30 ANIMAL DENTISTRY. 



ing — the apical foramen — for the entrance of blood vessels 

 and nerves. 



In situ they are arranged in perfect juxtaposition in the 

 form of a symmetrical curve w^ith the convexity forward, 

 and their contact with the opposing arcade is at an obtuse 

 angle. Near the gingival margin they are separated by 

 processes of the gums. (See Fig. lo.) 



The function of the incisor teeth is that of detaching food 

 that has been gathered by the lips, and to serve as weapons 

 of defense. They are not concerned in mastication. For 

 changes in the teeth, see Chapter III. 



THE CANINE TEETH OF THE HORSE. 



The canine teeth exist only in males and occur only as 

 permanent teeth. They occur occasionally as rudimentary 

 structures in the mare, but never develop the typical canine 

 characteristics. They represent a curved tube about one 

 centimeter in diameter, and flattened at one end — the crown. 

 The crown is flat and presents internally two shallow per- 

 pendicular grooves divided by a rounded ridge. The fang 

 is cylindrical and the apical foramen round and large. 



The canines, so far as digestion is concerned, are use- 

 less members which the horse could well do without. They 

 are probably intended as weapons of defense, and may serve 

 to assist in passing coarse fibrous food from the incisors to 

 the molars. 



THE MOLARS. 



The superior molars resemble an elongated square block 

 tapering slightly toward one extremity. They present for 

 description four surfaces, the table and apex. The external 

 or buccal surface presents three prominent longitudinal 

 ridges separated by two grooves, all of which traverse the 

 entire length of the tooth, and terminate at the table in a 



