immense and indefinable degree of divergence, on the part of the descendants of a given pair, from the characters of their ancestors. As Kant himself observed, it assigned many of the species of the systematists to a common descent. But if the "reproductive faculty" of the primeval wolf was—as Kant grants that it may have been—capacious enough to contain special "germs" for the subsequent production, not only of wolves, but also of jackals, pug-dogs, greyhounds, dachshunds, hyenas and bull-dogs, there appeared to be no adequate reason for assigning any particular limit to the original capacity, and the consequent eventual versatility, of that faculty in any organism whatever. It was entirely open to Kant, without abandoning his theory of anticipatory germs, to regard the wolf in turn as the development of a germ implanted in still earlier ancestors, which the wolf and his diverse present progeny share in common with a group of organisms still more various; and so on ad indefinitum. Since the immutability of "nature's original model" was to be sufficiently salved by the simple devi'ce of supposing that model to have virtually contained within itself, and in course of time, under changing external conditions, to have extruded from itself, a vast assortment of other extremely dissimilar models, there was nothing in the most thorough-going theory of the transformation of species which could be inconsistent with an immutability of so elusive and so elastic a character. Kant's rejection of evolutionism was thus not justified even by those singular embryological speculations into which his desire to reject that theory seduced him.
4. The Review of Herder's "Ideen."—In 1785 Kant published a review of Herder's "Ideen zu einer Philosophie der Geschichte der Menschheit." Herder, as I have elsewhere shown, was not a believer in the transformation of species; but he may perhaps be without exaggeration described as a near-evolutionist. He set forth in the "Ideen" the theory of a gradual production of organisms in an ascending series in which little by little the form and powers of man were approximated. Through all this "graded scale of beings" was conspicuous that "unity of type" which the work of Daubenton and Buffon in comparative anatomy had brought to light. The successive emergence of ever higher forms Herder ascribed to some innate potency in "nature" tending to progress and to the constant increase and diversification of life. Just how he conceived this to operate in the actual formation of organisms it seems impossible to make out; one is obliged to doubt whether he ever framed any definite ideas on the subject. But on the unity, yet inexhaustible diversity, of nature's productive power, and on the strange way in which, as he supposed, all animals and plants, and perhaps even snow-flakes and other inorganic things, are fashioned after a single archetype of form. Herder had much to say that was eloquent and impressive, if not very clear. In
- Popular Science Monthly, August, 1904, p. 327.