far-reaching advantage, that instead of a long succession of wonders,—call them if you like the wonder of the monads, or the worm, or the mollusk, or the fish, or the amphibian, or the reptile, or the bird, or, lastly, man,—it has but one wonder before it, the Logos, the idea of thought, or of the eternal thinker, who thought everything that exists in natural sequence, and in this sense made all. In this view we need not even abandon the survival of the fittest, only it proceeds in the Logos, in the mind, not in the outward phenomenal world. It would then also become conceivable that the embryological development of animated nature runs parallel with the biological or historical, or as it were recapitulates it, only the continuity of the idea is far closer and more intimate than that of the reality. Thus, for instance, in the development of the human embryo, the transition from the invertebrate to the vertebrate may be represented in the reality by the isolated amphioxus, which remains stationary where vertebrate man begins, and can make no step forward, while the human embryo advances farther and farther till it reaches its highest limit. In order now to infer from these and similar facts that man at one time really existed in this scarcely vertebrate condition of the amphioxus,—a conclusion which, strictly understood, yields no meaning,—we can make the case much more easily conceivable if we represent the thinking, or invention of the world, as an ascending scale, in which even the least chromatic tone must have a place without a break, while the principal tones do not become clear and full until the requisite number of vibrations is attained. These gradations of tone are the really interesting thing in nature. As the full, clear tones imply certain numerical relations among the vibrations, so the successive stages or the true species in nature imply a will or thought in which the true _Origin of Species_ has its foundation. That natural selection, as it is called, could suffice to explain the origin of species, was doubted even by Huxley,(38) who yet described himself as Darwin’s bull-dog.