THE AGE OF THE HORSE. 79 



year, from the next pair at the age of two years, and 

 from the corner nippers at the age of three years. 

 The milk-teeth are replaced by the permanent teeth 

 in the following order : 



(1) One to two weeks after birth the first two teeth 

 (centre nippers) of the set of milk teeth appear in 

 lower and upper jaw, (Fig. 13-1) which, at the age of 

 two years, become loose and fall out, and in their 

 places appear permanent teeth (No. 4) with deep 

 cavities or marks and sharp edges. 



(2) About six weeks after birth, appear the next 

 pair of milk teeth in both jaws, (No. 2), which fall 

 out with three years old, and permanent teeth grow 

 up in their place, (No. 5). 



(3) About eight months old, the last milk teeth, 

 the corner nippers appear, (No. 3) wliich fall out at 

 the age of four years, and the last permanent teeth 

 make their appearance, (No. 6) so that with five 

 years old, the teeth are all in line and the horse has 

 his permanent set of teeth. 



The teeth grow every year from i to i\ of aninch^ 

 but are worn away at the same ratio by use, so that 

 with — 



Six years old the black cavities or marks have 

 disappeared from the centre nippers. (Fig. 7). 



Seven years old the black cavities or marks have 

 disappeared from the next pair. (Fig. 8). 



