HOW TO TELL THE AGE. 



571 



FIG. 339. 



The shape of the incisor 

 varies considerably when exam- 

 ined in the direction of its 

 length. At its free extremity 

 it is flattened before and be- 

 hind ; further down it becomes 

 oval, then round, then triangu- 

 lar, and at last flattened at the 

 sides, so that if the length of 

 an incisor be divided into a 

 series of cross-sections, a dia- 

 gram will be obtained, showing 

 the change of form with ad- 

 vanced age. 



This will be indicated more 

 particularly by referring to 

 other cuts. 



FIG. 340. Canines, or Tushes 

 (the mare has them only 

 in a rudimentary 

 form) ; A, exter- 

 nal face; B, 

 internal 

 face. 



FIG. 341. Temporary, or 

 Milk Teeth. 



