No doubt some impulse to Darwin's views in this direction 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, all in 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, influenced Darwin, 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,[7] and after a time perceived that man's power of selecting and breeding from certain individuals was the most powerful of all means in the production of new races. Having attended to the habits of animals, and their relations to the surrounding conditions, I was able to 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 in The Leader in 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 Novae Zelandiae," dated November, 1853, in which he discusses among other questions, "The Limits of Species; their Dispersion and Variation." 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 Laws which affect the Production of Varieties, Races, and Species,' contain the results of the investigations of two indefatigable naturalists, Mr. Charles Darwin and Mr. Alfred Wallace.

"These gentlemen having, independently and unknown to one another, conceived the same very ingenious theory to account for the appearance and perpetuation of varieties and of specific forms on our planet, may both fairly claim the merit of being original thinkers in this important line of inquiry; but neither of them having published his views, though Mr. Darwin has 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 the leading 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 Tasmaniae," 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.

FOOTNOTES:

[6: It is worth while to reproduce here a few sentences from Erasmus Darwin's "Zoonomia," showing how acutely he guessed in the direction of evolution.

"When we revolve in our minds, first, the great changes which we see naturally produced in animals after their nativity.... Secondly, when we think over the great changes introduced into various animals by artificial or accidental cultivation.... Thirdly, when we enumerate the great changes produced in the species of animals before their nativity.... Fourthly, when we revolve in our minds the great similarity of structure which obtains in all the warm-blooded animals.... Fifthly, from their first rudiment or primordium to the termination of their lives, all animals undergo perpetual transformations, which are in part produced by their own exertions;... and many of these acquired forms or propensities are transmitted to their posterity.... A great want of one part of the animal world has consisted in the desire of the exclusive possession of the female; and these have acquired weapons to combat each other for this purpose.... The final cause of this contest amongst the males seems to be that the strongest and most active animal should propagate the species, which should thence become improved. Another great want consists in the means of procuring food, which has diversified the forms of all species of animals.... All which seem to have been gradually produced during many generations by the perpetual endeavour of the creatures to supply the want of food, and to have been delivered to their posterity with constant improvement of them for the purpose required.... The third great want among animals is that of security, which seems much to have diversified the forms of their bodies and the colour of them.... The contrivances for the purposes of security extend even to vegetables.... Would it be too bold to imagine that in the great length of time since the earth began to exist ... all warm-blooded animals have arisen from one living filament, which the Great First Cause endued with animality;... possessing the faculty of continuing to improve by its own inherent activity, and of delivering down those improvements by generation to its posterity, world without end!"]

[7: In this study Darwin came into communication, as early as 1839, with the Hon. and Rev. W. Herbert, afterwards Dean of Manchester, and received from him a personal account of his experiments on hybrids. It was Herbert who, as early as 1822, in the fourth volume of the "Horticultural Transactions," and in his work on the Amaryllidaceae, 1837, declared that horticultural experiments have established, beyond the possibility of refutation, that botanical species are only "a higher and more permanent class of varieties." He extended the same view to animals, and believed that single species of each genus were originally created in a highly plastic condition, and that these have produced, chiefly by intercrossing, but also by variation, all our existing species.]

[8: The first portion of this important letter is quoted from the English translation of Haeckel's "History of Creation," 1876; the second portion from O. Schmidt's "Doctrine of Descent and Darwinism," having been re-written by Darwin from the German text.]



CHAPTER V.

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 shown how species 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 by the 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 3000 B.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 as perfect 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 a dozen 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 down by 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 should plainly 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 largely speaks 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 from fatal 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 of structure 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 pupae 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 pupae 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, was closely 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 is most 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 larvae of ichneumonidae 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. It is far 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, and on 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 solely by 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 that The Athenaeum (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 Review considered 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 and Races 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 in The 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]

The Saturday Review was much more moderate, by no means sharing the anxiety of those who regarded evolutionary theories as hostile to Christianity. The author is said to have encountered the difficulties of his theory "with admirable skill and ability," and though The Saturday remained unconvinced of his general argument, yet it acknowledged itself "persuaded that natural selection must henceforward be admitted as the chief mode by which the structure of organised beings is modified in a state of nature;" and thought it very possible that, through its agency, considerable groups of nearly allied species might have been derived from a single progenitor: but there The Saturday stopped, believing in limits to this power.

