Pioneers of Evolution from Thales to Huxley

Chapter V: Part IV: Modern Evolution (4)

Text size

So, when this was to be no longer resisted, theologians sought some basis of compromise on such non-fundamental points as the six days of creation. It was suggested that perhaps these did not mean the seventh part of a week, but periods, or eons, or something equally elastic; and that if the Mosaic narrative was regarded as a poetic revelation of the general succession of phenomena, beginning with the development of order out of chaos, and ending with the creation of man, Scripture would be found to have anticipated or revealed what science confirms. It was impossible, so theologians argued, that there could be aught else than harmony between the divine works and the writings which were assumed to be of divine origin. Science could not contradict revelation, and whatever seemed contradictory was due to misapprehension either of the natural fact, or to misreading of the written word. But although the story of the creation might be clothed, as so exalted and moving a theme warranted, in poetic form, that of the fall of Adam and of the drowning of his descendants, eight persons excepted, must be taken in all its appalling literalness. Confirmation of the Deluge story was found in the fossil shells on high mountain tops; while as for the giants of antediluvian times, there were the huge bones in proof. Some of these relics of mastodon and mammoth were actually hung up in churches as evidence that "there were giants in those days"! Geoffroy Saint-Hilaire tells of one Henrion, who published a book in 1718 giving the height of Adam as one hundred and twenty-three feet nine inches, and of Eve as one hundred and eighteen feet nine inches, Noah being of rather less stature. But to parley with science is fatal to theology. Moreover, arguments which involve the cause they support in ridicule may be left to refute themselves. And while theology was hesitating, as in the amusing example supplied by Dr. William Smith's Dictionary of the Bible (published in 1863) wherein the reader, turning up the article "Deluge," is referred to "Flood," and thence to "Noah"; archæology produced the Chaldæan original of the legend whence the story of the flood is derived. With candour as commendable as it is rare, the Reverend Professor Driver, from whom quotation has been made already, admits that "read without prejudice or bias, the narrative of Genesis i. creates an impression at variance with the facts revealed by science"; all efforts at reconciliation being only "different modes of obliterating the characteristic features of Genesis, and of reading into it a view which it does not express."

While the ground in favour of the literal interpretation of Genesis was being contested, an invading force, that had been gathering strength with the years, was advancing in the shape of the science of Biology. The workers therein fall into two classes: the one, represented by Linnaeus and his school, applied themselves to the classifying and naming of plants and animals; the other, represented by Cuvier and his school, examined into structure and function. Anatomy made clear the machinery: physiology the work which it did, and the conditions under which the work was done. Then, through comparison of corresponding organs and their functions in various life-forms, came growing perception of their unity. But only to a few came gleams of that unity as proof of common descent of plant and animal, for, save in scattered hints of inter-relation between species, which occur from the time of Lord Bacon onward, the theory of their immutability was dominant until forty years ago.

Four men form the chief vanguard of the biological movement. "Modern classificatory method and nomenclature have largely grown out of the work of Linnaeus; the modern conception of biology, as a science, and of its relation to climatology, geography, and geology, are as largely rooted in the labours of Buffon; comparative anatomy and palæontology owe a vast debt to Cuvier's results; while invertebrate zoology and the revival of the idea of Evolution are intimately dependent on the results of the work of Lamarck. In other words, the main results of biology up to the early years of this century are to be found in, or spring out of, the works of these men."

Linnaeus, son of a Lutheran pastor, born at Roeshult, in Sweden, in 1707, had barely passed his twenty-fifth year before laying the ground-plan of the system of classification which bears his name, a system which advance in knowledge has since modified. Based on external resemblances, its formulation was possible only to a mind intent on minute and accurate detail, and less observant of general principles. In brief, the work of Linnaeus was constructive, not interpretative. Hence, perhaps, conjoined to the theological ideas then current, the reason why the larger question of the fixity of species entered not into his purview. To him each plant and animal retained the impress of the Creative hand that had shaped it "in the beginning," and, throughout his working life, he departed but slightly from the plan with which he started, namely, "reckoning as many species as issued in pairs" from the Almighty fiat.

