“On the other hand, mutilations and other effects of directly transforming agents are rarely, if ever, transmitted.” Professor Ray Lankester ought to know the facts better than to say that the effects of mutilation are rarely, if ever, transmitted. The rule is, that they will not be transmitted unless they have been followed by disease, but that where disease has supervened they not uncommonly descend to offspring. {234a} I know Brown-Séquard considered it to be the morbid state of the nervous system consequent upon the mutilation that is transmitted, rather than the immediate effects of the mutilation, but this distinction is somewhat finely drawn. When Professor Ray Lankester talks about the “other effects of directly transforming agents” being rarely transmitted, he should first show us the directly transforming agents. Lamarck, as I have said, knows them not. “It is little short of an absurdity,” he continues, “for people to come forward at this epoch, when evolution is at length accepted solely because of Mr. Darwin’s doctrine, and coolly to propose to replace that doctrine by the old notion so often tried and rejected.” Whether this is an absurdity or no, Professor Lankester will do well to learn to bear it without showing so much warmth, for it is one that is becoming common. Evolution has been accepted not “because of” Mr. Darwin’s doctrine, but because Mr. Darwin so fogged us about his doctrine that we did not understand it. We thought we were backing his bill for descent with modification, whereas we were in reality backing it for descent with modification by means of natural selection from among fortuitous variations. This last really is Mr. Darwin’s theory, except in so far as it is also Mr. A. R. Wallace’s; descent, alone, is just as much and just as little Mr. Darwin’s doctrine as it is Professor Ray Lankester’s or mine. I grant it is in great measure through Mr. Darwin’s books that descent has become so widely accepted; it has become so through his books, but in spite of, rather than by reason of, his doctrine. Indeed his doctrine was no doctrine, but only a back-door for himself to escape by in the event of flood or fire; the flood and fire have come; it remains to be seen how far the door will work satisfactorily.