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Page:Popular Science Monthly Volume 35.djvu/722

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THE recently published work of Mr. Alfred Russel Wallace on "Darwinism" furnishes a timely and weighty answer to those who, following the rash lead of the Duke of Argyll, have lately been maintaining that the doctrine of natural selection is wholly unable to explain the development of species, and that, as a theory, it has had its day. Far from conceding anything to this noisy school, Mr, Wallace is disposed to make even larger claims for the potency of this principle than Darwin himself did, and certainly larger than Mr. Spencer is to-day disposed to allow. He holds that we only have to look closely enough at the facts in order to see the Influence of natural selection every-where, and to convince ourselves that it alone has presided over the whole development of vegetable and animal forms. It is needless to say that Mr. Wallace is a naturalist of the very first rank, and that his reasonings do not lack for facts and illustrations to enforce them. The work he has now given to the world in an exceedingly valuable repertory of information bearing on the questions he discusses, and is written in a style at once popular and exact. In giving it the title "Darwinism," he once more evidences the generosity of nature which led him thirty years ago to waive the claims he might have urged as discoverer of the principle of the variation of species by means of natural selection. He recognizes that Darwin has made that whole field of investigation peculiarly his own; and he is, therefore, very willing that Darwin's name should stand indissolubly and exclusively connected with the great revolution in speculative biology which our generation has witnessed.

The two principal questions which Mr. Wallace's work will bring into prominence are (1) whether the extremely wide claims he puts forth on behalf of natural selection are fully made good; and (2) whether his views in regard to the mode of development of man's higher intellectual and moral nature are well founded. Upon the first point, as we have already hinted, Mr. Wallace comes into direct collision with Mr. Spencer. The latter considers that the doctrine of natural selection can not account for certain cases of variation, and that we must have recourse to the supplementary doctrine of use and disuse. Mr. Wallace takes up the instances cited by Mr. Spencer, and endeavors to show that they may be explained without calling in any other law than that of natural selection. He admits that, as regards those "lower organisms which consist of simple cells and formless masses of protoplasm," the action of the environment is very marked, and that the variations it produces on individual forms may be transmitted by inheritance; but he does not consider that we can argue from cases in which the environment acts thus powerfully on the whole life of the organism, and, of course, necessarily on its reproductive system, so far as it can be said to have a system, to cases where the outward structure alone of well-established types is affected by change of habit. Such modifications he does not think are transmissible by inheritance; spontaneous variation and natural selection alone are adequate, in his opinion, to produce permanent variation. The question is manifestly an obscure one, calling for patient and exhaustive investigation. If changes produced by the environment in the very lowest forms may be transmitted by inheritance, as Wallace admits, then the