758 THE EXTERIOR OF THE HORSE. 



oblique teeth that have a tendency to become horizontal ; they are all the more 

 liable to this, as the subjects which present it are in the habit of cribbing most 

 often upon a manger whose free border has its two edges very rounded. 



a. The posterior bevel only exists above (A). 



b. It only exists below (). 



c. It exists in both jaws (C). 



Whatever may be its seat, it makes the teeth of the horse to a certain extent 

 analogous with those of cattle ; they are no longer in apposition, excepting by 

 the more or less small portion of the anterior part of their tables. 



3d. The Abnormal Wear exists at the same time upon the Ante- 

 rior Pace of the Incisors of one Jaw and upon the Posterior Face 

 of those of the other (Fig, 327, D, and Fig. 328, A). The varieties which 

 are met in this category interfere more particularly with the proper determination 

 of the age, for they show themselves, both above and below, by a diminution in 

 extent of the tables, and on opposite sides. It is necessary, therefore, to replace, 

 in imagination, the portion removed by the wear, first in one jaw and then 

 in the other, which doubles its difficulties ; while in the preceding categories 

 the portions to be replaced were of the same nature in each arcade. There are, 

 therefore, and in the same subject, a combination of two forms which we will 

 pass in review. 



Two varieties may be observed : 



a. The Anterior Bevel above and the Posterior below (Fig. 327, 

 Z)). This variety is seen; for example, in horses which crib upon a manger whose 

 free border presents upon its external edge a sort of round iron moulding projecting 

 from the sides, and turned outward and downward. The surface of this mould- 

 ing gives the point of contact to the upper teeth, whilst the lower glide along its 

 edge by a retropulsive movement of the inferior jaw at the moment of the per- 

 formance of the act. There are also circumstances in which cribbing is accom- 

 plished by the previous contact of the superior jaw. It is then only (when it 

 has been once executed) that the animal, incited by a singular mania, rubs his 

 inferior incisors across the edge in question, from one side to the other, and 

 repeats the act several times during a few moments. 



b. The Anterior Bevel below and the Posterior above (Fig. 328, A). 

 It is seen that, in this case, the marking is completely the reverse of the pre- 

 ceding. It is produced by seizing a round body with the jaws, as the border of a 

 window, the extremity of the shafts, for example. This variety, however, is less 

 common, because it necessitates a position of the head more uncomfortable for 

 the animal. The latter, in fact, should approach the vertical direction, in order 

 to allow the superior teeth to cut with their posterior face, an attitude which the 

 subjects do not always find it possible to assume. 



4th. The Abnormal Wear only affects the Dental Tables (Fig. 328, 

 B, C, D). This variety of wear is the most singular, for its only abnormal con- 

 dition consists in a simple shortening of the teeth. But, as all horses which 

 have the incisors too short are riot necessarily cribbers, and as, besides, in all 

 cribbers they are not invariably shorter than is necessary, it follows that the 

 unprejudiced observer cannot well recognize the character of this particular 

 shortening of which we>now speak. In 1842, M. Mignon remarked l that it 



Mignon, Nouveau trait des vices redhibitoires, 1842, p. 361. 



