endowed the savage with a brain a little superior to that of an ape.' It seems probable that in every case an analogous desire to erect a firm barrier between man and brute by positing the faculty for perceiving beauty as a special quasi-divine differentia of the human race has been at the bottom of the still faintly surviving dislike amongst a section of scientific men to sexual selection. Nevertheless, a candid and impartial critic would be compelled frankly to admit that Darwin's admirable theory of courtship has not on the whole proved so generally acceptable to the biological world up to the present time as his greater and far more comprehensive theory of survival of the fittest. It still waits for its final recognition, towards which it is progressing more rapidly and surely every day it lives.

CHAPTER X

VICTORY AND REST

The last eleven years of Darwin's life were spent in enforcing and developing the principles already reached, and in enjoying the almost unchequered progress of the revolution he had so unconsciously to himself succeeded in inaugurating.

Only one year elapsed between the publication of the 'Descent of Man' and that of its next important successor, the 'Expression of the Emotions.' The occasion of this learned and bulky treatise in itself stands as an immortal proof of the conscientious way in which Darwin went to work to anticipate the slightest and most comparatively impertinent possible objections to his main theories. Sir Charles Bell, in one of the quaintly antiquated Bridgwater treatises – those marvellous monuments of sadly misplaced teleological ingenuity – had maintained that man was endowed with sundry small facial muscles solely for the sake of expressing his emotions. This view was so obviously opposed to the belief in the descent of man from some lower form, 'that,' says Darwin, 'it was necessary for me to consider it;' and so he did, in a lengthy work, where the whole subject is exhaustively treated, and Bell's idea is completely pulverised by the apt allegation of analogous expressions in the animal world. In his old age Darwin grew, in fact, only the more ceaselessly and wonderfully industrious. In 1875, after three years of comparative silence, came the 'Insectivorous Plants,' a work full of minute observation on the habits and manners of the sundew, the butterwort, the Venus's fly-catcher, and the various heterogeneous bog-haunting species known by the common name of pitcher plants. The bare mass and weight of the facts which Darwin had collected for the 'Origin of Species' might well-nigh have stifled the very existence of that marvellous book: it was lucky that the premature publication of Wallace's paper compelled him to hurry on his 'brief abstract,' for if he had waited to select and arrange the whole series of observations that he finally published in his various later justificatory volumes, we might have looked in vain for the great systematic and organising work, which would no doubt have been 'surcharged with its own weight, and strangled with its waste fertility.' But the task that he himself best loved was to watch in minute detail the principles whose secret he had penetrated, and whose reserve he had broken, working themselves out before his very eyes, naked and not ashamed – to catch Actæon-like the undraped form of nature herself in the actual process of her inmost being. He could patiently observe the red and slimy hair-glands of the drosera closing slowly and remorselessly round the insect prey, and sucking from their bodies with sensitive tentacles the protoplasmic juices denied to its leaves by the poor and boggy soil, on which alone its scanty rootlets can properly thrive. He could watch the butterwort curving round the edges of its wan green foliage upon the captured limbs of fly or aphis. He could note how the serried mass of finger-like processes in the utricles of the bladderwort slowly absorb organic matter from the larva of a gnat, or the minute water-insects entangled within its living and almost animated lobster-pot. He could track the long line of treacherous honey-glands by which the sarracenia entices flies into the festering manure-wells of its sticky pitchers. The minuteness and skill of all his observations on these lesser problems of natural selection inevitably inspired faith among outsiders in the cautious judgment of the observer and experimenter; and day by day throughout his later years the evidence of the popular acceptance of his doctrine, and of the dying away of the general ridicule with which it was first received by the unlearned public, was very gratifying to the great naturalist.

A year later, in 1876, came the 'Effects of Cross and Self Fertilisation in the Vegetable Kingdom.' So far as regarded the world of plants, especially with respect to its higher divisions, this work was of immense theoretical importance; and it also cast a wonderful side-light upon the nature of that strange distinction of sex which occurs both in the vegetable and animal kingdom, and in each is the concomitant – one might almost say the necessary concomitant – of high development and complex organisation. The great result attained by Darwin in his long and toilsome series of experiments on this interesting subject was the splendid proof of the law that cross-fertilisation produces finer and healthier offspring, while continuous self-fertilisation tends in the long run to degradation, degeneration, and final extinction.

Here as elsewhere, however, Darwin's principle does not spring spontaneous, like Athene from the head of Zeus, a goddess full-formed, uncaused, inexplicable: it arises gradually by a slow process of development and modification from the previous investigations of earlier biologists. At the close of the last century, in the terrible year of upheaval 1793, a quiet German botanist, Christian Konrad Sprengel by name, published at Berlin his long unheeded but intensely interesting work on the 'Fertilisation of Flowers.' In the summer of 1789, while all Europe was ablaze with the news that the Bastille had been stormed, and a new era of humanity begun, the calm and peaceful Pomeranian observer was noting in his own garden the curious fact that many flowers are incapable of being fertilised without the assistance of flying insects, which carry pollen from the stamens of one blossom to the sensitive surface or ovary of the next. Hence he concluded that the secretion of honey or nectar in flowers, the contrivances by which it is protected from rain, the bright hues or lines of the corolla, and the sweet perfume distilled by the blossoms, are all so many cunning devices of nature to ensure fertilisation by the insect-visitors. Moreover, Sprengel observed that many flowers are of one sex only, and that in several others the sexes do not mature simultaneously; 'so that,' said he, 'nature seems to intend that no flower shall be fertilised by means of its own pollen.' Indeed, in some instances, as he showed by experiments upon the yellow day lily, plants impregnated from their own stamens cannot be made to set seed at all. 'So near,' says his able successor, Hermann Müller, 'was Sprengel to the distinct recognition of the fact that self-fertilisation leads to worse results than cross-fertilisation, and that all the arrangements which favour insect-visits are of value to the plant itself, simply because the insect-visitors effect cross-fertilisation!' As in most other anticipatory cases, however, it must be here remarked that Sprengel's idea was wholly teleological: he conceived of nature as animated by a direct informing principle, which deliberately aimed at a particular result; whereas Darwin rather came to the conclusion that cross-fertilisation as a matter of fact does actually produce beneficial results, and that therefore those plants which varied most in the direction of arrangements for favouring insect-visits were likely to be exceptionally fortunate in the struggle for existence against competitors otherwise arranged. It is just the usual Darwinian substitution of an efficient for a final cause.

