THE AGE. 69 



After this period, and until the horse teeth 

 appear, the "mark," guides us in determining 

 the animal's age. 



At twelve months, the cavity is all but obli- 

 terated from the two central nippers ; and in 

 those on each side of them, the " mark" is less 

 extended from side to side than it was at first. 



At eighteen months, the " mark" is gone 

 from the four central teeth, and the two that 

 first appeared are nearly triangular on their 

 wearing surface, taking the shape of the root as 

 they are worn down to it. 



At two years, the "mark" is gone fix)m all 

 the six, and the two central teeth appear con- 

 siderably smaller than the side ones. 



At two and a half years, the two central milk 

 teeth become loose, drop out, and the first two 

 permanent nippers appear in their places, and 

 are soon on a level with the remaining four milk 

 teeth. The permanent nippers are larger and 

 darker coloured than the temporary ones, and 

 their external surface has a well-marked furrow, 

 which is not observed in the colt teeth. 



Soon after this period, if the colt has been 

 well fed, and is tolerably well furnished, it be- 

 €3omes an object with the breeder to pass him 