The second edition of "The Origin of Species," which appeared in January, 1860, only six weeks after the first, contained but few alterations; the third, in March, 1861, had received extensive additions and corrections. The most important of these discussed the so-called tendency of organisation to advance, and explained the present coexistence of high and lowly organised forms. A valuable historical sketch of the modern progress of opinion on the subject, from Lamarck's time, was prefixed to the book. It was further enlarged in subsequent editions, as evidences accumulated that various thinkers had independently adopted the evolution theory, or the more special one of natural selection. Notable instances of anticipation were those of Dr. Wells, who, in a paper read before the Royal Society in 1813, but not published till 1818, had expressed the opinion that all animals tend to vary; that agriculturists improve breeds by selection; and that what they do by art "seems to be done with equal efficacy, though more slowly, by nature, in the formation of varieties of mankind." He then goes on to exemplify the survival of the fittest, though in other words. Mr. Patrick Matthew, in 1831, published a work on "Naval Timber and Arboriculture," in which he expressed, in scattered passages, a view nearly resembling Darwin's.

The fourth edition of "The Origin," in 1866, was longer, by fifty pages, than its predecessor. Among the additions may be mentioned a fuller treatment of the argument from embryology, which was made stronger by later investigations. The fifth edition (1869) was comparatively little increased in bulk, though altered in many details. In particular it contained a somewhat important change relating to the extent of the influence of natural selection. This is also referred to in "The Descent of Man" (first edition, vol. i. pp. 152-3), where the author says he had not formerly considered sufficiently the existence of many structures which appeared to be neither beneficial nor injurious, and had attributed too much to natural selection. "I was not able," he says, "to annul the influence of my former belief, then widely prevalent, that each species had been purposely created; and this led to my tacitly assuming that every detail of structure, excepting rudiments, was of some special, though unrecognised, service.... If I have erred in giving to natural selection great power, which I am far from admitting, or in having exaggerated its power, which is in itself probable, I have, at least, as I hope, done good service in aiding to overthrow the dogma of separate creations."

The sixth edition (1872), in smaller type, was considerably revised and altered, and remains permanent. A glossary of scientific terms was added by Mr. W. S. Dallas. A new chapter was inserted after the sixth, and entitled "Miscellaneous Objections to the Theory of Natural Selection." It was partly derived from modified portions of chapter iv. of former editions, but the latter and larger part was new, and relates chiefly to the supposed incompetency of natural selection to account for the very early stages of useful structures. Numerous cases, such as the development of the giraffe's neck, the baleen of the whale, the mammary glands, &c., are admirably discussed. Causes preventing the acquisition, through natural selection, of useful structures in many cases are dealt with, and reasons given for disbelieving in great and sudden modifications. In the concluding chapter Darwin further admits that he had formerly underrated the frequency and importance of use and disuse of parts, of the direct action of external conditions, and of variations which seem to us, in our ignorance, to arise spontaneously. He alludes to misrepresentations of his views, and calls attention to the fact that, in the first edition, at the close of the introduction, he stated his conviction that natural selection had been the main, but not the exclusive means of modification. "This has been of no avail. Great is the power of steady misrepresentation; but the history of science shows that, fortunately, this power does not long endure." This is Darwin's almost sole allusion in his works to the persistence with which views not his had been attributed to him, or he had been calumniated for views he did hold. But in his own lifetime—nay, within fifteen years—he witnessed a sufficiently satisfying revolution. "I formerly spoke to very many naturalists on the subject of evolution, and never once met with any sympathetic agreement. It is probable that some did then believe in evolution, but they were either silent or expressed themselves so ambiguously, that it was not easy to understand their meaning. Now things are wholly changed, and almost every naturalist admits the great principle of evolution" ("Origin," sixth edition, p. 424). At present the sale of the book in this country approaches forty thousand copies. Its sale in America has been very large; and numerous translations into German, French, Italian, Russian, Dutch, and Swedish, and even into Japanese and Hindustani, have been largely sold. It must always be one of the most valued of all English classics.

