THB TEETH. 257 



colt which feeds on its mother's milk and on young and more tender food 

 than does the adult horse. The circular form of the position of the teeth 

 is less in the adult horse than in the colt, and gradually grows less as the 

 horse grows old, until in old age the incisors are arranged in nearly a 

 straight line. 



Temporary Teeth. The foal is born with his teeth in a rudimentary 

 state in the gums. During the first ten months the different temporary 

 incisors appear. 



Yearling. The yearling has complete in all six incisors in each jaw. 

 The teeth show but little wear and the corner teeth are mere shells, hav- 

 ing inner walls, and all the teeth are close together. 



Two-Years-Old. At this age the inside walls of the corner teeth 

 have grown up level with the outer wall. The center teeth show con- 

 siderable wear and appear smaller than in the yearling on account of the 

 increase in the size of the jaw. They have become somewhat wider 

 apart at their necks. 



Three-Years-Old. The horse sheds the two center teeth a few 

 months before he is three years old and they are replaced by permanent 

 ones. Thus the jaw at three years of age contains two centre permanent 

 teeth and two temporary teeth in each side. 



F'otir- Years-Old. A few months before four years old the horse 

 sheds the two next milk teeth, which are replaced by permanent ones. 

 Thus at four years of age the jaw contains four permanent teeth and one 

 milk tooth on each side. 



Five-Years-Old. The remaining milk teeth are shed a short time 

 before the horse becomes five years of age and are replaced by permanent 

 ones. The jaw is now complete, but the corner teeth are shells, having 

 no inner walls. The absence of this wall distinguishes the five from the 

 six-year-old mouth. 



Six- Years-Old. The inner wall of the corner permanent teeth have 

 by this time grown up level with the outer wall. The mouth now being 

 complete in incisors, and no further structural changes take place in 

 them. As a general rule, the upper temporary teeth fall out sooner than 

 the lower ones. 



Up to six years of age, since there are structural changes, there can 

 be but little doubt as to the age of the horse. High feeding encourages 

 growth of the teeth as well as of other parts of the body, therefore 

 >-.horoughbreds are somewhat more forward in their mouths than half- 

 breed animals, 