Even before Sprengel, Kölreuter had recognised, in 1761, that self-fertilisation was avoided in nature; and his observations and experiments on intercrossing and on hybridism were largely relied upon by Darwin himself, to whom they suggested at an early period many fruitful lines of original investigation. In 1799, again, Andrew Knight, following up the same line of thought in England as Sprengel in Germany, declared as the result of his close experiments upon the garden pea, that no plant ever fertilises itself for a perpetuity of generations. But Knight's law, not being brought into causal connection with any great fundamental principle of nature, was almost entirely overlooked by the scientific world until the publication of Darwin's 'Origin of Species,' half a century later. The same neglect also overtook Sprengel's immensely interesting and curious work on fertilisation of flowers. The world, in fact, was not yet ready for the separate treatment of functional problems connected with the interrelations of organic beings; so Knight and Sprengel were laid aside unnoticed on the dusty top bookshelves of public libraries, while the dry classificatory and systematic biology of the moment had it ail its own way for the time being on the centre reading-tables. So many separate and independent strands of thought does it ultimately require to make up the grand final generalisation which the outer world attributes in its totality to the one supreme organising intelligence.

But in the 'Origin of Species' itself Darwin reiterated and emphasised Knight's law as a general and all-pervading principle of nature, placing it at the same time on broader and surer biological foundations by affiliating it intimately upon his own great illuminating and unifying doctrine of natural selection. He also soon after rescued from oblivion Sprengel's curious and fairy-like book, showing in full detail in his work on orchids the wonderful contrivances by which flowers seek to attract and to secure the assistance of insects for the impregnation of their embryo seeds. In the 'Variation of Animals and Plants under Domestication,' he further showed that breeding in-and-in diminishes the strength and productiveness of the offspring; while crossing with another stock produces, on the contrary, the best possible physical results in both directions. And now at last, in the 'Effects of Cross and Self fertilisation,' he proved by careful and frequently repeated experiments that a constant infusion of fresh blood (so to speak) is essential to the production of the healthiest offspring. In the words of his own emphatic summing up, 'Nature abhors perpetual self-fertilisation.'

The immediate result of these new statements and this fresh rationale of Knight's law was to bring down Sprengel forthwith from the top shelf, where he had languished ingloriously for seventy years, and to set a whole school of ardent botanical observers working hard in the lines he had laid down upon the mutual correlations of insects and flowers. A vast literature sprang up at once upon this enchanting and long-neglected subject, the most eminent workers in the rediscovered field being Delpino in Italy, Hildebrand and Hermann Müller in Germany, Axel in Sweden, Lubbock in England, and Fritz Müller in tropical South America. Darwin found the question, in fact, almost taken out of his hands before he had time himself to treat of it; for Hildebrand's chief work was published as early as 1867, while Axel's appeared in 1869, both of them several years earlier than Darwin's own final essay on the subject in the 'Effects of Cross and Self Fertilisation.' No statement, perhaps, could more clearly mark the enormous impetus given to researches in this direction than the fact that D'Arcy Thompson, in his appendix to Müller's splendid work on the 'Fertilisation of Flowers,' has collected a list of no less than eight hundred and fourteen separate works or important papers bearing on that special department of botany, almost all of them subsequent in date to the first publication of the 'Origin of Species.' So widely did the Darwinian wave extend, and so profoundly did it affect every minute point of biological and psychological investigation.

Each of these later works of Darwin's consists, as a rule, of an expansion of some single chapter or paragraph in the 'Origin of Species;' or, to speak more correctly, of an arrangement of the materials collected and the experiments designed for that particular portion of the great projected encyclopædia of evolutionism, of which the 'Origin of Species' itself was but a brief anticipatory summary or rough outline. Thus, the book on Orchids, published in 1862, is already foreshadowed in a part of the chapter on the Difficulties of the Theory of Natural Selection; the 'Movements and Habits of Climbing Plants' (1865) is briefly summarised by anticipation in the long section on Modes of Transition; the 'Variation of Animals and Plants under Domestication' (1868) consists of the vast array of pièces justificatives for the first chapter of the 'Origin of Species;' and the germ of the 'Cross and Self Fertilisation' (1876) is to be seen in the passage 'On the Intercrossing of Individuals' in Chapter IV. of the same work. It was well indeed that Darwin began by publishing the shorter and more manageable abstract; the half, as the wise Greek proverb shrewdly remarks, is often more than the whole; and a world that eagerly devoured the first great deliverance of the Darwinian principle, might have stood aghast had it been asked to swallow it piecemeal in such gigantic treatises as those with which its author afterwards sought thrice to vanquish all his foes and thrice to slay the slain.

Yet, with each fresh manifestation of Darwin's inexhaustible resources, on the other hand, the opposition to his principles grew feebler and feebler, and the universality of their acceptance more and more pronounced, till at last, among biologists at least, not to be a Darwinian was equivalent to being hopelessly left behind by the general onward movement of the time. In 1874 Tyndall delivered his famous address at the Belfast meeting of the British Association; and in 1877, from the same presidential chair at Plymouth, Allen Thomson, long reputed a doubtful waverer, enforced his cordial adhesion to the Darwinian principles by his inaugural discourse on 'The Development of the Forms of Animal Life.' A new generation of active workers, trained up from the first in the evolutionary school, like Romanes, Ray Lankester, Thistleton Dyer, Balfour, Sully, and Moggridge, had now risen gradually around the great master; and in every direction he could see the seed he had himself planted being watered and nourished in fresh soil by a hundred ardent and enthusiastic young disciples. Even in France, ever irresponsive to the touch of new ideas of alien origin, Colonel Moulinié's admirable and sympathetic translations were beginning to win over to the evolutionary creed many rising workers; while in Germany, Victor Carus's excellent versions had from the very first brought in the enthusiastic Teutonic biologists with a congenial 'swarmery' to the camp of the Darwinians. Correspondents from every part of the world kept pressing fresh facts and fresh applications upon the founder of the faith; and Darwin saw his own work so fast being taken out of his hands by specialist disciples that he abandoned entirely his original intention of publishing in detail the basis of his first book, and contented himself instead with tracing out minutely some minor portions of his contemplated task as specimens of evolutionary method.