FOOTNOTES:

[9: Mr. Romanes, in his paper on "Physiological Selection" (Journal of the Linnean Society, Zoology, xix. 337-411), has entered upon a most important discussion of this question.]

[10: The full text of a large part of Darwin's original chapter on Instinct, which was omitted from the "Origin of Species" for the sake of condensation, is published in Mr. Romanes' "Mental Evolution in Animals," 1883, which also contains many other observations by Darwin.]

[11: The reader will thus be able to judge for himself how far Darwin's "Origin of Species" gained, "from the very first outset, universal respect and a fair hearing," as Mr. Grant Allen, with singular forgetfulness, states ("Darwin," p. 112). The violence of the attacks made upon Darwin by the majority of religious and orthodox journals is well known.]



CHAPTER VI.

We have already gathered much concerning Darwin's mental and moral fibre in our survey of his works. Let us make some further acquaintance with his personality as known to his friends. Outwardly he appeared a man of powerful physique, standing six feet high, with prominent forehead and over-arching brow, and keen, deep-set eyes in which resolute strength and piercing insight were indicated. Apart from his persistent infirmity, he was actively disposed, as indeed is evident from the laborious journeys he undertook during his travels. Field sports, including hunting, were among the recreations of his more active years. But through all his work or recreation the imperious conditions necessitated by his infirmity of stomach had to be considered, and nothing but the most rigorous care could possibly have enabled him to achieve what he did. On many days he could not work at all, and on many others two or three hours were his limit. And what but his own system, his own orderliness and perseverance could have accomplished his task? In preparing his books he had a special set of shelves for each, standing on or near his writing-table, one shelf for each chapter. The maxim, "Early to bed, and early to rise," was his essentially, and regularity kept all balanced. Rising at six, he took a cold plunge bath, breakfasted simply, and took a first walk, beginning work often at eight. "Later in the day," I quote from Mr. Woodall's pleasant pages, "he generally walked again, often in his own grounds, but sometimes further afield, and then generally by quiet footpaths rather than frequented roads. The walks at one time were varied by rides along the lanes on a favourite black cob, but some years before his death his four-footed friend fell, and died by the roadside, and from that day the habit of riding was given up. Part of the evening was devoted to his family and his friends, who delighted to gather round him to enjoy the charm of his bright intelligence, and his unrivalled stores of knowledge. To Down, occasionally, came distinguished men from many lands; and there in later years would sometimes be found the younger generation of scientific students, looking up to the great naturalist with the reverence of disciples, who had experienced his singular modesty, his patient readiness to listen to all opinions, and the winning grace with which he informed their ignorance and corrected their mistakes. In the midst of all the delights of home and the demands of study, Darwin kept an open mind for public affairs. He united the earnest politician with the patient student: a rare combination, which supplies another proof of his largeness of heart and sympathy with his fellow men. In the village of Down he was liked by everybody, old and young, and in his own household the same servants lived year after year under his roof. One of them, Margaret Evans, who assisted in nursing him in his last illness, had come to Down nearly forty years before, from Shrewsbury, where her uncle and aunt were in Dr. Darwin's service."

At Down the family in time numbered nine children, two, however, not surviving childhood; one died in 1842, another in 1858. His five sons have already attained distinction or positions of influence. The eldest, William Erasmus, became a banker in Southampton; the second, George, was second Wrangler and Smith's Prizeman at Cambridge in 1868, became a Fellow of Trinity, and is now Plumian Professor of Astronomy at his university, having early gained the Fellowship of the Royal Society for his original papers bearing on the evolution of the universe and the solar system, and many other subjects of high mathematical and philosophical interest. His third son, Francis, gained first-class honours in the Cambridge Natural Science Tripos in 1870, and is likewise a Fellow of the Royal Society, in recognition of his original botanical investigations. The fourth, Leonard, an officer in the Royal Engineers, has done valuable astronomical work. The fifth, Horace, has devoted himself to mechanical science, and has largely aided in developing the Cambridge Scientific Instrument Company.

The great thinker, fulfilling his duties as head of a family with singular success, charged with the burden of new thoughts and observations, slowly perfecting his life work, had neither time nor inclination for controversy. He set himself to publish facts, which by their accumulation tended to clench his arguments. Soon after the "Origin of Species" he had in course of publication several important botanical papers, on the two forms of flower in the Primrose genus (1862), and in the genus Linum (flax), 1863, on the forms of Loosestrife, 1864, all published in the Linnean Society's Journal.

