THE ANATOMY OF THE HOUSE 



31 



average weight of only 



twenty-three ounces. This 



is an interesting contrast 



with the average weight of 



the brain of a white man 



which is about forty-nine 



ounces. 

 The age of the horse is 



usually estimated by an ex- 

 amination of the teeth. To 



inspect these most easily, 



grasp the upper jaw with 



one hand, the lower with 



the other, the thumbs being 



inserted just back of the 



fnont or incisor teeth. 



^Pressure from the lower 



limid causes the horse to 



drop the under jaw, so that 



the teeth may be quite 



easily examined. It re- 

 quires some experience in recognizing the age, which -may 



be determined with reasonable accuracy in most cases, up 



to eight years. After that there is some uncertainty. The 



appearance of the teeth, and their age classification, is as 



follows : 



The colt teeth. 

 Seven or eight days 

 after birth two incisor 

 teeth appear at tho 

 front and middle of 

 both upper and lower 

 jaws. In the course 

 of five or six weeks, 

 two more teeth ap- 

 pear in each jaw, one 

 tooth coming on either 



Pig. 10. Grasp the uppper jaw 

 with one hand and the lower with 

 the other. 



Fig. 11. The colt teeth. "They are the 

 milk teeth." Figs. 11-18 reproduced from 

 "Beurtheilungslehre des Pferdes," 1859. 