Not so Buffon, born on his father's estate in Burgundy in the same year as Linnaeus, whom he survived ten years, dying in 1788. His opinions, clashing as they did with orthodox creeds, were given in a tentative, questioning fashion, so that where ecclesiastical censure fell, retreat was easier. As has been seen in his submission to the Sorbonne, he was not of the stuff of which martyrs are made. Perhaps he felt that the ultimate victory of his opinions was sufficiently assured to make self-sacrifice needless. But, under cover of pretence at inquiry, his convictions are clear enough. He was no believer in the permanent stability of species, and noted, as warrant of this, the otherwise unexplained presence of aborted or rudimentary structures. For example, he says, "the pig does not appear to have been formed upon an original, special, and perfect plan, since it is a compound of other animals; it has evidently useless parts, or rather, parts of which it cannot make any use, toes, all the bones of which are perfectly formed, and which, nevertheless, are of no service to it. Nature is far from subjecting herself to final causes in the formation of her creatures." Then, further, as showing his convictions on the non-fixity of species, he says, how many of them, "being perfected or degenerated by the great changes in land and sea, by the favours or disfavours of Nature, by food, by the prolonged influences of climate, contrary or favourable, are no longer what they formerly were." But he writes with an eye on the Sorbonne when, hinting at a possible common ancestor of horse and ass, and of ape and man, he slyly adds that since the Bible teaches the contrary, the thing cannot be. Thus he attacked covertly; by adit, not by direct assault; and to those who read between the lines there was given a key wherewith to unlock the door to the solution of many biological problems. Buffon, consequently, was the most stimulating and suggestive naturalist of the eighteenth century. There comes between him and Lamarck, both in order of time and sequence of ideas, Erasmus Darwin, the distinguished grandfather of Charles Darwin.

Born at Eton, near Newark, in 1731, he walked the hospitals at London and Edinburgh, and settled, for some years, at Lichfield, ultimately removing to Derby. Since Lucretius, no scientific writer had put his cosmogonic speculations into verse until Dr. Darwin made the heroic metre, in which stereotyped form the poetry of his time was cast, the vehicle of rhetorical descriptions of the amours of flowers and the evolution of the thumb. The Loves of the Plants, ridiculed in the Loves of the Triangles in the Anti-Jacobin, is not to be named in the same breath, for stateliness of diction, and majesty of movement, as the De rerum Natura. But both the prose work Zoonomia and the poem The Temple of Nature (published after the author's death in 1802) have claim to notice as the matured expression of conclusions at which the clear-sighted, thoughtful, and withal, eccentric doctor had arrived in the closing years of his life. Krause's Life and Study of the Works of Erasmus Darwin supplies an excellent outline of the contents of books which are now rarely taken down from the shelves, and makes clear that their author had the root of the matter in him. His observations and reading, for the influence of Buffon and others is apparent in his writings, led him to reject the current belief in the separate creation of species. He saw that this theory wholly failed to account for the existence of abnormal forms, of adaptations of the structure of organs to their work, of gradations between living things, and other features inconsistent with the doctrine of "let lions be, and there were lions." His shrewd comment on the preformation notion of development has been quoted (p. 20). The substance of his argument in support of a "physical basis of life" is as follows: "When we revolve in our minds the metamorphosis of animals, as from the tadpole to the frog; secondly, the changes produced by artificial cultivation, as in the breeds of horses, dogs, and sheep; thirdly, the changes produced by conditions of climate and of season, as in the sheep of warm climates being covered with hair instead of wool, and the hares and partridges of northern climates becoming white in winter; when, further, we observe the changes of structure produced by habit, as seen especially by men of different occupations; or the changes produced by artificial mutilation and prenatal influences, as in the crossing of species and production of monsters; fourth, when we observe the essential unity of plan in all warm-blooded animals--we are led to conclude that they have been alike produced from a similar living filament." The concluding words of this extract make remarkable approach to the modern theory of the origin of life in the complex jelly-like protoplasm, or, as some call it, nuclein or nucleoplasm. And, on this, Erasmus Darwin further remarks: "As the earth and ocean were probably peopled with vegetable productions long before the existence of animals, and many families of these animals long before other animals of them, shall we conjecture that one and the same kind of living filament is and has been the cause of all organic life?" Nor does he make any exception to this law of organic development. He quotes Buffon and Helvetius to the effect--"that many features in the anatomy of man point to a former quadrupedal position, and indicate that he is not yet fully adapted to the erect position; that, further, man may have arisen from a single family of monkeys, in which, accidentally, the opposing muscle brought the thumb against the tips of the fingers, and that this muscle gradually increased in size by use in successive generations." While we who live in these days of fuller knowledge of agents of variation may detect the _minus_ in all foregoing speculations, our interest is increased in the thought of their near approach to the cardinal discovery. And a rapid run through the later writings of Dr. Darwin shows that there is scarcely a side of the great theory of Evolution which has escaped his notice or suggestive comment. Grant Allen, in his excellent little monograph on Charles Darwin, says that the theory of "natural selection was the only cardinal one in the evolutionary system on which Erasmus Darwin did not actually forestall his more famous and greater namesake. For its full perception, the discovery of Malthus had to be collated with the speculations of Buffon."

