EXAMINATION OF THE MOUTH FOE AGE. 



89 



5. The arch formed by the incisors in each jaw 

 becomes gradually flatter and flatter. At first, when a 

 horse has a " full mouth," the tables of the incisors are 

 so broad from side to side, that the resulting arch be- 

 comes as round as practicable, in order to afford room 



Fig. 19. — An old mouth, sliowiiig the deposition of cement round tlie 

 stumps of the teeth. 



for the teeth, which, then, more or less radiate outwards 

 (see Fig. 18). As the teeth wear down (see Fig. 19), 

 they obtain more and more room, on account of their 

 becoming narrower from side to side ; and the jaw, con- 

 sequently, *' falls in." 



6. Owing to the irritation set up, by the movement of 



