30 



MOUNTED INSTRUCTION 



when the animal is eight years old, although in very hard teeth it is 

 often not apparent until about eleven years. Depending upon the 

 hardness of the dentine and the character of the food, the teeth wear 

 away at the rate of about one-twelfth of an inch per year. As an incisor 

 is not of uniform shape or size from its crown to its roots, it is at once 

 apparent that wear will continually change the form of its table surface. 

 By their growth, changes of form and wearing, the teeth of the horse 

 furnish a very reliable guide to determine the animal's age. In the 

 adult animal they number from thirty-six in the female to forty in the 

 male, and are classed according to their location, form and functions, 

 as incisors, canines, and molars. The incisors, or cutters, occupy the 

 front part of the mouth. They are twelve in number, six in the lower, 

 and six in the upper jaw. In each jaw there are two central, two 

 lateral, and two corner incisors. The canines, or tushes, occupy the 

 front part of the interdental space. The tushes are usually absent in the 

 mare, or if present, are very small. They are four in number, two in 

 each jaw. The molars, or grinders, occupy the back part of the mouth. 

 They are twenty-four in number, six in each side of the jaw. Naming 

 from front to rear they are designated first, second, third, etc. Quite 

 frequently supplementary molars, called "wolf teeth," are present. If 

 so, they appear directly in front of the first molar, in the upper jaw. 

 To obtain the best view of the mouth, grasp the upper lip firmly with 

 the right hand, and place the left in the interdental space from the right 

 side, using the thumb to depress the lower lip, and the back of the 

 hand to press the tongue upward and backward. In this way the right 

 hand serves as a twitch to hold the horse, while the left one uncovers 

 the lower incisors. 



DENTITION OF THE HORSE 



Ages of horses by the teeth are determined by shedding and appear- 

 ance of the teeth up to four years, a6cording to table. Cups wear out of 

 center pair of incisors of lower jaw at about six years; middle pair of 