In 1862 he brought out his first botanical book, the "Fertilisation of Orchids," more fully entitled, "On the various Contrivances by which Orchids are Fertilised by Insects." These most singular flowers had long attracted great attention owing to their peculiar shapes and often their great beauty, while their marked deviation from typical forms of flowers perplexed botanists extremely. The celebrated Robert Brown, in a well-known paper in the Linnean Society's Transactions, 1833, expressed the belief that insects are necessary for the fructification of most orchids; and as far back as 1793, Christian Sprengel (in "The Newly Discovered Secret of Nature") gave an excellent account of the action of the several parts in the genus Orchis, having discovered that insects were necessary to remove the pollen masses. But the rationale of the process was not fully known until Darwin revealed it, and illuminated it by the light of natural selection. He had, in the "Origin of Species," given reasons for the belief that it is an almost universal law of nature that the higher organic beings require an occasional cross with another individual. He here emphasised that doctrine by a series of proofs from a peculiar and otherwise inexplicable order of plants, and showed that the arrangements by which orchids are fertilised have for their main object the fertilisation of the flowers with pollen brought by insects from a distinct plant.

In the group to which our common orchids belong, remarkable adaptations for securing that the pollen masses brought from another flower solely through the visits of insects shall reach their precise destination, were brought to light. "A poet," says Darwin, "might imagine that whilst the pollinia were borne through the air from flower to flower, adhering to an insect's body, they voluntarily and eagerly placed themselves in that exact position in which alone they could hope to gain their wish and perpetuate their race." As he had examined all the British genera, Darwin's conclusions were indubitable. He had patiently watched for hours on the grass to notice insects' visits, had counted the fertilised flowers on many spikes, the fertilised spikes on many plants, had dissected and redissected the flowers till he saw how the fertilisation must absolutely be effected; and utilising the enthusiasm of orchid growers, had excited them to do the same, till his storehouse of facts was full.

On examining the exotic forms of orchids, which are so conspicuous in our conservatories, still more striking facts presented themselves. In the great group of the Vandeae, relative position of parts, friction, viscidity, elastic and hygrometric movements were all found to be nicely related to one end—the aid of insects in fertilisation. Without their aid not a plant in the various species of twenty-nine genera which Darwin examined would set a seed. In the majority of cases insects withdraw the pollen masses only when retreating from the flower, and, continuing their flower visits, effect a union between two flowers, generally on distinct plants. In many cases the pollen masses slowly change their position while adhering to the insects, and so assume a proper direction for striking the stigma of another flower, and the insects during this interval will almost certainly have flown from one plant to another.

The family to which Catasetum belongs furnished the most remarkable examples. This plant possesses a special sensitiveness in certain parts, and when definite points of the flower are touched by an insect the pollen masses are shot forth like an arrow, the point being blunt and adhesive. The insect, disturbed by so sharp a blow, or having eaten its fill, flies sooner or later to a female plant, and whilst standing in the same position as before, the pollen-bearing end of the arrow is inserted into the stigmatic cavity, and a mass of pollen is left on its viscid surface. The strange structures of Cypripedium, or the Lady's Slipper, were then analysed, and the mode of fertilisation by small bees was discovered. The whole structure of orchids, as modified to secure insects' visits and cross fertilisation, was now expounded, and the benefits shown by cases where insects' visits were prevented, and no seed was set. The number of seeds in a capsule was reckoned, and thence it was found that the progeny of a single plant of the common orchis would suffice to cover the globe in the fourth generation. A single plant of another orchid might bear seventy-four millions of seeds: surely an ample provision for a struggle for existence, and selection and survival of the fittest. But, as Darwin remarks, profuse expenditure is nothing unusual in nature, and it appears to be more profitable for a plant to yield a few cross-fertilised than many self-fertilised seeds.

