THE TEETH OF RODENTIA. 



369 



remains of the pulps are converted into secondary or osteo- 

 dentine, which thus forms the central axis of the incisors, or 

 molars, as the case may be. In this tissue vascular tracts 

 sometimes exist, but it is altogether small in amount, the 



Fro. 159 ('). 



formation of true dentine going on till the pulp at that 

 particular point is almost obliterated. 



As has already been mentioned, when the molar series 

 consists of more than three teeth, those anterior to the 

 three true molars are premolars, which have displaced milk 

 teeth ; but they do not differ materially in size or form from 

 the true molars. 



The form of the condyle and of the glenoid cavity in 

 Kodents are characteristic ; they are much elongated in an 

 antero-posterior direction, so that the range of backward 



(t) Condyle and glenoid cavity of the Capybara, showing their longitu- 

 dinal direction. 



R B 