In the Historical Sketch on the Progress of Opinion on the Origin of Species, which Darwin prefixed to his book, he refers to Lamarck as "the first man whose conclusions on the subject excited much attention;" rendering "the eminent service of arousing attention to the probability of all change in the organic, as well as in the inorganic world, being the result of law, and not of miraculous interposition." Lamarck was born at Bezantin, in Picardy, in 1744. Intended for the Church, he chose the army, but an injury resulting from a practical joke cut short his career as a soldier. He then became a banker's clerk, in which occupation he secured leisure for his favourite pursuit of natural history. Through Buffon's influence he procured a civil appointment, and ultimately became a colleague of Cuvier and Geoffroy St. Hilaire in the Museum of Natural History at Paris. Of Cuvier it will here suffice to say that he remained to the end of his life a believer in special creation, or, what amounts to the same thing, a series of special creations which, he held, followed the catastrophic annihilations of prior plants and animals. Although orthodox by conviction, his researches told against his tenets, because his important work in the reconstruction of skeletons of long extinct animals laid the foundation of palæontology.

To Lamarck, says Haeckel, "will always belong the immortal glory of having for the first time worked out the Theory of Descent as an independent scientific theory of the first order, and as the philosophical foundation of the whole science of Biology." He taught that in the beginnings of life only the very simplest and lowest animals and plants came into existence; those of more complex structure developing from these; man himself being descended from ape-like mammals. For the Aristotelian mechanical figure of life as a ladder, with its detached steps, he substituted the more appropriate figure of a tree, as an inter-related organism. He argued that the course of the earth's development, and also of all life upon it, was continuous, and not interrupted by violent revolutions. In this he followed Buffon and Hutton. Buffon, in his Theory of the Earth, argues that "in order to understand what had taken place in the past, or what will happen in the future, we have but to observe what is going on in the present." This is the keynote of modern geology. "Life," adds Lamarck, "is a purely physical phenomenon. All its phenomena depend on mechanical, physical, and chemical causes which are inherent in the nature of matter itself." He believed in a form of spontaneous generation. Rejecting Buffon's theory of the direct action of the surroundings as agents of change in living things, he sums up the causes of organic evolution in the following propositions:

1. Life tends by its inherent forces to increase the volume of each living body and of all its parts up to a limit determined by its own needs.

2. New wants in animals give rise to new movements which produce organs.

3. The development of these organs is in proportion to their employment.

4. New developments are transmitted to offspring.

The second and third propositions were illustrated by examples which have, with good reason, provoked ridicule. Lamarck accounts for the long neck of the giraffe by that organ being continually stretched out to reach the leaves at the tree-tops; for the long tongue of the ant-eater or the woodpecker by these creatures protruding it to get at food in channel or crevice; for the webbed feet of aquatic animals by the outstretching of the membranes between the toes in swimming; and for the erect position of man by the constant efforts of his ape-like ancestors to keep upright. The legless condition of the serpent which, in the legend of the Garden of Eden, is accounted for on moral grounds, is thus explained by Lamarck: "Snakes sprang from reptiles with four extremities, but having taken up the habit of moving along the earth and concealing themselves among bushes, their bodies, owing to repeated efforts to elongate themselves and to pass through narrow spaces, have acquired a considerable length out of all proportion to their width. Since long feet would have been very useless, and short feet would have been incapable of moving their bodies, there resulted a cessation of use of these parts, which has finally caused them to totally disappear, although they were originally part of the plan of organization in these animals." The discovery of an efficient cause of modifications, which Lamarck refers to the efforts of the creatures themselves, has placed his speculations in the museum of biological curiosities; but sharp controversy rages to-day over the question raised in Lamarck's fourth proposition, namely, the transmission of characters acquired by the parent during its lifetime to the offspring. This burning question between Weismann and his opponents, involving the serious problem of heredity, will remain unsettled till a long series of observations supply material for judgment.

Lamarck, poor, neglected, and blind in his old age, died in 1829. Both Cuvier, who ridiculed him, and Goethe, who never heard of him, passed away three years later. The year following his death, when Darwin was an undergraduate at Cambridge, Lyell published his Principles of Geology, a work destined to assist in paving the way for the removal of one difficulty attending the solution of the theory of the origin of species, namely, the vast period of time for the life-history of the globe which that theory demands. As Lyell, however, was then a believer--although, like a few others of his time, of wavering type--in the fixity of species, he had other aims in view than those to which his book contributed. But he wrote with an open mind, not being, as Herbert Spencer says of Hugh Miller, "a theologian studying geology." Following the theories of uniformity of action laid down by Hutton, by Buffon, and by that industrious surveyor, William Smith, who travelled the length and breadth of England, mapping out the sequence of the rocks, and tabulating the fossils special to each stratum, Lyell demonstrated in detail that the formation and features of the earth's crust are explained by the operation of causes still active. He was one among others, each working independently at different branches of research; each, unwittingly, collecting evidence which would help to demolish old ideas, and support new theories.

