76 AGE OF THE DOMESTIC ANIMALS. 



the corner teeth have fallen out, and we find the inferior borders 

 of the permanent corner teeth appearing first, more frequently 

 in the upper jaw. The pinchers and intermediate teeth are 

 well worn. At this period we frequently find anomalies in the 

 eruption of the teeth. It is not rare to see the intermediate and 

 corner teeth appear at the same time ; so that an animal which 

 is only four or four and a half years of age may have the teeth 

 which ordinarily indicate five years. (Figs. 77, 78, 79.) 



Rising Five Years. — The four temporary corner teetli have 

 fallen out and are replaced by the adult teeth. These last have 

 not yet reached the level of the intermediate teeth and are not 

 yet worn. The pinchers are leveled; their central enamel, 

 elongated from side to side, is found farther and farther away 

 from the anterior border of the dental table. The tables of the 

 intermediate teeth are distinctly formed. (Figs. 80, 81, 82.) 



Five Years. — The mouth is complete ; the incisive arch is 

 semicircular and regular in shape ; all of the permanent teeth 

 have reached the same level. The anterior borders of the corner 

 teeth are completely worn. The posterior are not yet w^orn. 

 (Figs. 83, 84, 85.) 



Five Years Off. — The above characteristics are more distinct. 

 The age has been more marked by the continual friction and 

 amount of work to which the corner teeth have been subjected. 

 In the superior incisive arch, the posterior borders of the corner 

 teeth rarely commence to be worn. The profile of the incisives 

 shows a regular one-half circle, convex from above to below. 



During this period, besides the causes already referred to 

 which produce hasty or tardy eruption of the permanent teeth, 

 other influences may act. Traeger, veterinarian at Doehlen, 

 noticed that gestation in the young mare delayed the eruption 

 of the permanent teeth ; he also observed that continuous preg- 

 nancies diminished the wearing of the teeth. Daring this pe- 

 riod the tusks may make their appearance, or they may be 

 delayed until after all of the incisors are in place. In cases of 

 doubt, a further examination should be made as to the con- 



