Horses and Horsemastership. 



circular aspect which the mouth hitherto presented is 

 beiug lost through the teeth becoming oblique instead 

 of vertical. 



At nine only the corner teeth retain the distinctly 

 oval shape of the biting surface ; but the process of 

 change goes on until eleven years is reached, when they, 

 too, have become quite circular. As the horse gro\\^ 

 older the circular shape of the teeth gradually changes 

 to a triangular one, the two centre incisors first becom- 

 ing pronouncedly so, then the teeth on either side of 

 them, and lastly (as they were to change from ov£ to 

 circular) the corner teeth. Each succeeding year sees 

 the teeth becoming more oblique, until in extreme old 

 age those in the lower jaw are almost horizontal. 



I have not hitherto mentioned the tusks which appear 

 in the interdental space of every horse's mouth, mid- 

 way between the incisors and the grinders, at about four 

 years old. and reach full development at five and a half. 

 They very occasionally occur in mares, and their use is 

 not apparent. The tusk is a fang-shaped tooth, and 

 there is this peculiarity about it : it becomes blunter 

 and rounder everv year from the time the horse reaches 

 the age of seven, so that in old animals it will be worn 

 down to a level with the gums. Tlie appearance of the 

 tusks, therefore, forms valuable corroborative evidence 

 in estimating the age of a horse. 



