NATURAL HISTORY OF THE HORSE. ^ 



raised and sharp, is brought to a level with the inner 

 edge, and so the mouth continues until some time between the 

 sixth and ninth month, when another nipper begins to appear 

 on each side of the first two, making six above and below, and 

 completing the colt's mouth ; after which the only observable 

 difference, until between the second and third year, is in the 

 ^vear and tear of these teeth. 



These teeth are covered with a polished and exceedingly 

 bard enamel ; indeed, it is so hard that it almost bids defiance 

 to the action of a file. It spreads over that portion of the 

 tooth which appears above the gum, and not only so, but as 

 they are to be so much employed in nipping np the grass and 

 gathering the animal's food — and in such employment even 

 this hard substance must be gradually w^orn away — a portion 

 of it, as it passes over the upper surface of the teeth, is bent 

 Inward, and sunk into the body of the teeth, and forms a little 

 pit in them. The inside and bottom of this pit being black- 

 ened by the food, constitute the mark in them, by the gradual 

 disappearance of which, in consequence of the wearing down 

 of the teeth, we are enabled for several years to judge of the 

 age of the animal. 



The colt's nipping teeth are rounded in front, somewhat 

 hollow toward the mouth, and presenting a cutting surface, 

 with the outer edge rising in a slanting direction above the 

 inner edge. This, however, soon begins to wear down, until 

 both surfaces are level, and the mark, which was originally 

 long and narrow, becomes shorter, wider, and fainter. At 

 six months, the four nippers are beginning to wear to a level. 



The annexed cut will convey some idea of the appearance 

 of the teeth at twelve months. The four middle teeth are 



