(36 



THE HORSE IN HEALTH AND DISEASE 



teeth erupt two influences are at work to destroy them — the per- 

 manent teeth are si'aduaUy encroaching on their roots, while the 

 crown is becoming shorter and shorter under the influence of wear, 



1. 1 



Fig. 1(5. — Upper teeth, liard palutc, and adjacent part of soft palale: 1.1, 

 First incisor; I.?, second incisor; Di..?, deciduous third incisor; P./, "wolf tooth" 

 or first premolar; P.-''-.^, premolars; TS/l. 1-3, molars; 1, groove of palate; 12, ridges 

 of palate; 3, soft palate. (Si.sson, Anatomy of Domestic Animals.) 



until at the age of two and on(>-half years there remains only a 

 loosened shell. 



To determine the age of u horse the time of eruption and wear of 

 the teeth are used as guides. In young horses the permanent 