Darwin impresses forcibly on his readers the endless diversity of structures, and the prodigality of resources displayed for gaining the same end, the fertilisation of one flower by pollen from another plant. "The more I study nature," he says, "the more I become impressed with ever-increasing force that the contrivances and beautiful adaptations slowly acquired through each part occasionally varying in a slight degree ... transcend in an incomparable manner the contrivances and adaptations which the most fertile imagination of man could invent." Finally he concludes: "It is hardly an exaggeration to say that nature tells us, in the most emphatic manner, that she abhors perpetual self-fertilisation"; and thus was announced a new doctrine in botany. A second much-improved edition of this book appeared in 1877.

In 1864, in presenting the Copley medal of the Royal Society to the author of the "Origin of Species," Major-General Sabine, the President, entered into a full description of the merits of his works, "stamped throughout with the impress of the closest attention to minute details and accuracy of observation, combined with large powers of generalisation." The award, while highly eulogising the "Origin," was not however based upon it, but on the more recent botanical writings. "The Fertilisation of Orchids" was described as perhaps the most masterly treatise on any branch of vegetable physiology that had ever appeared; and the fact was justly emphasised that all Darwin's botanical discoveries had been obtained by the study of some of the most familiar and conspicuous of our native plants, and some of the best-known and easily-procured cultivated exotics.

In 1865 appeared another work from the Darwinian treasury, but in this case it was at first restricted to the Journal of the Linnean Society (vol. ix.), and was not made generally available till the second edition was published separately in 1875. "The Movements and Habits of Climbing Plants" described in the first place the twining of the hop plant, studied by night and day continuously, in a well-warmed room, to which the author was confined by illness. Again and again were different species of plants watched, and the periods in which their shoots revolved noted. The clematises, tropaeolums, solanums, gloriosa lilies among leaf-climbing plants; the bignonias, cobaeas, bryonies, vines, passion flowers, and other tendril-bearing plants; the ivy, and other root and hook climbers were carefully studied; and botanists for the first time realised fully the advantages which climbing plants possess in the struggle for existence. The climbing faculty depends on a sensitiveness to contact with any firm support, and a most interesting series of modifications has probably, as Darwin suggests, led to the present development of climbing organs, by the spontaneous movement of young shoots and other organs, and by unequal growth.

In concluding, the author made some most profoundly suggestive remarks, which went far to revolutionise our conception of plants. "It has often been vaguely asserted that plants are distinguished from animals by not having the power of movement. It should rather be said that plants acquire and display this power only when it is of some advantage to them; this being of comparatively rare occurrence, as they are affixed to the ground, and food is brought to them by the air and rain. We see how high in the scale of organisation a plant may rise, when we look at one of the more perfect tendril-bearers. It first places its tendrils ready for action, as a polypus places its tentacula. If the tendril be displaced, it is acted on by the force of gravity, and rights itself. It is acted on by the light, and bends towards or from it, or disregards it, which ever may be most advantageous. During several days the tendrils, or internodes, or both, spontaneously revolve with a steady motion. The tendril strikes some object, and quickly curls round and firmly grasps it. In the course of some hours it contracts into a spire, dragging up the stem, and forming an excellent spring. All movements now cease. By growth the tissues soon become wonderfully strong and durable. The tendril has done its work, and has done it in an admirable manner."

The labour of revising the successive editions of the "Origin of Species," together with prolonged ill-health, delayed the fulfilment of the promise given in that work, that the facts upon which it was based should be published. It was not till 1868 that the first instalment, "The Variation of Animals and Plants under Domestication," was given to the world, in two large volumes, with numerous illustrations. The author's design was to discuss in a second work the variability of organic beings in a state of nature, and the conversion of varieties into species, the struggle for existence and the operation of natural selection, and the principal objections to the theory, including questions of instinct and hybridisation. In a third work it was intended to test the principle of natural selection by the extent to which it explains the geological succession of organic beings, their distribution in past and present times, and their mutual affinities and homologies. The two latter works were never completed, in consequence of ill-health, and the labour involved in dealing with objections to and new facts in support of the "Origin," and of the other works which at various times it became important to complete. But many portions of these subjects were admirably dealt with by disciples. In some cases Darwin's views led to the rapid growth of a new science, such as that of comparative embryology, and it would not have been possible for him to cope with and interpret the multitude of new and astonishing facts discovered, which changed the face of organic nature as viewed by biologists. By doing each day the work which seemed most necessary, and which he could best do, Darwin managed, in spite of his infirmity of constitution, to complete a larger body of original work, both in experiment and in thought, together with a greater quantity of bibliographical study and collation of observed facts, than any Englishman perhaps has ever done.

