A large part of the life of the earth has remained steadfastly where it was cradled, beneath the waves. But more restless portions have left the sea and crept forth upon the land, or swarmed into the air. One migration, the most numerous, is represented by the insects. Another, the most enterprising, was the amphibian. After ages of evolution the amphibian branch divided. One branch acquired wings and sailed off into the air. The other divided and subdivided. One of these subdivisions entered the forests, climbed and clambered among the trees, acquired perpendicularity and hands, descended and walked upon the soil, invented agriculture, built cities and states, and imagined itself immortal. Human society is but the van—the hither terminus—of an evolutional process which had its beginning away back in the protoplasm of primeval waters. There is not a form that creeps beneath the sea but can claim kinship with the eagle. The philosopher is the remote posterity of the meek and lowly amoeba. 1. See ‘Genealogy of Animals,’ at the end of the chapter. 2. See table of geological ages, at the end of the previous chapter. XI. Conclusion. The resemblances, homologies, and metamorphoses existing everywhere among animal forms are, therefore, evidence of the most logical consanguinities. It is all so perfectly plain. The structures of organic beings have come about as a result of the action and reaction of environment upon these structures. Every being—and not only every being, but every species, the whole organic world—has come to be what it is as a result of the incessant hammerings of its surroundings, the hammerings not only of the present, but of the long-stretching past. By surroundings is meant, of course, the rest of the universe. Those animals belonging to the same stock resemble each other because they have been subjected to the same experiences, the same series of selections. They have lain on the same great anvil, and felt the down-comings of the same sledge. The similarities among animal forms in general indicate relationships, just as the similarities among the races of men indicate racial consanguinities. All men belong to the human species because they are all fundamentally alike. But there are differences in the character of the hair, in the colour of the skin, in the conformation of the skull, and in the structure of the language, among the different varieties of the species, indicating striking variety in relationship and origin. An eminent biologist has said that if Negroes and Caucasians were snails they would be classed as entirely distinct species of animals. Whether, as is thought by some, the woolly-haired races are the descendants of the African anthropoids, and the straight-haired varieties are the posterity of the orangs and gibbons, we may never know positively. But we do know that these two great branches of mankind must have different genealogies, extending to a remote antiquity, and that the varieties