STRUCTURE OF THE HORSE. 



115 



and is up and in wear at two years. With variation of wear, the 

 incisors remain the same during the second year. At two years, 

 the colt has twelve temporary incisors, twelve temporary molars, 

 and eight permanent molars. x\bout the middle of the third 

 year the nippers, or central temporary incisors, fall out, and are 

 replaced by permanent incisors, which are up and in wear at 

 three years of age. About the time of shedding the temporary 

 incisors, two more permanent molars make their appearance, the 



Fig. 13 — Upper Incisor Teeth of a Five 

 Year Old Horse. 



1, 1. Central incisors with cup unoblit- 

 erated. 2, 2. Lateral incisors with cups 

 deeper and larger. 3,3. Corner incisors, 

 still larger cups, with their edges very 

 slightly xt^orn. 4, 4. Canine teeth well 

 developed. 



Fig. li — Lower Incisor Teeth of a Five 

 Year Old Horse. 



1, 1. Central incisors. 



Z, 2. Lateral incisors. 



3, 3. Corner incisors. 



i,i. Canine teeth. The cups are some- 

 what obliterated in the teeth of the 

 lower jaw at five as shown. 



first and second in the jaw. Hence at three years the colt has 

 eight temporary incisors, four permanent incisors, four tempo- 

 rary molars, and sixteen permanent molars. 



At the age of three years and six months the temporary late- 

 ral incisors are replaced by permanent ones. They are up and 

 in wear when the colt reaches the age of four years. The fifth 

 permanent molar now makes its appearance, being the third in 

 the jaw. A little later the sixth makes its appearance; it is also 

 the sixth in the jaw. All the molars are up and in wear at four 



