ABSTRACT
All the secondary sexual characters of man are highly variable, even within the limits of the same race; they differ much in the several races. The development of the beard and the hairiness of the body differ remarkably in the men of distinct races, and even in different tribes or families of the same race. Throughout the great American continent the men may be said to be beardless; but in almost all the tribes a few short hairs are apt to appear on the face in old age. With the tribes of North America, G. Catlin estimates that eighteen out of twenty men are completely destitute by nature of a beard. With respect to differences of the mental powers between man and woman, it is probable that sexual selection has played a highly important part. Amongst the half-human progenitors of man, and amongst savages, there have been struggles between the males during many generations for the possession of the females.
