384
DARWIN
about half of it when, on June 18, 1858, he received a the new theory, explaining by its aid the colours of desert manuscript essay from A. R. Wallace, who was then, at birds, &c. (Ibis, October 1859). Acting under the advice of Lyell and Hooker, Darwin Ternate in the Moluccas. Wallace wanted Darwin’s then began to prepare what was to become the great work opinion on the essay, which he asked should be forwarded of his life. It appeared November 24, 1859, with the full to Lyell. Darwin was much startled to find in the essay title, On Origin of Species by Means of Natural a complete abstract of his own theory of natural selection. Selection, the or the Preservation of Favoured Paces in the He forwarded it the same day, writing to Lyell, your words have come true with a vengeance—that I should be Struggle for Life. The whole edition of 1250 copies was forestalled.” He placed himself in the hands of Lyell and exhausted on the day of issue. The first four chapters Hooker, who decided to send Wallace’s essay to the explain the operation of artificial selection by man and of Linnean Society, together with an abstract of Darwin’s natural selection in consequence of the struggle for existwork, which they asked him to prepare, the joint essay ence. The fifth chapter deals with the laws of variation being accompanied by a preface in the form of an explana- and causes of modification other than natural selection. tory letter written by them to the secretary. The title The five succeeding chapters consider difficulties in the way of the joint communication was “ On the Tendency of of a belief in evolution generally as well as in natural Species to form Varieties; and on the Perpetuation of selection. The three remaining chapters (omitting the reVarieties and Species by Natural Means of Selection.” It capitulation which occupies the last) deal with the evidence was read on July 1, 1858, and appears in the Linn. Soc. for evolution. The theory which suggested a cause of Journal (Zoology) for that year. In this statement of evolution is thus given the foremost place, and the evidence the Theory of Natural Selection, Darwin’s part consisted for the existence of evolution considered last of all. This of two sections, the first being extracts from his 1844 method of presentation was no doubt adopted because it essay, including a brief account of sexual selection; the was just the want of a reasonable motive-cause which more second consisting of an abstract of his letter to Asa than anything else prevented the acceptance of evolution. Gray dated September 5, 1857. This latter, probably his But the other side of the book must not be eclipsed by first attempt to expound natural selection, cannot be sur- the brilliant theory of Darwin and Wallace. The evidence passed as a clear statement of the theory. Darwin ex- for evolution itself had never before been thought out and plained at the outset, what he insisted on elsewhere, that marshalled in a manner which bears any comparison with the facts of adaptation or contrivance in nature are the that of Darwin in the Origin, and the work would have real difficulty to be explained by a theory of evolution, the been in the highest degree epoch-making had it consisted stumbling-block of every previous suggestion. Until he of the later chapters alone. In the fifth chapter Darwin could explain “the mistletoe, with its pollen carried by incorporated a certain proportion of the doctrines of insects, and seed by birds—the woodpecker, with its feet Buffon,—modifications due to the direct influence of enand tail, beak and tongue, to climb the tree and secure vironment ; and of Lamarck,—the hereditary effects of use insects he was “ scientifically orthodox.” Nevertheless and disuse. Lyell for a long time hesitated to accept the he was led to believe in evolution, apart from any possible new teaching, and Darwin carried on a long correspondence motive-cause, by “ general facts in the affinities, embryology, with him. His public confession of faith was made at the rudimentary organs, geological history, and geographical Anniversary Dinner of the Royal Society in 1864. A distribution of organic beings.” He then proceeds to de- storm of controversy arose over the book, reaching its scribe the manner in which he met the difficulty of adapta- height at the meeting of the British Association at Oxford tion by “his notions on the means by which Nature makes in I860, when the celebrated duel between Huxley and her species.” The essentials of the statement are as the Bishop of Oxford took place. Throughout these follows :—I. Man has made his domestic breeds of animals struggles Huxley was the foremost champion for evolution and plants by selection, conscious or unconscious, of very and°for fair play to natural selection, although he never slight or greater variations. II. The material for selection entirely accepted the latter theory, holding that until man exists in nature, namely, slight variations of all parts, of by his selection had made his domestic breed sterile inter the organism. III. The “unerring power” which sifts se, there was no sufficient evidence that selection accounts these variations is Natural Selection . . . which selects for natural species which are thus separated by the barrier exclusively for the good of each organic being.” The rate of sterility. The theory of natural selection vas at first of increase is such that only a few in each generation can greatly misunderstood. Thus some writers thought it live: hence the never sufficiently appreciated struggle for implied conscious choice in the animals themselves, others life. “What a trifling difference must often determine that it was the personification of some active power. By which shall survive and which perish ! ” The remaining many it was thought to be practically the same idea as heads explain the complex nature of the struggle, the Lamarck’s. Herbert Spencer’s alternative phrase, “the reasons for deficient direct evidence, the advantage of survival of the fittest,” probably helped to spread a clear divergence, &c. In the Joint Essay the phrases “ Natural appreciation of Darwin’s meaning. The history of opinion since 1859 may be summed up Selection ” and “ Sexual Selection ” were first made public as follows. Evolution soon gained general acceptance, by Darwin, the “struggle for existence” by Wallace. Darwin and Wallace had only met once before the depart- except among a certain number of those of middle or more ure of the latter for the East. Their rivalry in the dis- advanced age at the time when the Origin appeared. covery of the great principle of Natural Selection was the Although natural selection had been an essential force in beginning of a lifelong friendship. Wallace was lying ill producing this conviction, there gradually grew toup a the with intermittent fever at Ternate in February 1858, when tendency to minimize its importance in relation he began to think of Malthus’s Essay, read several years causes originally suggested by Buffon and Lamarck, which before : suddenly the idea of the survival of the fittest were ably presented and further elaborated by Herbert flashed upon him. In two hours he had “thought out Spencer. In America a school of Neo-Lamarckians apalmost the whole of the theory,” and in three evenings peared, and for a time flourished under the inspiration of had finished his essay. Darwin, also inspired after reading the vigorous personality of E. D. Cope. The writings of Malthus, in October 1838, did not publish until nearly August Weismann next raised a controversy over the scope twenty years had elapsed, and then only when Wallace of heredity, assailing the very foundation of the hypotheses sent him his essay. Canon Tristram was the first to apply of Buffon, Lamarck, and Herbert Spencer by demanding
