ANIMAL DENTISTRY. 113 



incisors, with the possible exception of the corners, are long 

 and completely conceal the inferior incisors from an an- 

 terior view when the mouth is closed, the contact edge of 

 the superior incisor arcade overlaps that of the inferior, and 

 finally the tables of the central inferior incisors are becoming 

 circular and even flattened from side to side. (Figs. 78, 79.) 



Twenty to twenty-five years — The mouth presents all 

 the features of the foregoing paragraph with the exception 

 that the enamel island, representing the last vestige of the 

 infundibulum, has entirely disappeared and is replaced by 

 either a light or dark spot — the dental star — -which repre- 

 sents the obliterated pulp cavity. The tables are round and 

 the external enamel around them projects beyond the sur- 

 face of the dentine within, and the crowns of the superior 

 incisors are widely separated with gums and are very nar- 

 row at the gingival end. (Fig. 79.) 



Old age — The mouth of an old horse may present either 

 very long or very short (worn out) incisor teeth. If long, 

 the implantation can be disturbed on manipulation and can 

 almost be extracted with the fingers. If short, the crowns 

 at the tables are separated one from another by the gums, 

 the crowns are round and the tables of the inferior centrals 

 are flattened from side to side. The canines are round and 

 the molars are uneven, easily extracted, and their roots can 

 be felt along the gingival margin. Often a number of molars 

 are absent from self-extraction. 



ROUTINE OF THE EXAMINATION OF A HORSE'S 

 MOUTH TO DETERMINE THE AGE. 



I. The horse is approached on the left side and the lips 

 are opened laterally, the left hand elevating the upper lip as 

 the right depresses the under one, thus exposing the lateral 

 aspect of the incisor arcades. A glance at the inclination 



