It is true that assimilative colouration seems to have little modified the colour of indigenous races, even in Africa, if we take a comprehensive view of the whole area. But we must not forget that men have so often migrated from their original birthplaces, and more than that, much mixture has taken place. Emin Pasha remarks on "the intermingling of separate tribes and peoples in Central Africa consequent upon war, plundering raids, dividing of the spoil in women, slavery and exchange of slaves, and in a much less degree on intermarriage"; and further, "that it is almost impossible to obtain skulls of really pure race." He also observes: "Whether the great variation in the colour of the skin observable among all Negro tribes is to be attributed to these mixed relationships, I do not venture yet to decide."[1]
The relationship between the surface hue of the geological floor on which the primary races of men may have developed their individuality of colour, and the prevalent tints of those races, has been little studied, though that investigation might also throw much light on the areas where racial segregation established those divisions which in any other group of animals would at least be considered specific. Even in our own country this old connection between land and man has been pointed out by the late Prof. Ramsay: "Thus it happens that the oldest tribes now inhabiting our country are to be found among the old palæozoic mountains, which, composed of the most ancient of our geological formations, and rising up into the highest grounds, must have been the first parts of the British islands to rise above the waters during the last elevation of the land."[2] This observation is doubtless capable of more universal application, and human assimilative colouration might prove a reasonable hypothesis if we could only trace the early dispersal of our species in a scientific manner and spirit, without the aid of a Hebraistic "Tower of Babel," or the view once advanced by ethnologists of a Caucasian nursery based on a still earlier attempt to locate the "Garden of Eden." The boldest of new theories are at least not more grotesque than the explanations of quite recent times, and whereas the last were believed to be final, the first are advanced only as propositions for future verification or
