DENTITION AND DIE] 



131 



the central enamel is almost worn off. At hoelve the corner teeth 

 take on the triangular form, and their central enamel is very con- 

 tracted, and a yellow mark is left. At thirteen the sides of the 

 front teeth thicken, and they l)egin to assume a triangular appear- 

 ance, and the whole incisors of the lower jaw complete the trian- 

 gular form at the age of seventeen. At cUjldeen the front teeth 

 are somewhat flattened from side to side ; the flattening goes on 

 in the mkldle and corner teeth, and is completed at tlie age of 

 iwenty-one, giving them the appearance of a reversed oval. As 

 regards the marks in the upper incisors, they disappear from the 

 front teeth in the course of the ninth year^ from the middle in the 

 tenfa, and from the corner or lateral ones in the eleventh year; 



Fig. 11. 



A PORTION OF THE LOWER JAW OF OT,n BLACK HAWK, 



(Aged twenty-three years and eight months. J 



and as the animal increases in years, the ujjper corner teeth be- 

 come indented or notched. The inclination of the teeth enables 

 us to form some idea of the horse's age. In a young horse, the 

 teeth are upright (see fig. 10) ; after tlie age of eight they gradu- 

 ally become horizontal, (see "Black Hawk's" mouth,) and the 

 iij)per teeth overlap the under ones, and thus wear off their outer 

 edge. 



The Tushes, or Canine Teeth. — Between the ages of four 

 and six the tushes, which, in the male, are four in number, make 

 their appearance. In shape they are conical, with a sharp point, 

 and curved. On the inside there are two furrows, whicii com- 

 mence at the base and meet at the apex, leaving a trianguhir 

 eminence between them. The sliarpness of the apex, the degree 

 of curvature, and the distinctness of the furrows are good crite- 

 rions of youth ; for, as the animal advances in years, the tushes 