In 1877, in pursuance of this changed purpose, Darwin published his book on 'Forms of Flowers,' in which he dealt closely with the old problem of differently shaped blossoms on plants of the same species. It had long been known, to take a single example, that primroses existed in two forms, the pin-eyed and the thrum-eyed, of which the former has the pin-like summit of the pistil at the top of the tube, and the stamens concealed half way down its throat; while in the latter these relative positions are exactly reversed, the stamens answering in place to the pistil of the alternative form with geometrical accuracy. As early as 1862 Darwin had shown, in the 'Journal of the Linnean Society,' that this curious arrangement owed its development to the greater security which it afforded for cross-fertilisation, because in this way each flower had to be impregnated with the pollen, from a totally distinct blossom, growing on a different individual plant. In a series of successive papers read before the same Society in the years between 1863 and 1868, he had extended a similar course of explanation to the multiform flowers of the flaxes, the loosestrifes, the featherfoil, the auricula, the buckbean, and several other well-known plants. At last, in 1877, he gathered together into one of the now familiar green-covered volumes the whole of his observations on this strange peculiarity, and proved by abundant illustration and experiment that the diversity of form is always due through natural selection to the advantage gained by perfect security of cross-fertilisation, resulting as it invariably does in the production of the finest, strongest, and most successful seedlings. Any variation, however peculiar, which helps to ensure this constant infusion of fresh blood is certain to be favoured in the struggle for life, owing to the superior vitality of the stock it begets. But it is worthy of notice, as showing the extreme minuteness and exhaustiveness of Darwin's method on the small scale, side by side with his extraordinary and unusual power of rising to the very highest and grandest generalisations, that the volume which he devoted to the elucidation of this minor factor in the question of hereditary advantages runs to nearly as many pages as the last edition of the 'Origin of Species' itself. So great was the wealth of observation and experiment which he could lavish upon the solution of a single, small, incidental problem.

Even fuller in minute original research was the work which Darwin published in 1880, on 'The Power of Movement in Plants,' detailing the result of innumerable observations on the seemingly irresponsible yet almost purposive rotations of the growing rootlets and young stems of peas and climbers. Anyone who wishes to see on what a wide foundation of irrefragable fact the great biologist built up the stately fabric of his vast theories cannot do better than turn for instruction to this remarkable volume, which the old naturalist gave to the world some time after passing the allotted span of threescore years and ten.

It was in the same year (1880) that Huxley delivered at the Royal Institution his famous address on the Coming of Age of the 'Origin of Species.' The time was a favourable one for reviewing the silent and almost unobserved progress of a great revolution. Twenty-one years had come and gone since the father of modern scientific evolutionism had launched upon the world his tentative work. In those twenty-one years the thought of humanity had been twisted around as upon some invisible pivot, and a new heaven and a new earth had been presented to the eyes of seers and thinkers. One-and-twenty years before, despite the influence of Hutton and of Lyell, the dominant view of the earth's past history revealed but one vast and lawless succession of hideous catastrophes. Wholesale creations and wholesale extinctions, world-wide cataclysms followed by fresh world-wide births of interwoven faunas and floras – these, said Huxley, were the ordinary machinery of the geological epic brought into fashion by the misapplied genius of the mighty Cuvier. One-and-twenty years after, the opponents themselves had given up the game in its fullest form as lost beyond the hope of possible restitution. Some hesitating thinkers, it is true, while accepting the evolutionary doctrine more or less in its earlier form, like Mivart and Meehan, yet refused their assent on one ground or another to the specific Darwinian doctrine of natural selection. Others, like Wallace, made a special exception with regard to the development of the human species, which they supposed to be due to other causes from those implied in the remainder of the organic scale. Yet on the whole, biological science had fairly carried the day in favour of evolution, in one form or another, and not even the cavillers dared now to suggest that whole systems of creation had been swept away en bloc, and remade again in different forms for a succeeding epoch, in accordance with the belief which was almost universal among geologists up to the exact moment of the publication of Darwin's masterpiece.

During the twenty-one years, too, as Huxley likewise pointed out, an immense number of new facts had come to strengthen the hands of the evolutionists at the very point where they had before felt themselves most openly vulnerable. Palæontology had supplied many of those missing links in the organic chain whose absence from the interrupted and imperfect geological record had been loudly alleged against the Darwinian hypothesis in the earlier days of struggle and hesitation. Two years after the publication of the 'Origin of Species,' the discovery of a winged and feathered creature, happily preserved for us in the Solenhofen slates, with lizard-like head and teeth and tail, and bird-like pinions, feet, and breast, had bridged over in part the great gap that yawns between the existing birds and reptiles. A few years later, new fossil reptilian forms, erect on their hind legs like kangaroos, and with very singular peculiarities of bony structure, had helped still further to show the nature of the modifications by which the scale-bearing quadruped type passed slowly into that of the feather-bearing biped. In 1875, again, Professor Marsh's discovery of the toothed birds in the American cretaceous strata completed the illustrative series of transitional forms over what had once been the most remarkable existing break in the continuity of organic development. Similarly, Hofmeister's investigations in the vegetable world brought close together the flowering and flowerless plants, by indicating that the ferns and the horsetails were connected in curious unforeseen ways, through the pill-worts and club-mosses, with the earliest and simplest of forest trees, the firs and the puzzle-monkeys. In minor matters like progress was continually reported on every side. Gaudry found among the fossils of Attica the successive stages by which the ancient and undeveloped civets passed into the more modern and specialised tribe of the hyænas; Marsh traced out in Western America the ancestry of the horse from a five-toed creature no bigger than a fox, through intermediate four-toed and three-toed forms, to the existing single solid-hoofed type with its digits reduced to the minimum of unity; and Filhol unearthed among the phosphorites of Quercy the common progenitor of the most distinct among the recent carnivores, the cats and the dogs, the plantigrade bears and the digitigrade pumas. 'So far as the animal world is concerned,' Professor Huxley said in conclusion, reviewing these additions to the evidence upon that memorable occasion, 'evolution is no longer a speculation but a statement of historical fact.' Of Darwin himself he remarked truly, 'He has lived long enough to outlast detraction and opposition, and to see the stone that the builders rejected become the head-stone of the corner.'

It was in 1881 that Darwin published his last volume, 'The Formation of Vegetable Mould through the Action of Worms.' In this singularly fascinating and interesting monograph he took in hand one of the lowliest and humblest of living forms, the common earthworm, and by an exhaustive study of its habits and manners strove to show how the entire existence of vegetable mould – the ordinary covering of fertile soil upon the face of the earth – is due to the long but unobtrusive action of these little-noticed and ever-active architects. By the acids which they evolve, they appear to aid largely in the disintegration of the stone beneath the surface; by their constant practice of eating fallen leaves, which they drag down with them into their subterranean burrows, they produce the fine castings of soft earth, so familiar to everybody, and thus reinstate the coating of humus above the bare rock as often as it is washed away again in the course of ordinary denudation by the rain and the torrents. It is true that subsequent investigation has shown the possibility of vegetable mould existing under certain conditions without the intervention of worms to any marked extent; but, as a whole, there can be little doubt that over most parts of the world the presence of soil, and therefore of the vegetable growth rooted in it, is entirely due to the unsuspected yet ceaseless activity of these humble creatures.