A year after the Principles of Geology appeared, there crept unnoticed into the world a treatise, by one Patrick Matthew, on Naval Timber and Arboriculture, under which unexciting title Darwin's theory was anticipated. Of this, however, as of a still earlier anticipation, more presently. About this period Von Baer, in examining the embryos of animals, showed that creatures so unlike one another in their adult state as fishes, lizards, lions, and men, resemble one another so closely in the earlier stages of their development that no differences can be detected between them. But Von Baer was himself anticipated by Meckel, who wrote as follows in 1811: "There is no good physiologist who has not been struck, incidentally, by the observation that the original form of all organisms is one and the same, and that out of this one form, all, the lowest as well as the highest, are developed in such a manner that the latter pass through the permanent forms of the former as transitory stages" (Osborn's From the Greeks to Darwin, p. 212). In botany Conrad Sprengel, who belongs to the eighteenth century, had shown the work effected by insects in the fertilization of plants. Following his researches, Robert Brown made clear the mode of the development of plants, and Sir William Hooker traced their habits and geographical distribution. Von Mohl discovered that material basis of both plant and animal which he named "protoplasm." In 1844, nine years before Von Mohl told the story of the building-up of life from a seemingly structureless jelly, a book appeared which critics of the time charged with "poisoning the fountains of science, and sapping the foundations of religion." This was the once famous Vestiges of Creation, acknowledged after his death as the work of Robert Chambers, in which the origin and movements of the solar system were explained as determined by uniform laws, themselves the expression of Divine power. Organisms, "from the simplest and oldest, up to the highest and most recent," were the result of an "inherent impulse imparted by the Almighty both to advance them from the several grades and modify their structure as circumstances required." Although now referred to only as "marking time" in the history of the theory of Evolution, the book created a sensation which died away only some years after its publication. Darwin remarks upon it in his Historical Sketch that although displaying "in the earlier editions little accurate knowledge and a great want of scientific knowledge, it did excellent service in this country in calling attention to the subject, in removing prejudice, and in thus preparing the ground for the reception of analogous views."

Three years after the Vestiges, there was, although none then knew it, or knowing the fact, would have admitted it, more "sapping of the foundations" of orthodox belief, when M. Boucher de Perthes exhibited some rudely-shaped flint implements which had been found at intervals in hitherto undisturbed deposits of sand and gravel--old river beds--in the Somme valley, near Abbeville, in Picardy. For these rough stone tools and weapons, being of human workmanship, evidenced the existence of savage races of men in Europe in a dim and dateless past, and went far to refute the theories of his paradisiacal state on that memorable "23 October, 4004 B. C.," when, according to Dr. Lightfoot's reckoning (see p. 103), Adam was created. While the pickaxe, in disturbing flint knives and spearheads, that had lain for countless ages, was disturbing much besides, English and German philosophers were formulating the imposing theory which, under the name of the Conservation of Energy, makes clear the indestructibility of both matter and motion. Then, to complete the work of preparation effected by the discoveries now briefly outlined, there appeared, in a now defunct newspaper, the Leader, in its issue of 20th of March, 1852, an article by Herbert Spencer on the Development Hypothesis, in which the following striking passage occurs: "Those who cavalierly reject the Theory of Evolution, as not adequately supported by facts, seem quite to forget that their own theory is supported by no facts at all. Like the majority of men who are born to a given belief, they demand the most rigorous proof of any adverse belief, but assume that their own needs none. Here we find, scattered over the globe, vegetable and animal organisms numbering, of the one kind (according to Humboldt) some 320,000 species, and of the other, some 2,000,000 species (see Carpenter); and if to these we add the numbers of animal and vegetable species that have become extinct, we may safely estimate the number of species that have existed, and are existing, on the earth, at not less than _ten millions_. Well, which is the most rational theory about these ten millions of species? Is it most likely that there have been ten millions of special creations? or is it most likely that by continual modifications, due to change of circumstances, ten millions of varieties have been produced, as varieties are being produced still?... Even could the supporters of the Development Hypothesis merely show that the origination of species by the process of modification is conceivable, they would be in a better position than their opponents. But they can do much more than this. They can show that the process of modification has effected, and is effecting, decided changes in all organisms subject to modifying influences.... They can show that in successive generations these changes continue, until ultimately the new conditions become the natural ones. They can show that in cultivated plants, domesticated animals, and in the several races of men, such alterations have taken place. They can show that the degrees of difference so produced are often, as in dogs, greater than those on which distinctions of species are in other cases founded. They can show, too, that the changes daily taking place in ourselves--the facility that attends long practice, and the loss of aptitude that begins when practice ceases--the strengthening of passions habitually gratified, and the weakening of those habitually curbed--the development of every faculty, bodily, moral, or intellectual, according to the use made of it--are all explicable on this same principle. And thus they can show that throughout all organic nature there is at work a modifying influence of the kind they assign as the cause of these specific differences; an influence which, though slow in its action, does, in time, if the circumstances demand it, produce marked changes--an influence which, to all appearance, would produce in the millions of years, and under the great varieties of condition which geological records imply, any amount of change."

