4 THE STRUCTURE OF MAN 



mentioned, hair is frequently strongly developed on the ventral 

 and dorsal regions of the trunk, i.e. on the breast and abdomen, 

 and on the buttocks and neck, and on the limbs. 



These facts alone would suffice to render it probable that 

 man was in primitive times far more hairy than at present, but 

 still stronger evidence can be brought forward. 



FIG. 1. FACE OF AN EMBRYO FIVE MONTHS OLD, with the embryonic covering 

 of hair. (After Ecker.) 



The first traces of hair appear, in the human embryo, as early 

 as the twelfth or thirteenth week, the earliest being found about 

 the forehead, the mouth, and the eyebrows, i.e. in those parts of 

 the body where, in the lower Mammals, the so-called " whiskers " 

 (vibrissse) or tactile hairs usually appear. It is evident that, 

 morphologically, the hairs about the mouth and eyebrows in Men 

 belong to this same category. The hairs begin to break through 

 the integument at the end of the fifth month, and they con- 

 tinue to do so till the seventh month, those of the head being the 

 earliest and those of the limbs the latest to appear. 1 In the 



1 The fact of the appearance of hair in different parts of the body in regular 

 order, the lower limbs being the last to become thus clothed, has apparently attained 

 popular recognition in the very old proverb "he has hair on his toes," which may 

 doubtless be referred to a time when boots and shoes did not play the part they now 

 do. From what I have gathered in conversation with inhabitants of Berne (Ober- 