The germ of the earthworm theory appears to me to have been first suggested to Darwin's mind by a passage in a work where one would little have suspected it – White's 'Natural History of Selborne.' 'Earthworms,' says the idyllic Hampshire naturalist, 'though in appearance a small and despicable link in the chain of nature, yet, if lost, would make a lamentable chasm. For to say nothing of half the birds, and some quadrupeds, which are almost entirely supported by them, worms seem to be the great promoters of vegetation, which would proceed but lamely without them, by boring, perforating, and loosening the soil, and rendering it pervious to rains and the fibres of plants, by drawing straws and stalks of leaves into it; and, most of all, by throwing up such infinite numbers of lumps of earth, called worm-casts, which, being their excrement, is a fine manure for grain and grass. Worms probably provide new soils for hills and slopes where the rain washes the earth away; and they affect slopes, probably, to avoid being flooded. Gardeners and farmers express their detestation of worms; the former, because they render their walks unsightly, and make them much work; and the latter, because, as they think, worms eat their green corn. But these men would find, that the earth without worms would soon become cold, hard-bound, and void of fermentation; and, consequently, sterile.'

If Darwin ever read this interesting passage, which he almost certainly must at some time have done, it would appear that he had overlooked it in later life; for he, who was habitually so candid and careful in the acknowledgment of all his obligations, however great or however small, does not make any mention of it at all in his 'Vegetable Mould,' though he alludes incidentally to some other observations of Gilbert White's on the minor habits and manners of earthworms. But whether Darwin was originally indebted to White or not for the foundation of his theory on the subject of mould, the important point to notice is really this, that what with the observant parson of Selborne was but a casual glimpse, the mere passing suggestion of a fruitful idea, became with Darwin, in his wider fashion, a carefully elaborated and powerfully buttressed theory, supported by long and patient investigation, ample experiment, and vast collections of minute facts. The difference is strikingly characteristic of the strong point of Darwin's genius. While he had all the breadth and universality of the profoundest thinkers, he had also all the marvellous and inexhaustible patience of the most precise and special microscopical student.

For years, indeed, Darwin studied the ways and instincts of the common earthworm with the same close and accurate observation which he gave to every other abstruse subject that engaged in any way his acute intellect. The lawyer's maxim, 'De minimis lex non curat,' he used to say, never truly applies to science. As early as the year 1837 he read a paper, before the Geological Society of London, 'On the Formation of Mould,' in which he developed with some fulness the mother idea of his complete theory on the earthworm question. He there showed that layers of cinders, marl, or ashes, which had been strewn thickly over the surface of meadows, were found a few years after at a depth of some inches beneath the turf, yet still forming in spite of their burial a regular and fairly horizontal stratum. This apparent sinking of the stones, he believed, was due to the quantity of fine earth brought up to the surface by worms in the form of castings. It was objected to his theory at the time that the work supposed to be accomplished by the worms was out of all reasonable proportion to the size and numbers of the alleged actors. Here Darwin's foot was on his native heath; he felt himself immediately on solid ground again. The cumulative importance of separately infinitesimal elements is indeed the very keynote and special peculiarity of the great biologist's method of thinking. He had found out in very truth that many a little makes a mickle, that the infinitely small, infinitely repeated, may become in process of infinite years infinitely important. So he set himself to work, with characteristic contempt of time, to weigh and measure worms and worm-castings.

He began by keeping tame earthworms in flower-pots in his own house, counting the number of worms and burrows in certain measured spaces of pasture or garden, and starting his long and slow experiment in his field at Down already alluded to. He tried issues on their senses, on their instincts, on their emotions, on their intelligence; he watched them darting wildly like rabbits into their holes when alarmed from without, overcoming engineering difficulties in dragging down oddly-shaped or unfamiliar leaves, and protecting the open mouths of their tunnels from intruders with a little defensive military glacis of rounded pebbles. He found that more than 53,000 worms on an average inhabit every acre of garden land, and that a single casting sometimes weighs as much as three ounces avoirdupois. Ten tons of soil per acre pass annually through their bodies, and mould is thrown up by them at an average rate of 22 inches in a century. Careful observations on the stones of Stonehenge; on the tiled floors of buried buildings; on Roman ruins at Silchester and Wroxeter, and on his own meadows and pastures at Down, finally enabled the cautious experimenter to prove conclusively the truth of his thesis, and to present to the world the despised earthworm in a new character, as the friend of man and of agriculture, the producer and maintainer of the vegetable mould on our hills or valleys, and the prime cause of the very existence of that cloak of greensward that clothes our lawns, our fields, and our pleasure-grounds.

It was his last work. Persistent ill-health and equally persistent study for seventy-three years had broken down a constitution never really strong, and consumed from within by the ceaseless fires of its own overpowering and undying energy. On Tuesday, April the 18th, 1882, he was seized at midnight by violent pains, and at four o'clock on Wednesday afternoon he died suddenly in his son's arms, after a very short but painful illness. So retired was the family life at Down that the news of the great biologist's death was not actually known in London itself till two days after he had breathed his last.

The universal regret and grief expressed at the loss in all civilised countries was the best measure of the immense change of front which had slowly come over the whole educated community, in the twenty-three years since the first publication of the 'Origin of Species.' No sooner was Darwin's death announced than all lands and all classes vied with one another in their eagerness to honour the name and memory of the great biologist. Indeed, the spontaneous and immediate nature of the outburst of regret and affectionate regard which followed hard upon the news of Darwin's death, astonished even those who had watched closely the extraordinary revolution the man himself had brought so well to its final consummation. In England, it was felt instinctively on every side that the great naturalist's proper place was in the aisles of Westminster, hard by the tomb of Newton, his immortal predecessor. To this universal and deep-seated feeling Darwin's family regretfully sacrificed their own natural preference for a quiet interment in the graveyard at Down. On the Wednesday morning next after his death, Charles Darwin's remains were borne with unwonted marks, of respect and ceremony, in the assembled presence of all that was noble and good in Britain, to an honoured grave in the precincts of the great Abbey. Wallace and Huxley, Lubbock and Hooker, his nearest peers in the domain of pure science, stood among the bearers who held the pall. Lowell represented the republics of America and of letters. Statesmen, and poets, and philosophers, and theologians mingled with the throng of scientific thinkers who crowded close around the venerated bier. No incident of fitting pomp or dignity was wanting as the organ pealed out in solemn strains the special anthem composed for the occasion, to the appropriate words of the Hebrew poet, 'Happy is the man that findeth wisdom.' Even the narrow Philistine intelligence itself, which still knew Darwin only as the man who thought we were all descended from monkeys, was impressed with the sole standard of greatness open to its feeble and shallow comprehension by the mere solemnity and ceremony of the occasion, and began to enquire with blind wonderment what this thinker had done whom a whole people thus delighted to honour.

