INTRODUCTION. 



the condyle plays ; but the freedom of the articulation does not appear 

 to be increased : indeed, the overpassing of the canines (of which the 

 lower are received into a space between the upper canines and the 

 incisors), would of itself interfere with a very free lateral grinding 

 movement. The muscles acting on the lower jaw are far more power- 

 ful than in Man : in the Orang their volume is immense ; and the 

 teeth of the Simiae are far larger and stronger in proportion : the incisors 

 are well adapted for the rough work of stripping off the husks of fruits ; 

 the molars, for masticating hard seeds, and other vegetable matters ; while 

 the canines are formidable weapons. 



In the Carnivora, the articulation of the lower jaw is in character with 

 their dentition, and, therefore, very different from that of the human 

 subject, or the Simiae. On examining the skull of the Tiger, or Wolf, 

 we are struck with the boldness and strength of the zygomatic process of 

 the temporal bone, which starts out abruptly, at a right angle with the 

 side of the cranium, and then turns forward to unite with the zygo- 

 matic process of the malar bone. On the under surface of the base of the 



124 



125 



Pig. 124. A lateral view of the articulrtttug 1 etmdyle of the lower jaw in the Tiger, a, and of the glenoid cavity, It. 

 Fig. 125. Auother view, she wing- their surfaces. 



zygomatic process of the temporal bone is the glenoid cavity, b (fig. 125), 

 in the form of an elongated canal, with an elevated margin before and 

 behind, extending along that process till it assumes its forward bend; 

 and, consequently, transverse to the cranium. To fit this cavity, the con- 

 dyle of the lower jaw, a, is accurately formed : it is a long transverse pro- 

 cess, rounded above, appearing as though a smooth cylinder of bone had 

 been transversely joined to the posterior part of the ramus of the jaw. 

 In Man, and the Simiae, the articulating condyle is thrown to a consi- 

 derable distance from the posterior angle of the jaw, and is as elevated as 

 the coronoid process : indeed, it is more elevated in Man : but, in the 

 Carnivora it is seated at the base of the coronoid process, just above the 