The valuable book on "Variation" records and systematises a vast number of facts respecting all our principal domestic animals and cultivated plants. It gives evidence of wide reading, as well as great diligence in writing letters of inquiry to all living authorities who could give accurate information. Very many visits were paid to zoological gardens, breeders' establishments, nursery grounds, &c.; and the preparation of skulls, skins, &c., was a frequent occurrence in the Darwinian laboratory. To take the case of rabbits alone, which occupied but a fraction of the time devoted to pigeons: over twenty works are quoted for historical facts, skeletons of various rabbits were prepared and exhaustively compared, the effects of use and disuse of parts traced, most careful measurements are given, and a list of the modifications which domestic rabbits have undergone, with the probable causes, concludes the chapter. As to pigeons, no pigeon-fancier ought to be without the book, for never assuredly was a sporting topic treated by so great a thinker and so admirably. The numerous experiments in crossing different breeds, and the results obtained, make this one of the most instructive books for all breeders. It would seem desirable that this portion of the book should be issued in a separate form. Again, when we turn to the sections on plants we see how indefatigable Darwin was, for he tells us that he cultivated fifty-four varieties of gooseberries alone, and compared them throughout in flower and fruit.

The chapters on Inheritance, and on Reversion to ancestral characters, or atavism, are profoundly suggestive. What can be more wonderful, the author asks, than that some trifling peculiarity should be transmitted through a long course of development, and ultimately reappear in the offspring when mature or even when old? Nevertheless, the real subject of surprise is not that a character should be inherited, but that any should ever fail to be inherited. Gradually leading up to the important hypothesis with which the work closes, he observes that to adequately explain the numerous characters that reappear after intervals of one or more generations, we must believe that a vast number of characters, capable of evolution, lie hidden in every organic being. "The fertilised germ of one of the higher animals, subjected as it is to so vast a series of changes from the germinal cell to old age—incessantly agitated by what Quatrefages well calls the tourbillon vital—is perhaps the most wonderful object in nature. It is probable that hardly a change of any kind affects either parent, without some mark being left on the germ. But on the doctrine of reversion the germ becomes a far more marvellous object, for, besides the visible changes to which it is subjected, we must believe that it is crowded with invisible characters, proper to both sexes, to both the right and left side of the body, and to a long line of male and female ancestors separated by hundreds or even thousands of generations from the present time; and these characters, like those written on paper with invisible ink, all lie ready to be evolved under certain known or unknown conditions."

Through a further discussion of many deeply interesting facts, about the intercrossing of breeds and species, and about the causes of variability, we pass to the hypothesis of pangenesis, which, briefly stated, supposes that the cells or units of the body are perpetually throwing off minute granules or gemmules, which accumulate in the reproductive system, and may, instead of developing in the next generation, be transmitted in a dormant state through more than one generation and then be developed. Combination in various degrees between these gemmules is supposed to influence their appearance or non-appearance in the offspring at various stages.

This hypothesis certainly gives a picture of a possible mode of accounting for many peculiarities shown by living organisms. Although not generally accepted, it has certainly not been disproved. Mr. Grant Allen's opinion that it is Darwin's "one conspicuous failure," and that it is "crude and essentially unphilosophic," must be discounted by his known devotion to Mr. Herbert Spencer's philosophy. If Darwin had been a specialist in modern physiology, he might, perhaps, have expressed his hypothesis in a more persuasive form; but Weismann's germ plasma theory is the only alternative one hitherto suggested in place of it.



CHAPTER VII.