Of Darwin's pure and exalted moral nature no Englishman of the present generation can trust himself to speak with becoming moderation. His love of truth, his singleness of heart, his sincerity, his earnestness, his modesty, his candour, his absolute sinking of self and selfishness – these, indeed, are all conspicuous to every reader, on the very face of every word he ever printed. Like his works themselves, they must long outlive him. But his sympathetic kindliness, his ready generosity, the staunchness of his friendship, the width and depth and breadth of his affections, the manner in which 'he bore with those who blamed him unjustly without blaming them in return,' these things can never so well be known to any other generation of men as to the three generations who walked the world with him. Many even of those who did not know him loved him like a father; to many who never saw his face, the hope of winning Charles Darwin's approbation and regard was the highest incentive to thought and action. Towards younger men, especially, his unremitting kindness was always most noteworthy: he spoke and wrote to them, not like one of the masters in Israel, but like a fellow-worker and seeker after truth, interested in their interests, pleased at their successes, sympathetic with their failures, gentle to their mistakes. Not that he ever spared rightful criticism; on the contrary, the love of truth was with him so overpowering and enthralling a motive that he pointed out what seemed to him errors or misconceptions in the work of others with perfect frankness, fully expecting them to be as pleased and delighted at a suggested amendment of their faulty writing as he himself was in his own case. But his praise was as generous as his criticism was frank; and, amid all the toil of his laborious life in his study at Down, he could always find time to read and comment at full length upon whatever fresh contributions to his own subjects the merest tyro might venture to submit for his consideration. He had the sympathetic receptivity of all truly great minds, and when he died, thousands upon thousands who had never beheld his serene features and his fatherly eyes felt they had lost indeed a personal friend.

Greatness is not always joined with gentleness: in Charles Darwin's case, by universal consent of all who knew him, 'an intellect which had no superior' was wedded to 'a character even nobler than the intellect.'

CHAPTER XI

DARWIN'S PLACE IN THE EVOLUTIONARY MOVEMENT

To most people Darwinism and evolution mean one and the same thing. After what has here been said, however, with regard to the pre-Darwinian evolutionary movement, and the distinction between the doctrines of descent with modification and of natural selection, it need hardly be added that the two are quite separate and separable in thought, even within the limits of the purely restricted biological order. Darwinism is only a part of organic evolution; the theory, as a whole, owes much to Darwin, but it does not owe everything to him alone. There were biological evolutionists before ever he published the 'Origin of Species;' there are biological evolutionists even now who refuse to accept the truth of his great discovery, and who cling firmly to the primitive faith set forth in earlier and cruder shapes by Erasmus Darwin, by Lamarck, or by Robert Chambers.

Much more, then, must Darwinism and the entire theory of organic development to which it belongs be carefully discriminated, as a part or factor, from evolution at large, as a universal and all-embracing cosmical system. That system itself has gradually emerged as a slow growth of the past two centuries, a progressive development of the collective scientific and philosophical mind of humanity, not due in its totality to any one single commanding thinker, but summing itself up at last in our own time more fully in the person and teaching of Mr. Herbert Spencer than of any other solitary mouthpiece. Indeed, intimately as we all now associate the name of Darwin with the word 'evolution,' that term itself (whose vogue is almost entirely due to Mr. Spencer's influence) was one but rarely found upon Darwin's own lips, and but rarely written by his own pen. He speaks rather of development and of natural selection than of evolution: his own concern was more with its special aspect as biological modification than with its general aspect as cosmical unfolding. Let us ask, then, from this wider standpoint of a great and far-reaching mental revolution, what was Charles Darwin's exact niche in the evolutionary movement of the two last centuries?

Evolutionism, as now commonly understood, may be fairly regarded as a mode of envisaging to ourselves the history of the universe, a tendency or frame of mind, a temperament, one might almost say, or habit of thought rather than a definite creed or body of dogmas. The evolutionist looks out upon the cosmos as a continuous process unfolding itself in regular order in obedience to definite natural laws. He sees in it all, not a warring chaos restrained by the constant interference from without of a wise and beneficent external power, but a vast aggregate of original elements, perpetually working out their own fresh redistribution, in accordance with their own inherent energies. He regards the cosmos as an almost infinite collection of material atoms, animated by an almost infinite sum-total of energy, potential or kinetic.

In the very beginning, so far as the mental vision of the astronomer can dimly pierce with hypothetical glance the abyss of ages, the matter which now composes the material universe seems to have existed in a highly diffuse and nebulous condition. The gravitative force, however, with which every atom of the whole vast mass was primarily endowed, caused it gradually to aggregate around certain fixed and definite centres, which became in time the rallying-points or nuclei of future suns. The primitive potential energy of separation in the atoms of the mass was changed into actual energy of motion as they drew closer and closer together about the common centre, and into molecular energy or heat as they clashed with one another in bodily impact around the hardening core. Thus arose stars and suns, composed of fiery atomic clouds in a constant state of progressive concentration, ever gathering-in the hem of their outer robes on the surface of the solid globe within, and ever radiating off their store of associated energy to the impalpable and hypothetical surrounding ether. This, in necessarily brief and shadowy abstract, is the nebular theory of Kant and Laplace, as amended and supplemented by the modern doctrine of the correlation and conservation of energies.

