98 ARBOREAL MAN 



the snout region as features of the head and face (see 

 Fig. 34). It is noteworthy that when for any reason 

 elongation of the nose becomes characteristic of any 

 species of monkey, this elongation is produced quite 

 apart from any reversion to a condition of prolonged 

 snout region. In the Proboscis Monkey (Nasalis larva- 

 1us) the nose reaches a remarkable degree of prominence, 

 but there is no involvement of the maxilla or mandible 

 in this new departure, and the same tendency is shown, 



FIG. 34. OUTLINE OF A HUMAN SKULL, TO SHOW THE RELATIVE 

 PORTIONS DEVOTED TO THE SKELETON OP THE FACE AND TO 

 THE SKELETON OF THE BRAIN CAVITY. 



but to a lesser degree, in the curious Snub-Nosed Monkey 

 (Ehinopithecus roxellance). 



These general alterations of the configuration of the 

 head and face lead to several changes, especially in the 

 position of the sense organs, which are probably of the 

 greatest importance. When an animal has a fully elon- 

 gated snout region, it may be said to possess a long face 

 with an eye situated upon each side of it ; but when the 

 snout region has undergone complete recession, it may 

 be said to have a flat face with two eyes situated upon 

 the front of it. The mere fact of the recession of the 

 snout produces this change, for the two eyes are turned 



