THE DESCENT OF MAN. 



secondary sexual character; for in all parts of the world 

 women are less hairy than the men. Tlierefore we may 

 l*easonably suspect that this character has been gained 

 through sexual selection. We know that the faces of 

 several species of monkeys, and large surfaces at the 

 posterior end of the body of other species, have been 

 denuded of hair; and this we may safely attribute to 

 sexual selection, for these surfaces are not only vividly 

 colored, but sometimes, as with the male mandrill and 

 female rhesus, much more vividly in the one sex than in 

 the other, especially during the breeding-season. I am 

 informed by Mr. Bartlett that, as these animals gradually 

 reach maturity, the naked surfaces grow larger compared 

 with the size of their bodies. The hair, however, appears 

 to have been removed, not for the sake of nudity, but that 

 the color of the skin may be more fully displayed. So, 

 again, with many birds, it appears as if the head and neck 

 had been divested of feathers, through sexual selection, to 

 exhibit the brightly colored skin. 



As the body in woman is less hairy than in man, and as 

 this character is common to all races, we may conclude 

 that it was our female semi- human ancestors who were first 

 divested of ha'r, and that this occurred at an extremely re- 

 mote period before the several races had diverged from a 

 common stock. While our female ancestors were gradually 

 acquiring this new character of nudity they must have 

 transmitted it almost equally to their offspring of both 

 sexes while young; so that its transmission, as with the 

 ornaments of many mammals and birds, has not been 

 limited either by sex or age. There is nothing surprising 

 in a partial loss of hair having been esteemed as an orna- 

 ment by our ape-like progenitors, for we have seen that in- 

 numerable strange characters have been thus esteemed by 

 animals of all kinds and have consequently been gained 

 through sexual selection. Nor is it surprising that a 

 slightly injurious character should have been thus acquired; 

 for we know that this is the case with the plumes of certain 

 birds, and with the horns of certain stags. 



The females of some of the anthropoid apes, as stated in 

 a former chapter, are somewhat less hairy on the under 

 surface than the males; and here we have what might have 

 afforded a commencement for the process of denudation. 

 With respect to the completion of the process through 



