HABITS AND HAIR OF PRIMATES 107 



many hours oi rest, and I doubt if the number of hours thus spent 

 by these and other wild animals to that spent in active exercise is 

 less than three to one, so that their attitudes of rest would, if 

 calculated to do so, contribute much towards any change occurring 

 in the patterns of hair. But, seeing that the ape-fashion is similar 

 to that of the lemur, and that this normal arrangement is calculated 

 only to be confirmed by the action of gravity and the dripping 

 of rain, and that they do not greatly indulge themselves, if at all, 

 in their equivalent for man's armchairs, nothing else would be 

 expected in the hairy covering of their backs than what we find. 



The increasing tendency to the upright position in Eoantbropus 

 Dawsoni and Pithecanthropus Erectus to say nothing of the men 

 of Cromagnon — led man to use as supports for bis back the walls of 

 his rough caves which he had adopted as dwellings instead of the 

 branches of trees and the nests of the ape. He no longer affected 

 entirely those hardy habits of sitting without support for his 

 back that were de rigueur in his ancestors, who probably looked 

 upon him with as much disapproval as certain erect old ladies of 

 the old school display towards the use of easy chairs by the rising 

 generation. Wearied with the struggle for food, and against his 

 savage rivals, he rested his back against the sides of his rude abode. 

 When he slept in this attitude the relaxation of his voluntary 

 muscles allowed mechanical forces to come into action which tended 

 to oppose the downward trend of the hair. We know from our 

 own experience that when sitting asleep with our backs supported 

 there always occurs a certain amount of sinking down of the trunk. 

 In this attitude are present, then, such conditions of the back and 

 its hairy covering as give rise to mechanical forces which would 

 interfere with the direction of the hair. These are, a heavy body, 

 tending to slip downwards slightly while resting against a fixed 

 surface, a growing tissue easily diverted from its normal course, 

 and many hours spent in the attitude in question. 



The effects of these conditions increased with the increasing 

 tendency of developing man to attend to his bodily comfort. 



But man spends also on the average at least a third of his 

 whole existence lying in sleep with his head on a pillow of some 

 kind, perhaps the skull of a Felis Groeneveldtii in the case of 

 Pithecanthropus Erectus, and other such better objects, as he made 

 more study of the art of being comfortable. Those who know much 

 of children and sick persons and have watched them in sleep know 

 that the habit of lying on one or other side prevails largely over 

 that of lying on the back. The head being more or less raised by a 

 pillow, the human sleeper, even when lying on his back and more 