This quotation shows, as perhaps no other reference might show, how, by the middle of the present century, science was trembling on the verge of discovery of that "modifying influence" of which Mr. Spencer speaks. That discovery made clear how all that had preceded it not only contributed thereto, but gained a significance and value which, apart from it, could not have been secured. When the relation of the several parts to the whole became manifest, each fell into its place like the pieces of a child's puzzle map.

LEADING MEN OF SCIENCE.

A. D. 800 TO A. D. 1800.

_PART IV._

MODERN EVOLUTION.

1. _Darwin and Wallace._

We have to deal with Man as a product of Evolution; with Society as
a product of Evolution; and with Moral Phenomena as products of
Evolution.--HERBERT SPENCER, Principles of Ethics, § 193.

CHARLES ROBERT DARWIN (the second name was rarely used by him) was born at Shrewsbury on the 12th of February, 1809. He came of a long line of Lincolnshire yeomen, whose forbears spelt the name variously, as Darwen, Derwent, and Darwynne, perhaps deriving it from the river of kindred name. His father was a kindly, prosperous doctor, of sufficient scientific reputation to secure his election into the Royal Society, although that coveted honour was then more easily obtained than now. Of the more famous grandfather, Erasmus Darwin, the reminder suffices that both his prose and poetry were vehicles of suggestive speculations on the development of life-forms. Dealing with bald facts and dates for clearance of what follows, it may be added that Charles Darwin was educated at the Grammar School of his native town; that he passed thence to Edinburgh and Cambridge Universities; was occupied as volunteer naturalist on board the Beagle from December, 1831, till October, 1836; that he published his epoch-making Origin of Species in November, 1859; and that he was buried by the side of Sir Isaac Newton in Westminster Abbey on the 26th of April, 1882.

As with not a few other men of "light and leading," neither school nor university did much for him, nor did his boyhood give indication of future greatness. In his answers to the series of questions addressed to various scientific men in 1873 by his distinguished cousin, Francis Galton, he says: "I consider that all I have learnt of any value has been self-taught," and he adds that his education fostered no methods of observation or reasoning. Of the Shrewsbury Grammar School, where, after the death of his mother (daughter of Josiah Wedgwood, the celebrated potter), in his ninth year, he was placed as a boarder till his sixteenth year, he tells us, in the modest and candid Autobiography printed in the Life and Letters, "nothing could have been worse for the development of my mind." All that he was taught were the classics, and a little ancient geography and history; no mathematics, and no modern languages. Happily, he had inherited a taste for natural history and for collecting, his spoils including not only shells and plants, but also coins and seals. When the fact that he helped his brother in chemical experiments became known to Dr. Butler, the head-master, that desiccated pedagogue publicly rebuked him "for wasting time on such useless subjects." Then his father, angry at finding that he was doing no good at school, reproved him for caring for nothing but shooting, dogs, and rat-catching, and declared that he would be a disgrace to the family! He sent him to Edinburgh University with his brother to study medicine, but Darwin found the dulness of the lectures intolerable, and the sight of blood sickened him, as it did his father. Although the effect of the "incredibly" dry lectures on geology made him--the future Secretary of the Geological Society!--vow never to read a book on the science, or in any way study it, his interest in biological subjects grew, and its first fruits were shown in a paper read before the Plinian Society at Edinburgh in 1826, in which he reported his discovery that the so-called ova of _Flustra_, or the sea-mat, were larvæ.

But his father had to accept the fact that Darwin disliked the idea of being a doctor, and fearing that he would degenerate into an idle sporting man, proposed that he should become a clergyman! Darwin says upon this:--

I asked for some time to consider, as from what little I had heard
or thought on the subject I had scruples about declaring my belief
in all the dogmas of the Church of England, though otherwise I liked
the thought of being a country clergyman. Accordingly I read with
care Pearson on the Creed, and a few other books on divinity; and,
as I did not then in the least doubt the strict and literal truth of
every word in the Bible, I soon persuaded myself that our creed must
be fully accepted. Considering how fiercely I have been attacked by
the orthodox, it seems ludicrous that I once intended to be a
clergyman. Nor was this intention and my father's wish ever
formally given up, but died a natural death when, on leaving
Cambridge, I joined the Beagle as naturalist. If the phrenologists
are to be trusted, I was well fitted in one respect to be a
clergyman. A few years ago the secretaries of a German psychological
society asked me earnestly by letter for a photograph of myself; and
some time afterwards I received the proceedings of one of the
meetings, in which it seemed that the shape of my head had been the
subject of a public discussion, and one of the speakers declared
that I had the bump of reverence developed enough for ten priests.

