This is natural enough, for Mr. Wallace has entitled his book Darwinism, and a work denying that use and disuse produced any effect could not conceivably be called Darwinism.  Mr. Herbert Spencer has recently collected many passages from The Origin of Species and from Animals and Plants under Domestication,” {263} which show how largely, after all, use and disuse entered into Mr. Darwin’s system, and we know that in his later years he attached still more importance to them.  It was out of the question, therefore, that Mr. Wallace should categorically deny that their effects were inheritable.  On the other hand, the temptation to adopt Professor Weismann’s view must have been overwhelming to one who had been already inclined to minimize the effects of use and disuse.  On the whole, one does not see what Mr. Wallace could do, other than what he has done—­unless, of course, he changed his title, or had been no longer Mr. Wallace.

Besides, thanks to the works of Mr. Spencer, Professor Mivart, Professor Semper, and very many others, there has for some time been a growing perception that the Darwinism of Charles Darwin was doomed.  Use and disuse must either do even more than is officially recognized in Mr. Darwin’s later concessions, or they must do a great deal less.  If they can do as much as Mr. Darwin himself said they did, why should they not do more?  Why stop where Mr. Darwin did?  And again, where in the name of all that is reasonable did he really stop?  He drew no line, and on what principle can we say that so much is possible as effect of use and disuse, but so much more impossible?  If, as Mr. Darwin contended, disuse can so far reduce an organ as to render it rudimentary, and in many cases get rid of it altogether, why cannot use create as much as disuse can destroy, provided it has anything, no matter how low in structure, to begin with?  Let us know where we stand.  If it is admitted that use and disuse can do a good deal, what does a good deal mean?  And what is the proportion between the shares attributable to use and disuse and to natural selection respectively?  If we cannot be told with absolute precision, let us at any rate have something more definite than the statement that natural selection is “the most important means of modification.”

Mr. Darwin gave us no help in this respect; and worse than this, he contradicted himself so flatly as to show that he had very little definite idea upon the subject at all.  Thus in respect to the winglessness of the Madeira beetles he wrote:—­

“In some cases we might easily put down to disuse modifications of structure, which are wholly or mainly due to natural selection.  Mr. Wollaston has discovered the remarkable fact that 200 beetles, out of the 550 species (but more are now known) inhabiting Madeira, are so far deficient in wings that they cannot fly; and that of the 29 endemic genera no less than 23 have all their species in this condition!