I know not how it may appear to others, but to me the parallelism between the Platonic and the Darwinian theory is very striking. Both speculators assume the existence of a Supreme Intelligence and Power, presiding over the creation of animals which are to inhabit this earth. Behind the celestial or primitive gods the Greek philosopher places the Demiurgus, to whom the gods stand in the relation of ministers or servants to execute his will. The modern naturalist assumes the existence of the Omnipotent God; and although he does not directly personify the laws of natural and sexual selection which the Omnipotent power has made to operate in nature, they perform an office in the transitional gradations through which the animals are successively developed, that very closely resembles the office performed by the gods of Plato's system in providing the modifications of structure which the animals undergo. In the two processes the one is the reversed complement of the other. Plato begins with the formation of an animal of a very exalted type, and by successive degradations, induced by the failure of the animal to live up to the high standard of its rational existence, he supposes a descent into lower and still lower forms, the gods all the while providing a new structure for each successive lower form, until we reach the shell-fish fixed on the earth beneath the water. Darwin begins with the lowest form of animated organization, and by successive gradations induced by the struggle of the animal to maintain its existence, he supposes an ascent into higher and still higher forms, the laws of natural and sexual selection operating to develop a new structure for each successive higher form, until we reach man, "the wonder and glory of the universe," an animal whose immediate ancestor was the same as the monkey's, and whose remote progenitor was an aquatic creature breathing by gills and floating by a swim-bladder.