Although the descent of man from animal ancestors was directly implied in the "Origin of Species," Darwin hesitated at the time of its publication to declare his views fully, believing that he would only thus augment and concentrate the prejudice with which his theory would be met. He had for many years held the views he afterwards expressed; but it was not until he had by his other works raised up a strong body of scientific opinion in favour of his great generalisation, that he fully presented his views on man to the public. The "Descent of Man" was studied as a special case of the application of his general principles, a test all the more severe because several classes of argument were necessarily cut off, such as the nature of the affinities which connect together whole groups of organisms, their geographical distribution, and their geological succession. But adopting the high antiquity of man as demonstrated, he considered in detail the evidence as to man's descent from some pre-existing form, the manner of his development, and the value of the differences between the so-called races of man. No originality is claimed for the theory or for the facts advanced; but it may safely be affirmed that the master's acuteness, his moderation, his candour, and his desire to state facts which tell against him, are as conspicuous in the "Descent of Man" as in any of his works.

The "Descent of Man," which was published in 1871 in two volumes, with numerous illustrations, began, after a short introduction, with a suggestive series of questions, which to the evolutionist suffice to decide the question as to man's origin. As the answers to these questions are obvious, Darwin first concentrated his inquiry upon two points on which disputes must necessarily occur, namely, the traces which man shows, in his bodily structure, of descent from some lower form, and the mental powers of man as compared with those of lower animals. The facts of our bodily structure are inexplicable on any other view than our community of descent with the quadrumana, unless structure is but a snare to delude our reason. It is only our natural prejudice, says Darwin, and that arrogance which made our fathers declare that they were descended from demigods, which leads us to demur to this conclusion.

The comparison of the mental powers of animals with those of man, proving, as Darwin contends, that they therein also show traces of community of descent, was certain to provoke much more debate, for the term "instinct" and the use made of it by naturalists and psychologists as signifying untaught, unlearnt ability, largely tended to obscure the question, and to create prejudices against believing that instincts could be built up by inherited experience, that instincts were really not absolute and fixed, but relative and variable, and that all instincts were not perfect or perfectly useful. The working out of the evolution theory as applied to animal minds, the study of the first beginnings of nerve action, and the analysis of instinct, all due largely to Darwin's prominent disciple, Romanes, together with the immensely fuller knowledge of molecular physics, of protoplasm, and of brain function, acquired in the years since Darwin wrote, have sufficed to place these questions on a much more secure basis. But the collection of facts made by him, and the suggestive remarks he everywhere makes, render his book of permanent value. His sympathy is obvious in such passages as this: "Every one has heard of the dog suffering under vivisection who licked the hand of the operator; this man, unless he had a heart of stone, must have felt remorse to the last hour of his life;" the "terrible" superstitions of the past, such as human sacrifices, trial by ordeal, &c., show us, he says, "what an indefinite debt of gratitude we owe to the improvement of our reason, to science, and our accumulated knowledge." We see the fruit of Darwin's repeated visits to the Zoological Gardens, especially in his study of the habits and mental powers of monkeys. We gain a definition from him of imagination, by which faculty man "unites, independently of the will, former images and ideas, and thus creates brilliant and novel results.... The value of the products of our imagination depends of course on the number, accuracy, and clearness of our impressions; on our judgment and taste in selecting or rejecting the involuntary combinations, and to a certain extent on our power of voluntarily combining them." As to religion, he says, "There is no evidence that man was aboriginally endowed with the ennobling belief in the existence of an omnipotent God." On the contrary, evidence proves that there are and have been numerous races without gods and without words to express the idea. The question, he says, is "wholly distinct from that higher one, whether there exists a Creator and Ruler of the universe; and this has been answered in the affirmative by the highest intellects that have ever lived." The fact of races existing without a belief in a god is shown to be compatible with the origin of religious ideas from attempts to explain external phenomena and man's own existence, by attributing to other objects and agencies a similar spirit to that which his consciousness testifies to in himself.

Man's social qualities, as well as those of animals, Darwin regards as having been developed for the general good of the community, which he defines as "the means by which the greatest possible number of individuals can be reared in full vigour and health, with all their faculties perfect, under the conditions to which they are exposed." This may be regarded as a more satisfactory expression of the idea underlying the phrase, "the greatest happiness of the greatest number." Sympathy for animals he notes as one of the later acquisitions of mankind, and remarks that he found the very idea of humanity a novelty to the Gauchos of the Pampas. "The highest stage in moral culture at which we can arrive is when we recognise that we ought to control our thoughts.... Whatever makes any bad action familiar to the mind, renders its performance so much the easier"—a significant expression for those who would compare the teachings of Darwinism with those of Christianity. Finally, he concludes that the difference in mind between man and the higher animals is one of degree, not of kind. "At what age does the new-born infant possess the power of abstraction, or become self-conscious and reflect on its own existence? We cannot answer; nor can we answer in regard to the ascending organic scale." Yet that man's mental and moral faculties may have been gradually evolved "ought not to be denied, when we daily see their development in every infant; and when we may trace a perfect gradation from the mind of an utter idiot, lower than that of the lowest animal, to the mind of a Newton."

