NATURAL HISTORY OF THE HORSE; 85 



OX and sheep, the horns also present legible indications of the 

 progress of time. 



Reference to the teeth to ascertain the nge of the horse is 

 not by any means of recent origin. Xenophon, in his work on 

 horsemanship, from which we have already quoted, alludes to 

 it as an established custom used in the selection of cavalry for 

 the Grecian armies ; he properly advised the rejection of such 

 horses as have lost the dental mark. The same facts are sub- 

 sequently noticed by Yarro, Columella, Yegetius, and other 

 Roman writers. 



The horse, when full-mouthed, possesses forty teeth — twenty 

 in each jaw. They are named from their use, position, and 

 character. Those in the front of the mouth, whose office it is 

 to gather food when grazing, are termed incisors, or, more pro- 

 perly, nippei^s. They are twelve in number; six above, and 

 six below. ^They do not overlap each other, as is the case in 

 man, but meet in a broad tabular surface. From these teeth 

 the age of the animal is principally decfuced. For the sake of 

 description, they are usually ranged in pairs, as they appear; 

 and the first pair is called the central, the second the dimders, 

 and the third the corner nijypers. The tushes, or canines, 

 come next ; one above, and one below on each side. They are 

 of a pointed form, and are convex on the outer sides, and 

 slightly concave on the inner surface. They scarcely ever ap- 

 pear above the gums in mares, although their rudiments may 

 be discovered on dissection, imbedded in the maxillary bones. 

 T.hey are consequently regarded as sexual distinctions. It is 

 difficult to assign their use ; their position precludes the possi- 

 bility of their being used as weapons of offense or defense. 

 They may be viewed as a link of uniformity so commonly 



