We will now give a summary of the present chapter. In face of the difficulties offered by the most liberal interpretation of the Biblical text, and the objection founded on the law regulating the generation of hybrids, it is impossible to pronounce categorically in favour of a multiplicity of origin for the human species. We must therefore be content to assign a lower cause to those clear-cut varieties of which the main quality is undoubtedly their permanence, a permanence that can only be lost by a crossing of blood. We can identify this cause with the amount of climatic energy possessed by the earth at a time when the human race had just appeared on its surface. There is no doubt that the forces that inorganic nature could bring into play were far greater then than anything we have known since, and under their pressure racial modifications were accomplished which would now be impossible. Probably, too, the creatures exposed to these tremendous forces were more liable to be affected by them than existing types would be. Man, in his earliest stages, assumed many unstable forms; he did not perhaps belong, in any definite manner, to the white, red, or yellow variety. The deviations that transformed the primitive characteristics of the species into the types established to-day were probably much smaller than those that would now be required for the black race, for example, to become assimilated to the white, or the yellow to the black. On this hypothesis, we should have to regard Adamite man as equally different from all the existing human groups; these would have radiated all around him, the distance between him and any group being double that between one group and another. How much of the primitive type would the peoples of the different races have subsequently retained? Merely the most general characteristics of our species, the vague resemblances of shape common to the most distant groups, and the possibility of expressing their wants by articulate sounds—but nothing more. The remaining features peculiar to primitive man would have been completely lost, by the black as well as the non-black races; and although we are all originally descended from him, we should have owed to outside influences everything that gave us our distinctive and special character. Henceforth the human races, the product of cosmic forces as well as of the primitive Adamic stock, would be very slightly, if at all, related to each other. The power of giving birth to fertile hybrids would certainly be a perpetual proof of original connexion; but it would be the only one. As soon as the primal differences of environment had given each group its isolated character, as a possession for ever—its shape, features, and colour—from that moment the link of primal unity would have been suddenly snapped; the unity, so far as influence on racial development went, would be actually sterile. The strict and unassailable permanence of form and feature to which the earliest