640 THE EXTERIOR OF THE HORSE. 



laws, that the eruption of the incisors of the adult is premature in 

 some and slow in others, we will willingly admit. Nevertheless, this 

 does not appear to us to be exclusively the result of the fact that they 

 belong to such or such a race, possess such or such a temperament, 

 or, finally, that they are abundantly or poorly nourished. We will cite, 

 in this connection, the example which Jules Goubaux, veterinarian 

 at the depot of stallions at Blois, showed us in 1857 : it was a small 

 horse of a common race, which had placed all the incisors of the second 

 dentition in the course of the same year. This early eruption, ex- 

 tremely rare in the horse, occurs less seldom in the bovine and in 

 the ovine species. It must depend upon very diverse causes, which, 

 in our opinion, still remain to be determined. 



B. Eruption of the Canines. 



The eruption of the canine teeth is of little utility in the determi- 

 nation of the age : first, because it is very variable ; secondly, because 

 these are absent in the majority of mares. 



The eruption of the tusks is preceded, accompanied, and followed 

 by the same inflammatory phenomena as those which concern the 

 incisors. According to Girard, there is nothing regular about it. 

 Sometimes these teeth exist at three years ; at other times they only 

 appear at six ; in general they appear at four years. The indications 

 which can be drawn from their state are therefore very uncertain. 



C. Eruption of the Molars. 



In proportion as the animal advances in age the molars of the 

 first dentition, as a result of wear, become shorter and shorter, re- 

 duced somewhat to the state of small, loosened plates, which envelop, 

 as we have seen, the corresponding extremity of those of the second 

 dentition, and are held only very imperfectly in their alveoli. Their 

 asperities, wounding the internal face of the cheek, sometimes cause 

 abnormal movements of the jaws. The animal does not eat in the 

 ordinary manner : this is what attracts the attention and leads to an 

 examination of the interior of the mouth. 



It is good practice, under such circumstances, to extract these teeth 

 so as to favor the eruption of the replacing ones ; an easy operation, 

 and one which veterinarians in breeding districts practise very often. 



The last three molars of each jaw, or the hind-molars, also appear 

 one after the other ; but, situated very deeply in the interior of the 

 mouth, it is difficult to observe well their eruption. 



