OUR FACE FROM FISH TO MAN 



shifting of the eyes toward the front of the head. 

 The muzzle, or olfactory chamber, is not yet 

 reduced. 



The still surviving primates afford a remarkably 

 well graded series of faces, from the fox-like face 

 of Lemur (Fig. 34A) to the quaint old-man-like 

 faces of some of the Old World monkeys (Fig. 34C). 

 In the lower forms {Lemur, etc.) a rhinarium, or 

 moist patch, is present at the tip of the long snout, 

 the opposite lips are separated by a notch in the 

 mid-line and lack the mobility seen in the higher 

 forms. In the latter, with the shortening of the 

 muzzle, the rhinarium gives place to a true nose, 

 the mucous-secreting skin being limited to the 

 inner side of the nostrils and the nose eventually 

 growing out between the nostrils. Meanwhile the 

 opposite upper lips have become more broadly 

 joined at the mid-line and finally the lips become 

 highly protrusile through the constricting action 

 of the strong orbicularis oris muscle. 



In the New World, or platyrrhine, monkeys 

 (Fig. 34B), which appear to represent an independ- 

 ent offshoot from some primitive tarsioid stock, 

 the nostrils are widely separated, opening out- 

 wardly on each side of the broad median part of 



56 