Applied to the solar system, of which our own planet forms a component member, the evolutionary doctrine (in its elder shape) teaches us to envisage that minor group as the final result of a single great diffuse nebula, which once spread its faint and cloud-like mass with inconceivable tenuity, at least as far from its centre, now occupied by the sun's body, as the furthest point in the orbit of Neptune, the outermost of the yet known planets. From this remote and immense periphery it has gradually gathered itself in, growing denser and denser all the time, towards its common core, and has left behind, at irregular intervals, concentric rings or belts of nebulous matter, which, after rupturing at their weakest point, have hardened and concentrated round their own centre of gravity into Jupiter, Saturn, the Earth, or Venus. The main central body of all, retreating ever within as it dropped in its course the raw material of the planetary masses, has formed, at last, the sun, the great ruler and luminary of our system. Much as this primitive evolutionary concept of the development and history of the solar system has been modified and altered of late years by recent researches into the nature of comets and meteors and of the sun's surface, it still remains for all practical purposes of popular exposition the best and simplest mental picture of the general type of astronomical evolution. For the essential point which it impresses upon the mind is the idea of the planets in their several orbits and with their attendant satellites as due, not to external design and special creation, in the exact order in which we now see them, but to the slow and regular working out of preordained physical laws, in accordance with which they have each naturally assumed, by pure force of circumstances, their existing size, and weight, and orbit, and position.

Geology has applied a similar conception to the origin and becoming of the earth's material and external features as we now know them. Accepting from astronomy the notion of our planet's primary condition as a cooling sphere of incandescent matter, it goes on to show how the two great envelopes, atmospheric and oceanic, gaseous and liquid, have gradually formed around its solid core; how the hard crust of the central mass has been wrinkled and corrugated into mountain chain and deep-cut valley, uplifted here into elevated table-land or there depressed into hollow ocean bed; how sediment has slowly gathered on the floor of the sea, and how volcanic energies or lateral pressure have subsequently forced up the resulting deposits into Alpine peaks and massive continents. In this direction, it was Lyell who principally introduced into science the uniformitarian or evolutionary principle, who substituted for the frequent cataclysms and fresh beginnings of the earlier geologists the grand conception of continuous action, producing from comparatively infinitesimal but cumulative causes effects which at last attain by accretion the most colossal proportions.

Here biology next steps in, with its splendid explanation of organic life, as due essentially to the secondary action of radiated solar energy on the outer crust of such a cooling and evolving planet. Falling on the cells of the simplest green plants, the potent sunlight dissociates the carbon from the oxygen in the carbonic acid floating in the atmosphere, and builds it up with the hydrogen of water in the tissues of the organism into starches and other organic products, which differ from the inert substances around them, mainly by the possession of locked-up solar energy. On the energy-yielding food-stuffs thus stored up the animal in turn feeds and battens, reducing what was before potential into actual motion, just as the steam-engine reduces the latent solar energy of coal into visible heat and visible movement in its furnace and its machinery. How the first organism came to exist biology has not yet been able fully to explain for us; but aided by chemical science it has been able to show us in part how some of the simpler organic bodies may have been originally built up, and it does not despair of showing us in the end how the earliest organism may actually have been produced from the prime elements of oxygen, hydrogen, nitrogen, and carbon. Into this most fundamental of biological problems, however, Darwin himself, with his constitutional caution and dread of speculative theorising, was not careful or curious to enter. Even upon the far less abstruse and hypothetical question, whether all life took its prime origin from a single starting-point or from several distinct and separate tribal ancestors, he hardly cared so much as to hazard a passing speculation. With splendid self-restraint he confined his attention almost entirely to the more manageable and practical problem of the origin of species by natural selection, which lay then and there open for solution before him. Taking for granted the existence of the original organism or group of organisms, the fact of reproduction, and the tendency of such reproduction to beget increase in a geometrical ratio, he deduced from these elementary given factors the necessary corollary of survival of the fittest, with all its marvellous and far-reaching implications of adaptation to the environment and specific distinctions. By doing so, he rendered conceivable the mechanism of evolution in the organic world, thus bringing another great aspect of external nature within the range of the developmental as opposed to the miraculous philosophy of the cosmos.

Psychology, once more, in the hands of Herbert Spencer and his followers, not wholly unaided by Darwin himself, has extended the self-same evolutionary treatment to the involved and elusive phenomena of mind, and has shown how from the simplest unorganised elements of feeling, the various mental powers and faculties as we now know them, both on the intellectual and on the emotional side, have been slowly built up in the long and ever-varying interaction between the sentient organism and the natural environment. It has traced the first faint inception of a nervous system as a mere customary channel of communication between part and part; the gradual growth of fibre and ganglion; the vague beginnings of external sense-organ and internal brain; the final perfection of eye and ear, of sight and hearing, of pleasure and pain, of intellect and volition. It has thus done for the subjective or mental half of our complex nature what biology, as conceived by Darwin, has done for the physical or purely organic half; it has traced the origin and development of mind, without a single break, from its first faint and half-unconscious manifestation in the polyp or the jelly-fish to its final grand and varied outcome in the soul of the poet or the intellect of the philosopher.

Finally, sociology has applied the evolutionary method to the origin and rise of human societies, with their languages, customs, arts, and institutions, their governmental organisation and their ecclesiastical polity. Taking from biology the evolving savage, viewed as a developed and highly gifted product of the anthropoid stock, it has shown by what stages and through what causes he has slowly aggregated into tribes and nations; has built up his communal, polygamic, or monogamic family; has learnt the use of fire, of implements, of pottery, of metals; has developed the whole resources of oral speech and significant gesture; has invented writing, pictorial or alphabetic; has grown up to science, to philosophy, to morals, and to religion. The chief honours of this particular line of enquiry, the latest and youngest of all to receive the impact of the evolutionary impulse, belong mainly to Tylor, Lubbock, and Spencer in England, and to Haeckel, De Mortillet, and Wagner on the continent.

In the sublime conception of the external universe and its present workings which we thus owe to the independent efforts of so many great progressive thinkers, and which has here been briefly and inadequately sketched out, Darwin's work in life falls naturally into its own place as the principal contribution to the evolutionary movement in the special biological department of thought. Within the more limited range of that department itself, the evolutionary impulse did not owe its origin to Charles Darwin personally; it took its rise with Erasmus Darwin, Buffon, and Lamarck, and it derived from our great modern English naturalist its final explanation and definitive proof alone. But just as the evolutionary movement in astronomy and cosmical thought is rightly associated in all our minds with the mighty theories of Kant, Laplace, and Herschel; just as the evolutionary movement in geology is rightly associated with the far lesser yet brilliant and effective personality of Lyell; just as the evolutionary movement in the derivative sciences is rightly associated with so many great still living thinkers; so the evolutionary movement in biology in particular rightly sums itself up in the honoured name of Charles Darwin. For what others suspected, he was the first to prove; where others speculated, he was the first to observe, to experiment, to demonstrate, and to convince.

