64 DIGESTION AND FOOD. 



There ,are occasionally very singular conditions of the teeth 

 of horses, and one of the most common is the persistence 

 in the jaw of some of the temporary incisors. This arises 

 from the latter not having been pressed upon by the advan- 

 cing permanent teeth, and they then lose the colour and form of 

 colt's teeth. I have known a horse with twelve incisors in 

 the lower jaw, though most frequently the peculiarity only 

 amounts to the presence of one or two extra teeth. Occa- 

 sionally a tooth may be wanting, either from having been 

 removed or never having been developed. Even in these ex- 

 ceptional cases, the appearances of the mouth are fair guides 

 in ascertaining the age of horses. 



