CHAPTER III. 



THE PERMANENT DENTITION. 



Distinction between Premolars and Molars. — The Bow-like In- 

 cisors. — Contrasts between the Upper and Lower Grinders, 

 and the Rows formed by them. — The Incisors saved from 

 Friction. — Horsss' Teeth compared with those of other An- 

 imals. — Measurements. — Time's Changes. — Growth during 

 Life. 



The Permanent Teeth, owing to their increased size 

 and number, are as well adapted to the needs of the 

 horse as the temporary are to the foal. In the males 

 forty teeth are functionally developed ;* in the females 

 thirty-six, the latter, as a rule, having no canine teeth. 

 However, their rudiments exist in the jaws, and some- 

 times, especially in old age, protrude. Of the forty 

 teeth in the male horse there are twelve incisors, four 

 canines or tushes (also called cannon or bridle teeth), 

 twelve premolars,! and twelve molars. The dental 

 formula is expressed thus : 



L;|-|; 0.,i-{; P.M.,|-|; M.,f-|=40. 



* The teeth that are not functionally developed are treated of 

 in the chapter entitled "Remnant Teeth." 



f " Premolars are teeth in front of the molars ; they usually 

 differ from them by beiu^ smaller and more simple in form, and 

 in most animals have displaced deciduous predecessors. But 

 they are not always smaller nor simpler in form [e. g., the 