It should be noted, too, that while to us who come after, the great complex evolutionary movement of the two last centuries justly reveals itself as one and indivisible, a single grand cosmical drama, having many acts and many scenes, but all alike inspired by one informing and pervading unity, yet to those whose half unconscious co-operation slowly built it up by episodes, piecemeal, each act and each scene unrolled itself separately as an end in itself, to be then and there attained and proved, quite apart from the conception of its analytic value as a part in a great harmonious natural poem of the constitution of things. Though evolution appears to us now as a single grand continuous process, a phase of the universe dependent upon a preponderating aggregation of matter and dissipation of energy, yet to Kant and Laplace it was the astronomical aspect alone that proved attractive, to Darwin it was the biological aspect alone, and to many of the modern workers in the minor fields it is the human and sociological aspect that almost monopolises the whole wide mental horizon. No greater proof can be given of the subjective distinctness of parts in what was objectively and fundamentally a single broad psychological revolution of the human mind, than the fact that Lyell himself, who more than any one man had introduced the evolutionary conception into the treatment of geology, should have stood out so long and fought so blindly against the evolutionary conception in the organic world. Indeed, it was not until the various scattered and many-coloured strands of evolutionary thought had been gathered together and woven into one by the vast catholic and synthetic intelligence of Herbert Spencer that the idea of evolution as a whole, as a single continuous cosmical process, began to be apprehended and gradually assimilated by the picked intelligences of the several distinct scientific departments.

Observe also that the evolutionary method has invaded each of the concrete sciences in the exact order of their natural place in the hierarchy of knowledge. It had been applied to astronomy by Kant and Laplace before it was applied to geology by Lyell; it had been applied to geology by Lyell before it was applied to biology by Darwin; it had been applied to biology (in part, at least) by Lamarck and the Darwins before it was applied to psychology by Spencer; and it is only at the very end of all that it has been applied to sociology and the allied branches of thought by a hundred different earnest workers in contemporary Europe. Each stage helped on the next; each was dependent only on those that went naturally before it, and aided in turn the subsequent development of those that naturally came after it.

Nevertheless, the popular instinct which regards Darwinism and evolution as practically synonymous is to a large extent justified by the actual facts of the psychological upheaval. Darwin's work forms on the whole the central keystone of the evolutionary system, and deserves the honour which has been thrust upon it of supporting by its own mass the entire superstructure of the development theory.

For, in the first place, Darwin had to deal with the science of life, the science where the opposition to evolutionism was sure to be strongest, and where the forces and tendencies in favour of obscurantism were sure to gather in fullest force. Every other great onward step in our knowledge of our own relation to the universe of which we form a part had been compelled indeed to run the gauntlet, in its own time, of ecclesiastical censure and of popular dislike. Those inveterate prejudices of human ignorance which sedulously hide their genuine shape under the guise of dogma masquerading as religion, had long since brought to bear their baneful resources upon the discoveries of Copernicus and the theories of Galileo, as blind, misleading, and diabolical lights, opposed to the sure and certain warranty of Holy Scripture. Newton, again, had in due time been blamed in that he boldly substituted (as his critics declared) the bald and barren formula of gravitation for the personal superintendence of a divine Providence. Laplace had been accused of dethroning the deity from the centre and governance of his celestial system. Around the early geologists the battle of the six days of creation had raged fiercely for nearly half a century. But all these varying modes of thought, though deemed heretical enough in their own day, had touched, as it were, but the minor ramparts and unimportant out-works of the great obscurantist dogmatic strongholds: Darwinism, by openly attacking the inmost problems of life and mind, had brought to bear its powerful artillery upon the very keep and highest tower of the fortress itself. The belief that the various stars, planets, and satellites had or had not been wisely created in their existing positions, and with their present orbits, movements, and relations accurately fore-measured, did not fundamentally affect, for good or evil, the cherished dogmas of the ordinary multitude. But the analogous belief in the distinct and separate creation of plants and animals, and more especially of the human species, was far more closely and intimately bound up with all the current religious conceptions. It was at first supposed, not perhaps without some practical wisdom, that to upset the primitive faith in the separate creation of living beings was to loosen and imperil the very foundations of common morality and revealed religion. The 'argument from design' had been immemorially regarded as the principal buttress of orthodox thought. Theologians had unwisely staked their all upon the teleological dogma, and could ill afford to retire without a blow from that tenaciously defended bastion of their main position. Hence the evolutionary concept had its hardest fight to wage over the biological field; and when that field was once fairly won, it had little more to fear from banded preconceptions and established prejudices in any other portion of the wide territory it claimed for its own.

In the second place, biological evolution, firmly established by Darwin on a safe, certain, and unimpeachable basis, led naturally and almost inevitably to all the other innumerable applications of the evolutionary method, in the domains of psychology, sociology, philology, political thought, and ethical science. Hence the immediate and visible results of its promulgation have been far more striking, noticeable, and evident than those which followed the establishment of the evolutionary conception in the astronomical and geological departments. It was possible to accept cosmical evolution and solar evolution and planetary evolution, without at the same time accepting evolution in the restricted field of life and mind. But it was impossible to accept evolution in biology without at the same time extending its application to psychology, to the social organism, to language, to ethics, to all the thousand and one varied interests of human life and human development. Now, most people are little moved by speculations and hypotheses as to the origin of the milky way or the belt of Orion; they care very slightly for Jupiter's moons or Saturn's rings; they are stolidly incurious as to the development of the earth's crust, or the precise date of the cretaceous epoch; but they understand and begin to be touched the moment you come to the practical questions of man's origin, nature, and history. Darwinism compelled their attention by its immediate connection with their own race; and the proof of this truth is amply shown by the mere fact that out of all the immense variety of Charles Darwin's theories and ideas, the solitary one which alone has succeeded in attaching to itself the public interest and public ridicule is the theory of man's ultimate descent from a monkey-like ancestor. Popular instinct, here as elsewhere profoundly true at core in the midst of all its superficial foolishness, has rightly hit upon the central element in the Darwinian conception which more than any other has caused its fruitful and wonderful expansion through every fertile field of human enquiry.

In short, it was Darwin's task in life to draw down evolution from heaven to earth, and to bring within the scope of its luminous method all that is most interesting to the uninstructed and unsophisticated heart of the natural man.

