The total number of human individuals at present amounts to between 1,300 and 1,400 millions. In our Tabular Survey (p. 333) 1,350 millions has been assumed as the mean number. According to an approximate estimate, as far as such a thing is possible, 1,200 millions of these are straight-haired men, only about 150 millions woolly-haired. The most highly developed species, Mongols and Mediterranese, far surpass all the other human species in numbers of individuals, for each of them alone comprises about 550 millions. (Compare Friederich Müller’s Ethnography, p. 30.) Of course the relative number of the twelve species fluctuates every year, and that too according to the law developed by Darwin, that in the struggle for life the more highly developed, the more favoured and larger groups of forms, possess the positive inclination and the certain tendency to spread more and more at the expense of the lower, more backward, and smaller groups. Thus the Mediterranean species, and within it the Indo-Germanic, have by means of the higher development of their brain surpassed all the other races and species in the struggle for life, and have already spread the net of their dominion over the whole globe. It is only the Mongolian species which can at all successfully, at least in certain respects, compete with the Mediterranean. Within the tropical regions, Negroes, Kaffres, and Nubians, as also the Malays and Dravidas, are in some measure protected against the encroachments of the Indo-Germanic tribes by their being better adapted for a hot climate; the case of the arctic tribes of the polar regions is similar. But the other races, which as it is are very much diminished in number, will sooner or later completely succumb in the struggle for existence to the superiority of the Mediterranean races. The American and Australian tribes are even now fast approaching their complete extinction, and the same may be said of the Papuans and Hottentots. In now turning to the equally interesting and difficult question of the relative _connection_, _migration_, and _primæval home_ of the twelve species of men, I must premise the remark that, in the present state of our anthropological knowledge, any answer to this question must be regarded only as a provisional hypothesis. This is much the same as with any genealogical hypothesis which we may form of the origin of kindred animal and vegetable species, on the basis of the “Natural System.” But the necessary uncertainty of these special hypotheses of descent, in no way shakes the absolute certainty of the general theory of descent. Man, we may feel certain, is descended from Catarrhini, or narrow-nosed apes, whether we agree with the polyphylites, and suppose each human species, in its primæval home, to have originated out of a special kind of ape; or whether, agreeing with the monophylites, we suppose that all the human species arose only by differentiation from a single species of primæval man (Homo primigenius).