Page:The Zoologist, 4th series, vol 4 (1900).djvu/363

Rh Among the instances quoted by Mr. Distant as bearing on the suggestion that "Even the obscure problem of the colouration of mankind may have originally—and before migration became such an important factor in modification—been due to a more or less assimilative colouration," are some remarks (p. 398) on the natives of Mashonaland from a paper by the late Mr. W. Eckersley, whose acquaintance I made when he visited this country seven years ago. In one portion of his paper Mr. Eckersley states that "large areas of red soil are frequently met with"; in quite another part he mentions that the colour of the Mashonas is "dark chocolate-brown, some shades removed from black." As a matter of fact, the absolute proportion of red soil in Mashonaland is comparatively small, and, moreover, the vast majority of the Kafirs live on the huge outcrops of granite which constitute the great bulk of the plateau. But, quite apart from this, any argument for the hypothesis of assimilative colouration, based on the relation of the Mashonas, or indeed any of the Bantu tribes, to the soil they now inhabit, is entirely vitiated by the fact that we know that these tribes have come down from the North comparatively recently, and some of their migrations, at least, have taken place within historic times. I certainly cannot agree with Mr. Distant's somewhat sweeping assertion that "the colour of mankind can in no sense come under the explanations of protective or aggressive resemblance..... or nuptial colouration." Any one who has seen a Kafir in his native bush must have been struck by his incouspicuousness as compared with a white man, and there can be little doubt that this assimilation to his surroundings must be of considerable value for aggressive purposes (as, for instance, in stalking game which might frequently be of vital importance); further, Darwin himself has argued ('Descent of Man,' ed. 2, p. 604) that racial colouring may be to some extent due to sexual selection.

Unfortunately, suggestions of the type referred to above are only too easily made, and might readily be multiplied with a little ingenuity. For instance, we might suggest that, as swallows are eminently aërial birds, the great predominance of blue in their colouring is due to continual exposure to the blue sky, and we might seek for confirmation of this in the fact that the blue colour is principally found on the upper surface, which is most exposed to this influence; and, finally, we should pass over in silence the little difficulty as to the colouring of the Swifts.