The result was that early in 1828 Darwin went to Cambridge, the three years spent at which were "time wasted, as far as the academical studies were concerned." His passion for shooting and hunting led him into a sporting, card-playing, drinking company, but science was his redemption. No pursuit gave him so much pleasure as collecting beetles, of his zeal in which the following is an example: "One day, on tearing off some old bark, I saw two rare beetles, and seized one in each hand; then I saw a third and new kind, which I could not bear to lose, so I popped the one which I held in my right hand into my mouth. Alas! it ejected some intensely acrid fluid, which burnt my tongue so that I was forced to spit the beetle out, which was lost, as was the third one."

Happily for his future career, and therefore for the interests of science, Darwin became intimate with men like Whewell, Henslow, and Sedgwick, while the reading of Humboldt's Personal Narrative, and of Sir John Herschel's Introduction to Natural Philosophy, stirred up in him "a burning zeal to add even the most humble contribution to the noble structure of Natural Science." The vow to eschew geology was quickly broken when he came under the spell of Sedgwick's influence, but it was the friendship of Henslow that determined his after career, and prevented him from becoming the "Rev. Charles Darwin." For on his return from a geological tour in Wales with Sedgwick he found a letter from Henslow awaiting him, the purport of which is in the following extract:--

"I have been asked by Peacock (Lowndean Professor of Astronomy at Cambridge) to recommend him a naturalist as companion to Captain Fitz-Roy, employed by Government to survey the southern extremity of America. I have stated that I consider you to be the best-qualified person I know of who is likely to undertake such a situation."

In connection with this the following memorandum from Darwin's pocket-book of 1831 is of interest:--"Returned to Shrewsbury at end of August. Refused offer of voyage."

This refusal was given at the instance of his father, who objected to the scheme as "wild and unsettling, and as disreputable to his character as a clergyman"; but he soon yielded on the advice of his brother-in-law, Josiah Wedgwood, and on Darwin's plea that he "should be deuced clever to spend more than his allowance whilst on board the Beagle." On this his father answered with a smile, "But they tell me you are very clever." It is amusing to find that Darwin narrowly escaped being rejected by Fitz-Roy, who, as a disciple of Lavater, doubted whether a man with such a nose as Darwin's "could possess sufficient energy and determination for the voyage."

The details of that voyage, the first of the two memorable events in Darwin's otherwise unadventurous life, are set down in delightful narrative in his Naturalist's Voyage Round the World, and it will suffice to quote a passage from the autobiography bearing on the significance of the materials collected during his five years' absence.

During the voyage of the Beagle I had been deeply impressed by
discovering in the Pampean formation great fossil animals covered
with armour like that on the existing armadillos; secondly, by the
manner in which closely allied animals replace one another in
proceeding southwards over the continent; and thirdly, by the South
American character of most of the productions of the Galapagos
Archipelago, and more especially by the manner in which they differ
slightly on each island of the group, none of the islands appearing
to be very ancient in a geological sense. It was evident that such
facts as these, as well as many others, could only be explained on
the supposition that species gradually became modified; and the
subject haunted me. But it was equally evident that "none of the
evolutionary theories then current in the scientific world" could
account for the innumerable cases in which organisms of every kind
are beautifully adapted to their habits of life.... I had always
been much struck by such adaptations, and until these could be
explained, it seemed to me almost useless to endeavour to prove by
indirect evidence that species have been modified.... In October,
1838, that is, fifteen months after I had begun my systematic
inquiry, I happened to read for amusement Malthus on Population, and
being well prepared to appreciate the struggle for existence which
everywhere goes on, from long-continued observations of the habits
of plants and animals, it at once struck me that under these
circumstances favourable variations would tend to be preserved, and
unfavourable ones destroyed. The result of this would be the
formation of new species.

Shortly after his return he settled in London, prepared his journal and manuscripts of observations for publication, and opened, he says, under date of July, 1837, "my first note-book for facts in relation to the origin of species, about which I had long reflected, and never ceased working for the next twenty years." He acted for two years as one of the honorary secretaries of the Geological Society, which brought him into close relations with Lyell, and, as his health then allowed him to go into society, he saw a good deal of prominent literary and scientific contemporaries.

In the autumn of 1842, two years and eight months after his marriage with his first cousin, Emma Wedgwood, who died in October last (1896), Darwin removed from London, the air and social demands of which were alike unsuited to his health, and finally fixed upon a house in the secluded village of Down, near Beckenham, where he spent the rest of his days. Henceforth the life of Darwin is merged in the books in which, from time to time, he gave the result of his long years of patient observation and inquiry, from the epoch-making Origin to the monograph on earthworms. With bad health, apparently due to gouty tendencies aggravated by chronic sea-sickness during his voyage; with nights that never gave unbroken sleep; and days that were never passed without prostrating pain; he might well have felt justified in doing nothing whatever. But he was saved from the accursed monotony of a wealthy invalid's life by his insatiate delight in searching for that solution of the problem of the mutability of species which time would not fail to bring. In this, he tells us, he forgot his "daily discomfort," and thus was delivered from morbid introspection.