The action of natural selection on the variations known to occur in man, is next shown to be sufficient to account for his rise from a lowly condition. Perhaps it is in discussing the development of the intellectual and moral faculties that Darwin is least successful; more knowledge of psychology than he possessed is demanded for this discussion. He gives up the problem of the first advance of savages towards civilisation as "at present much too difficult to be solved." He, however, vigorously contests the idea that man was at first civilised and afterwards degenerated; and expresses the opinion that the "highest form of religion—the grand idea of God hating sin and loving righteousness—was unknown during primeval times." Finally, after discussing the steps in the genealogy of man, he comes to the conclusion that from the old-world monkeys, at a remote period, proceeded man, "the wonder and glory of the universe." The early progenitors of man he believes to have been covered with hair, both sexes having had beards; their ears were pointed and capable of movement; their bodies were provided with a tail, and the foot was probably prehensile. Our primitive ancestors lived chiefly in trees in some warm forest-clad land, and the males were provided with formidable weapons in the shape of great canine teeth.

"Thus," says Darwin, "we have given to man a pedigree of prodigious length, but not, it may be said, of noble quality. The world, it has been often remarked, appears as if it had long been preparing for the advent of man; and this, in one sense, is strictly true, for he owes his birth to a long line of progenitors. If any single link in this chain had never existed, man would not have been exactly what he now is. Unless we wilfully close our eyes, we may, with our present knowledge, approximately recognize our parentage; nor need we feel ashamed of it. The most humble organism is something much higher than the inorganic dust under our feet; and no one with an unbiassed mind can study any living creature, however humble, without being struck with enthusiasm at its marvellous structure and properties."

In considering the formation and perpetuation of the races of mankind, Darwin was again and again baffled. He could not decide that any of the physical differences between the races are of direct and special service to him, thus giving opportunity to natural selection to work. Hence he was led to study in detail the effects of sexual selection, especially as applicable to man. The greater part of "The Descent of Man" is occupied with tracing out what may be called the history of courtship in man and animals. The great variety of interesting subjects dealt with cannot be detailed here. We must only notice a few points about mankind which are of special importance.

Darwin concludes that man's predominance over woman in size, strength, courage, pugnacity, and even energy was acquired in primeval times, and that these advantages have been subsequently augmented chiefly through the contests between men for women. Even man's intellectual vigour and inventiveness are probably due to natural selection, combined with inherited effects of habit, for the most able men will have succeeded best in defending and providing for their wives and offspring. Beards, beardlessness, voice, beauty are all related to sexual charm, and have been selectively developed. Early man, less licentious, not practising infanticide, was in several respects better calculated to carry out sexual selection than he is now; and thus we find the various races of men fully differentiated at the earliest date of historic records.

Incidentally Darwin gives us his views on the mental differences between man and woman. Woman is more tender and less selfish than man, whose ambition "passes too easily into selfishness," which latter qualities "seem to be his natural and unfortunate birthright." Woman's powers of intuition, of rapid perception, and perhaps of imitation, are more strongly marked than in man. Yet the chief pre-eminence of man he considers to consist in attaining greater success in any given line than woman, by reason of greater energy, patience, &c. "In order that woman should reach the same standard as man, she ought, when nearly adult, to be trained to energy and perseverance, and to have her reason and imagination exercised to the highest point, and then she would probably transmit these qualities chiefly to her adult daughters." Here we have a plan of women's higher education according to the great evolutionist, although he does not assert that it is the essential and desirable one; but given a certain object, here is the best method of securing it. "The whole body of women, however, could not be thus raised, unless during many generations the women who excelled in the above robust virtues were married, and produced offspring in larger numbers than other women."