Chap. IV. MANNER OF DEVELOPMENT. 149 



their hairy covering from exposure to heat. This appears 

 the more probable, as the elephants in India which live 

 on elevated and cool districts are more hairy 77 than those 

 on the lowlands. May we then infer that man became 

 divested of hair from having aboriginally inhabited some 

 tropical land ? The fact of the hair being chiefly 

 retained in the male sex on the chest and face, and in 

 both sexes at the junction of all four limbs with the 

 trunk, favours this inference, assuming that the hair was 

 lost before man became erect ; lor the parts which now 

 retain most hair would then have been most protected 

 from the heat of the sun. The crown of the head, 

 however, offers a curious exception, for at all times it 

 must have been one of the most exposed parts, yet 

 it is thickly clothed with hair. In this respect man 

 agrees with the great majority of quadrupeds, which 

 generally have their upper and exposed surfaces more 

 thickly clothed than the lower surface. Nevertheless, 

 the fact that the other members of the order of Pri- 

 mates, to which man belongs, although inhabiting vari- 

 ous hot regions, are well clothed with hair, generally 

 thickest on the upper surface, 78 is strongly opposed 

 to the supposition that man became naked through the 

 action of the sun. I am inclined to believe, as we 

 shall see under sexual selection, that man, or rather 

 primarily woman, became divested of hair for orna- 

 mental purposes ; and according to this belief it is not 



77 Owen, l Anatomy of Vertebrates,' vol. iii. p. 619. 



78 Isidore Geoffroy St.-Hilaire remarks (' Hi§t. Nat. Generale,' torn, 

 ii. 1859, p. 215-217; on the head of man being covered with long hair ; 

 also on the upper surfaces of monkeys and of other mammals being 

 more thickly clothed than the lower surfaces. This has likewise been 

 observed by various authors. Prof. P. Gervais ( ' Hist. Nat. des Mam- 

 miferes,' torn. i. 1854, p. 28), however, states that in the Gorilla the 

 hair is thinner on the back, where it is partly rubbed off, than on the 

 lower surface. 