Darwin worked at his rough notes on the variation of animals and plants under domestication, adding facts collected by "printed enquiries, by conversations with skilful breeders and gardeners, and by extensive reading," gleams of light coming till he says that he is "almost convinced that species are not (it is like confessing a murder) immutable." But he was still groping in the dark as to the application of selection to wild plants and animals, until, as remarked above, the chance reading of Malthus suggested a working theory. A brief sketch of this theory, written out in pencil in 1842, was elaborated in 1844 into an essay of two hundred and thirty pages. The importance attached to this was shown in a letter which Darwin then addressed to his wife, charging her, in the event of his death, to apply £400 to the expense of publication. He also named certain competent men from whom an editor might be chosen, preference being given to Sir Charles (then Mr. Lyell, at whose advice Darwin began to write out his views on a scale three or four times as extensive as that in which they appeared in the Origin of Species.) Their publication in an abstract form was hastened by the receipt, in June, 1858, of a paper, containing "exactly the same theory," from Mr. Alfred Russel Wallace at Ternate in the Moluccas. This reference to that distinguished explorer, will, before the story of the coincident discovery is further told, fitly introduce a sketch of his career.

ALFRED RUSSEL WALLACE was born at Usk, in Monmouthshire, on the 8th of January, 1823. He was educated at Hereford Grammar School, and in his fourteenth year began the study of land-surveying and architecture under an elder brother. Quick-witted and observing, he studied a great deal more on his own account in his journeyings over England and Wales, the results of which abide in the wide range of subjects--scientific, political, and social--engaging his active pen from early manhood to the present day.

About 1844 he exchanged the theodolite for the ferule, and became English master in the Collegiate School at Leicester, in which town he found a congenial friend in the person of his future fellow-traveller, Henry Walter Bates. Bates was then employed in his father's hosiery warehouse, from which he escaped, as often as the long working hours then prevailing allowed, into the fields with his collecting-box. Both schoolmaster and shopman were ardent naturalists, Mr. Wallace, as he tells us, being at that time "chiefly interested in botany," but he afterward took up his friend's favourite pursuit of entomology. The writer, when preparing his memoir of Bates (which prefaces a reprint of the first edition of the delightful Naturalist on the Amazons), learned from Mr. Wallace that in early life he did not keep letters from Bates and other correspondents. But, fortunately, among Bates's papers, there was a bundle of interesting letters from Wallace written between June, 1845, and October, 1847, from Neath, in South Wales, to which town he had removed. In one of these, dated the 9th of November, 1845, Wallace asks Bates if he had read the Vestiges of the Natural History of Creation, and a subsequent letter indicates that Bates had not formed a favourable opinion of the book. A later letter is interesting as conveying an estimate of Darwin. "I first," Wallace says, "read Darwin's Journal three or four years back, and have lately re-read it. As the journal of a scientific traveller, it is second only to Humboldt's Personal Narrative; as a work of general interest, perhaps supporter to it. He is an ardent admirer and most able supporter of Mr. Lyell's views. His style of writing I very much admire, so free from all labour, affectation, or egotism, yet so full of interest and original thought."

But, of still greater moment, is a letter in which Wallace tells Bates that he begins "to feel dissatisfied with a mere local collection. I should like to take some one family to study thoroughly, principally with a view to the theory of the origin of species." The two friends had often discussed schemes for going abroad to explore some virgin region, nor could their scanty means prevent the fulfilment of a scheme which has enriched both science and the literature of travel. The choice of country to explore was settled by Wallace's perusal of a little book entitled A Voyage up the River Amazons, including a Residence in Pará, by W. H. Edwards, an American tourist, published in Murray's Family Library, in 1847. In the autumn of that year Wallace proposed a joint expedition to the river Amazons for the purpose of exploring the Natural History of its banks; the plan being to make a collection of objects, dispose of the duplicates in London to pay expenses, and gather facts, as Mr. Wallace expressed it in one of his letters, "towards solving the problem of the origin of species."

The choice was a happy one, for, except by the German zoologist Von Spix, and the botanist Von Martius in 1817-20, and subsequently by Count de Castelnau, no exploration of a region so rich and interesting to the biologist had been attempted. Early in 1848 Bates and Wallace met in London to study South American animals and plants in the principal collections, and afterward went to Chatsworth to gain information about orchids, which they proposed to collect in the moist tropical forests and send home.

On 26th of April, 1848, they embarked at Liverpool in a barque of only 192 tons burden, one of the few ships then trading to Pará, to which seaport of the Amazons region a swift passage, "straight as an arrow," brought them on 28th of May.

