202 AGE OF ANIMALS. 



their point. In the tenth year the kernel has worn out of 

 the teeth next to the middle fronts of the upper jaw, and 

 in the eleventh year the kernel has entirely disappeared from 

 the corner teeth of the same jaw. At twel ve years the crowns 

 of all the front teeth in the lower jaw have become triangular, 

 and the bridle teeth are much worn down. As the horse 

 advances in age the gums shrink away from the teeth, which 

 appear long and narrow, and the kernels become changed 

 into darkish points. Gray hairs increase in the forehead 

 and the chin becomes angular. 



A modification of the foregoing, much more scientific or 

 systematic, and probably quite as reliable, is the classifica- 

 tion of Pessina, a distinguished veterinary surgeon of Ger- 

 many. 



Its principles may be distinctly understood by reference 

 to the accompaning cuts, A, B, C, and D. 



A, represents the corner tooth of a young horse ; the oth- 



FIG. A. 



er nippers' vary very little from this one in their construc- 

 tion and form.' 



The top of the tooth is long from side to side, and the ex- 

 treme lower end is long from front to rear. The manner in 



