THE DESCENT OR ORIGllSr OF MAN 203 



verge from above and below to a point at tbe elbow. This 

 curious arrangement, so unlike that in most of the lower 

 mammals, is common to the gorilla, chimpanzee, orang, 

 some species of Hylobates, and even to some few American 

 monkeys. But in Hylobates agilis the hair on the forearm 

 is directly downward or toward the wrist in the ordinary 

 manner; and in H. lar it is nearly erect, with only a very 

 slight forward inclination ; so that in this latter species it is 

 in a transitional state. It can hardly be doubted that with 

 most mammals the thickness of the hair on the back and its 

 direction is adapted to throw off the rain; even the trans- 

 verse hairs on. the forelegs of a dog may serve for this end 

 when he is coiled up asleep. Mr. Wallace, who has care- 

 fully studied the habits of the orang, remarks that the con- 

 vergence of the hair toward the elbow on the arms of the 

 orang may be -explained as serving to throw off the rain, 

 for this animal during rainy weather sits with its arms bent, 

 and with the hands clasped round a branch or over its head. 

 According to Livingstone, the gorilla also "sits in pelting 

 rain with,his hands over his head." ° If the above explana- 

 tion is correct, as seems probable, the direction of the hair 

 on our own arms offers a curious record of our former state ; 

 for no one supposes that it is now of any use in throwing off 

 the rain; nor, in our present erect condition, is it properly 

 directed f^r this purpose. 



It woiild, however, be rash to trust too much to the prin- 

 ciple of adaptation in regard to the direction of the hair in 

 man or^^his early progenitors; for it is impossible to study 

 the figures given by Eschricht of the arrangement of the 

 hair'^n the human foetus (this being the same as in the adult) 

 and not agree with this excellent observer that other and 

 more coipiplex causes have intervened. The points of con- 

 vergencsi seem to stand in some relation to those points in 

 the embryo which are last closed in during development. 

 There appears also to exist some relation between the ar- 



_^-L 



•Quoted by Readej "The African Sketch Book," vol. i., 1873, p. 152. 