The travellers soon settled in a _rocinha_, or country-house, a mile and half from Pará, and close to the forest, which came down to their doors. Like other towns along the Amazons, Pará stands on ground cleared from the forest that stretches, a well-nigh pathless jungle of luxuriant primeval vegetation, two thousand miles inland. In that paradise of the naturalist, the collectors gathered consignments which met with ready sale in London, and thus spent a couple of years in pursuits moderately remunerative and wholly pleasurable, till, on reaching Barra, at the mouth of the Rio Negro, one thousand miles from Pará, in March, 1850, Bates and Wallace, who was accompanied by his younger brother, parted company, "finding it more convenient to explore separate districts and collect independently." Wallace took the northern parts and tributaries of the Amazons, and Bates kept to the main stream, which, from the direction it seems to take at the fork of the Rio Negro, is called the Upper Amazons or the Solimoens. Different in character and climatic conditions from the Lower Amazons, it flows through a "vast plain about a thousand miles in length, and five hundred or six hundred miles in breadth covered with one uniform, lofty, impervious, and humid forest." Bates stayed in the country till June, 1859, but Wallace left in 1852, and in the following year published an account of his journey under the title of Travels on the Amazon and Rio Negro. That book was written under the serious disadvantage of the destruction of the greater part of the notes and specimens by the burning of the ship in which Mr. Wallace took passage on his homeward voyage. That it remains one of the select company of works of travel for which demand is continuous is evidenced in a reprint which appeared in 1891. If it affords few hints of the author's bent of mind toward the question of the origin of species, it shows what interest was being aroused within him over the allied subject of the geographical distribution of plants and animals which Mr. Wallace was to make so markedly his own.

In 1854 he sailed for the Malay Archipelago, where nearly eight years were spent in exploring the region from Sumatra to New Guinea. The large and varied outcome of that labour was embodied in numerous papers communicated to learned societies and scientific journals, and in a series of delightful books from The Malay Archipelago, first published in 1869, to Island Life, published in 1880. Among the minor results of his extensive travels--for all else that Wallace did pales before the great discovery which links his name with Darwin's--was the establishment of a line, known as "Wallace's," which divides the Malay Archipelago into two main groups, "Indo-Malaysia and Austro-Malaysia, marked by distinct species and groups of animals." That line runs through a deep channel separating the islands of Bali and Lombok; the plants and animals on which, although but fifteen miles of water separate them, differ from each other even more than do the islands of Great Britain and Japan. "A similar line, but somewhat farther east, divides on the whole the Malay from the Papuan races of man."

Among the more fugitive contributions which mark Mr. Wallace's approach to a solution of the problem in quest of which he and Bates went to the Amazons is a paper On the Law which has Regulated the Introduction of New Species, published in the Annals and Magazine of Natural History, 1855. In this he shows that some form of evolution of one species from another is needed to explain the geological and geographical facts of which examples are given.

In the interesting preface to the reprint of the famous paper On the Tendencies of Varieties to depart Indefinitely from the Original Type, Mr. Wallace recites the several researches which he made in quest of that "form" till, when lying ill with fever at Ternate, in February, 1858, something led him to think of the "positive checks" described by Malthus in his Essay on Population, a book which he had read some years before. Oddly enough, therefore, the honours lie with the maligned Haileybury Reverend Professor of Political Economy in furnishing both Darwin and Wallace with the clue. The "positive checks"--war, disease, famine--Wallace felt must act even more effectively on the lower animals than on man, because of their more rapid rate of multiplication. And he tells us, in the prefatory note to a reprint of his paper, "there suddenly flashed on me the _idea_ of the survival of the fittest, and in the two hours that elapsed before my ague fit was over I had thought out the whole of the theory, and in the two succeeding evenings wrote it out in full and sent it by the next post to Mr. Darwin," asking him, if he thought well of the essay, to send it to Lyell. This Darwin did with the following remarks: "Your words have come true with a vengeance--that I should be forestalled.... I never saw a more striking coincidence; if Wallace had my MS. sketch written out in 1842, he could not have made a better short abstract! Even his terms now stand as heads of my chapters. Please return me the MS., which he does not say he wishes me to publish; but I shall, of course, at once write and offer to send to any journal. So all my originality, whatever it may amount to, will be smashed, though my book, if it will ever have any value, will not be deteriorated, as all the labour consists in the application of the theory." Darwin came out well in this business. For to have hit upon a theory which interprets so large a question as the origin and causes of modification of life-forms; to keep on turning it over and over again in the mind for twenty long years; to spend the working hours of every day in collection and verification of facts for and against it; and then to have another man launching a "bolt from the blue" in the shape of a paper with exactly the same theory, might well disturb even a philosopher of Darwin's serenity.

Previous Next

Comments

Pioneers of Evolution from Thales to HuxleyChapter V: Part IV: Modern Evolution (4)

0%36 min left in chapter