The application of the evolutionary principle to the world of life, human or animal, thus presents itself as the chief philosophic and scientific achievement of the nineteenth century. Throughout the whole middle decades of the present age, the human mind in all its highest embodiments was eagerly searching, groping, and enquiring after a naturalistic explanation of the origin and progress of organic life. In the vast scheme for the System of Synthetic Philosophy which Herbert Spencer set forth as an anticipatory synopsis of his projected work, the philosopher of development leapt at once from the First Principles of evolution as a whole to the Principles of Biology, Psychology, and Sociology, omitting all reference to the application of evolution to the vast field of inorganic nature; and he did so on the distinctly stated ground that its application to organic nature was then and there more important and interesting. That suggestive expression of belief aptly sums up the general attitude of scientific and philosophic minds at the precise moment of the advent of Darwinism. Kant and Laplace and Lyell had already applied the evolutionary method to suns and systems, to planets and continents; what was needed next was that some deeply learned and universally equipped biological leader should help the lame evolutionism of Lamarck over the organic stile, and leave it free to roam the boundless fields of what Mr. Spencer has sometimes well described as the super-organic sciences. For that office, Darwin at the exact moment presented himself; and his victory and its results rightly entitle him to the popular regard as the founder of all that most men mean when they speak together in everyday conversation of the doctrine of evolution.

On the other hand, the total esoteric philosophic conception of evolution as a cosmical process, one and continuous from nebula to man, from star to soul, from atom to society, we owe rather to the other great prophet of the evolutionary creed, Herbert Spencer, whose name will ever be equally remembered side by side with his mighty peer's, in a place of high collateral glory. It is he who has given us the general definition of evolution as a progress from an indefinite, incoherent homogeneity to a definite coherent heterogeneity, accompanying an integration of matter and dissipation of motion, or, as we should now perhaps more correctly say, of energy. In the establishment of the various lines of thought which merge at last in that magnificent cosmical law, it was Darwin's special task to bring the phenomena of organic life well within the clear ken of known and invariable natural processes.

CHAPTER XII

THE NET RESULT

And now let us ask ourselves, in all sincerity, what was the final outcome and net result of Darwin's great and useful life?

If Charles Darwin had never existed at all, there would still have been a considerable and expansive evolutionary movement both in biology and in its sister sciences throughout the latter half of the present century. The harvest indeed was ready, and the labourers, though few, were full of vigour. Suppose for a moment that that earnest and single-hearted Darwinian genius had been cut off by some untimely disease of childhood at five years old, all other conditions remaining as they were, we should even so have had in our midst to-day, a small philosophical and influential band of evolutionary workers. Spencer would none the less have given us his 'First Principles' and the major part of his 'Principles of Biology,' with comparatively little alteration or omission. Wallace would none the less have promulgated his inchoate theory of natural selection, and rallied round his primordial conception the very best and deepest minds of the biological fraction. Geology would have enforced the continuity of types; Cope and Marsh would have unearthed for our edification the ancestral forms of the evolving horse and the toothed birds of the Western American deposits. The Solenhofen lithographic slates would still have yielded us the half-reptilian, half-avian Archæopteryx; the tertiary deposits would still have presented us with a long suite of gradually specialised and modified mammalian forms. The Siberian meadows would have sent us that intermediate creature which Prjevalsky recognises as the half-way house between the horses and the donkeys; the rivers of Queensland would have disclosed to our view that strange lung-bearing and gill-breathing barramunda, in which Günther discerns the missing link between the ganoid fishes on the one hand, and the mudfish and salamandroid amphibians on the other. From data such as these, biologists and palæontologists of the calibre of Huxley, Gaudry, Geikie, Rütimeyer, and Busk, would necessarily have derived, by the aid of Wallace's pregnant principle, conclusions not so very far remote from Darwin's own. Heer and Saporta would have drawn somewhat similar inferences from the fossil flora of Switzerland and of Greenland; Hooker and De Candolle would have read pretty much the self-same lessons in the scattered ferns and scanty palm-trees of oceanic islands. Kowalevsky would have seen in the ascidian larva a common prototype of the vertebrate series; the followers of Von Baer would have popularised the embryological conception of the single origin of animal life. The researches of Boucher de Perthes, of Lyell, of Evans, of Boyd Dawkins, of Keller, and of Christy and Lartet, would have unrolled before our eyes, under any circumstances, the strange story of prehistoric man. On the facts so gained, Lubbock and Tylor, Schaafhausen and Büchner, would have built up their various consistent theories of human development and human culture. In short, even without Charles Darwin, the nineteenth century would not have stood still; it would have followed in the wake of Buffon and Diderot, of Lamarck and Laplace, of St. Hilaire and Goethe, of Kant and Herschel, of Hutton and Lyell, of Malthus and of Spencer. The great world never rolls down the abysses of time obedient to the nod of one single overruling Titanic intellect. 'If the doctrine of evolution had not existed,' says Huxley, 'palæontologists must have invented it.'

But Charles Darwin acted, nevertheless, the part of an immense and powerful accelerating energy. The impetus which he gave gained us at least fifty years of progress; it sent us at a bound from Copernicus to Newton; so far as ordinary minds were concerned, indeed, it transcended at a single leap the whole interval from Ptolemy to Herschel. The comparison is far from being a mere rhetorical one. A close analogy really exists between the two cases. Before Copernicus, the earth stood fixed and immovable in the centre of the universe, with obsequious suns, and planets, and satellites dancing attendance in cycle and epicycle around the solid mass, to which by day and night they continually ministered. The great astronomical revolution begun by Copernicus, Galileo, and Kepler, and completed by Newton, Laplace, and Herschel, reduced the earth to its true position as a petty planet, revolving feebly among its bigger brethren round a petty sun, in some lost corner of a vast, majestic, and almost illimitable galaxy. Even so, before Darwin, man stood in his own esteem the fixed point of an anthropocentric universe, divinely born and divinely instructed, with all the beasts of the field, and the fowls of the air, and the fruits of the earth specially created with a definite purpose in subservience to his lordly wants and interests. The great biological revolution, which rightly almost sums itself up in the name of Darwin, reduced man at once to his true position as the last product of kinetic solar energy, working upon the peculiar chemical elements of an evolving planet. It showed that every part of every plant and every animal existed primarily for the sake of that plant or animal alone; it unseated man from his imaginary throne in the centre of the cosmos, teaching him at once a lesson of humility and a lesson of aspiration – pointing out to him how low was the origin from which, in very truth, he first sprang, and suggesting to him, at the same time, how high was the grand and glorious destiny to which by his own strenuous and ardent efforts he might yet perchance some day attain.