130 THE VITAL FUNCTIONS. 



In the conformation of the teeth and jaws, a re- 

 markable contrast is presented between carnivorous 

 and herbivorous animals. In the former, of which 

 the Tiger, Fig. 274, may be taken as an example, 

 the whole apparatus for mastication is calculated 



for the destruction of life, and for tearing and di- 

 viding the fleshy fibres. The molar teeth are 

 armed with pointed eminences, which correspond 

 in the opposite jaws, so as exactly to lock into one 

 another, like wheelwork, when the mouth is closed. 

 All the muscles which close the jaw are of enor- 

 mous size and strength ; and they imprint the bones 

 of the skull with deep hollows, in which we trace 

 marks of the most powerful action. The temporal 

 muscles occupy the whole of the sides of the skull 

 (t, t) ; and by the continuance of their vigorous 

 exertions, during the growth of the animal, alter so 

 considerably the form of the bones, that the skulls of 

 the young and the old animals are often with difii- 

 culty recognised as belonging to the same species.* 

 The process of the lower jaw (seen between t and 

 t), to which this temporal muscle is attached, is 



* This is remarkably the case with the Bear, the skull of which 

 exhibits in old animals a large vertical crest, not met with at an 

 early period of life. 



