But to return to the degeneration of beings, and particularly to that of animals. Let us examine more nearly still, the steps of nature, in the variety which she offers to our view; and, as the human species is best known to us, let us observe how far these steps of variation extend. Men differ in colour from black to white, they differ also one half in their height, bulk, lightness, strength, &c. and above all in their understandings; but this last quality having nothing to do with matter, ought not to be considered here. The others are the usual variations of nature, proceeding from the influence of climate and food; but, these differences of size and colour do not prevent the Negro and the White, the Laplander and Patagonian, the Giant and Dwarf, from mixing together, and producing fertile individuals; and consequently these men, so different in appearance, are all of one species, since this constant reproduction is that which constitutes distinct species. Besides these general variations, there are others more particular, which are also perpetrated; such as the enormous legs of the men who are called of the race of St. Thomas, in the island of Ceylon; the red eyes and white hair of the Dariens and Chacrelas, the six fingers and toes in certain families, &c. These singular varieties are either accidental defaults or excesses, which originating in some individuals, are propagated from race to race, like hereditary defects and diseases; but these differences should not be regarded as forming separate species, since the extraordinary races of these men with large legs, or six fingers, may mix with the ordinary races, and produce fertile individuals. The same thing may be said of all other deformities communicated from parents to their children. Thus far the errors of Nature, and the varieties among men extend, and if there are individuals which degenerate still more, those individuals reproducing nothing, neither alter the constancy nor uniformity of the species. Thus man constitutes but one and the same species, and, though this species is perhaps more numerous, inconstant, and irregular in all its actions, yet the prodigious diversity of nourishment, climate, and so many other combinations as may be supposed, have not produced beings different enough from each other to constitute new species, and at the same time so like ourselves, that we are not able to deny but that we are of the same race.