654 THE EXTERIOR OF THE HORSE. 



Three Years Past. The colt has passed his third year by two, 

 three, or four months. The four permanent pincers show wear on 

 their two borders (anterior and posterior), which are on the same level, 

 but the external dental cavity is not yet circumscribed by the circle of 

 central enamel. The milk intermediates are much worn and pushed out, 

 so as to show their bases, and are more or less broken ; one of them is 

 sometimes almost ready to fall out ; the table of the corners is sensibly 

 enlarged and prolonged towards its external border. (Plate XIII.) 



Rising Four Years. Eruption of the adult intermediates and 

 progressive falling out of the milk intermediates. The latter are at 

 times replaced in the two jaws. The newly-erupted teeth are alto- 

 gether virgin and have not attained the level of the corners ; they 

 show no trace of wear. The central enamel, in the pincers, circum- 

 scribes the external dental cavity, flattened from before to behind and 

 already greatly diminished. The milk corners appear much pushed 

 out from the gums and bare at their bases. (Plate XIV.) 



Four Years. Each jaw shows four permanent teeth whose 

 tables have all reached the same level. The intermediates are worn 

 upon both of their borders (anterior and posterior), but the central 

 enamel is not yet completely separated from the peripheral enamel. 

 Often the inferior pincers are levelled, especially in thoroughbred 

 horses. Finally, the corners of the first dentition are constricted at 

 their bases, pushed out, and much levelled. (Plate XV.) 



Four Years Past. Loosening and successive shedding of the 

 deciduous corners, which look like stumps barely able to retain their 

 places. Sometimes one of the superior falls out, and leaves the perma- 

 nent incisor in its place, ready to penetrate through the gums ; at other 

 times the superior jaw already presents, on one side, the free part of 

 the corner of the second dentition. Pronounced wear of the pincers 

 and the intermediates, anomalies in the eruption, also frequently takes 

 place at this period. It is not rare, in fact, to see the eruption of 

 the intermediates and the corners occurring at the same time. The 

 animal is then only four and one-half years old, sometimes only four, 

 although the teeth may actually mark five. 1 (Plate XVI.) 



Rising Five Years. The four milk corners have fallen out and 

 are replaced by those of the adult teeth. The latter, not having reached 

 the same level as the intermediates, do not show the least trace of wear. 

 The pincers show considerable wear ; their central enamel, elongated 

 transversely, is separated from the anterior border of the dental table. 



1 Yvon, v6terinaire a Bayeux, note communique. 



