620 THE EXTERIOR OF THE HORSE. 



root. Almost similar in the two jaws, the inferior are, nevertheless, a 

 little longer and more porous and roughened at the level of their free 



FIG. 290. Double inferior right canine tooth in the ass. 



part. They present for study two faces, two borders, and two extrem- 

 ities. 



Paces. The external or labial face (Fig. 291, A) is convex in both 

 its diameters, that is to say, from above to below and from before to 

 behind. Its free portion shows very fine striae, which eventually dis- 

 appear under the effects of friction. 



The internal or lingual face (Fig. 291, B) is less convex than the 

 preceding. It presents, on the crown, two well-marked grooves, the 

 one anterior, the other posterior, which follow the corresponding borders 

 of the tooth. Between the two is found a triangular eminence whose 

 base is confounded with the remainder of the same face. 



Borders. The anterior border is convex, the posterior concave ; 

 both augment in thickness from the free extremity towards the incased 

 extremity. 



Extremities. The free extremity or crown of the virgin canine 

 tooth (Fig. 292) terminates in a blunt point, flattened transversely, 

 while the embedded extremity, much more voluminous, is occupied by 

 a round opening, which leads into a cavity in the interior of the tooth, 

 terminating in a cul-de-sac. This cavity, of a conical form, contains 

 the pulp. At first spacious, it is gradually obliterated, until it is con- 

 stituted only by a shorjt and narrow canal. The tusk elongates from 

 its root, which becomes pointed, while the opposite end becomes rounded 

 and blunt from the effects of wear. 



But as the canines are not placed in definite relation to each other 



