which alone have any power; on the other, activity, spontaneous power of adaptation and transformation, the relative freedom of all things living, and—the deepest answer to the question of the controlling force in evolution—_the secret of life_. This last contrast goes deeper even than the one we have already noted, that between the Darwinian and the Lamarckian principle of explanation; and it leads ultimately from the special Darwinian problem to quite a new one, to be solved by itself—the problem of the nature and secret of living matter. Weismannism. In regard to almost all the points to which we have referred, the most consistent and decided champion of Darwinism in its essential principles is the zoologist of Freiburg, August Weismann.(35) In long chapters on the protective coloration of animals, on the phenomena of mimicry—that resemblance to foreign objects (leaves, pieces of wood, bark, and well-protected animals) by which the mimics secure their own safety from enemies—on the protective devices in plants, the selective value of “the useful” is demonstrated. In regard to the marvellous phenomena of “carnivorous” plants, the still more marvellous instincts of animals, which cannot be interpreted on Lamarckian lines as “inherited habit,” but only as due to the cumulative influence of selection on inborn tendencies, as well as in regard to “symbiosis,” “the origin of flowers,” and so on, he attempts to show that the heterodox attempts at explanation are insufficient, and that selection alone really explains. At the same time the Darwinian principle is carried still further. It is not only among the individuals, the “persons,” that the selective struggle for existence goes on. Personal selection depends upon a “germinal selection” within the germ-plasm, influencing it, and being influenced by it—for instance, restrained.