146 AGE OF THE DOMESTIC ANIMALS. 



their mangers, chains, wagon-pole, or other foreign bodies, and 

 chip off the edges of the incisors, or they may even wear them 

 to a considerable degree, so as to greatly change their form and 

 tables and interfere more or less with the characters from which 

 we judge the age. In many of these cases, however, the cause 

 is evident, and the unilateral wearing, or the rough, irregular 

 loss of substance, can be replaced by the imagination, and the 

 accurate age determined. 



IRREGULARITIES FROM CRIBBING. 



Cribbing is recognized as of two kinds : 1st, that of the 

 wind-sucker who pursues the habit, nose in air, and consequently 

 produces no abnormal wearing of the teeth ; and 2d, the cribber, 

 who requires some foreign body between its teeth and wears 

 them at the point of prehension. For the former, M. Goubaux 

 proposed, in 1866, the name of" aeropinic." 



According to the manner of cribbing and the character of 

 the object which the horse chooses for support of the teeth, the 

 wearing of the latter may be much varied. The object seized 

 may be the feed-box, the rail of the manger, or a part of the 

 stall, which may be horizontal or may be vertical; it may be 

 the end of a poll or shaft, a chain, hitching-strap, or part of 

 another horse's harness ; in one case of the writer's, the horse 

 would only crib on a small piece of wood when hung loose on 

 a cord. Rare cases crib by seizing their own legs. Sometimes 

 the support is only taken with the lips or the tuft of the chin, 

 and in these there is no wearing of the teeth. 



According to the size of the object, or the position assumed 

 by the horse in cribbing, the contact of the teeth may be only 

 by the anterior borders, only by the posterior borders, or by 

 both ; it may be by one jaw or by both ; it may be by a num- 

 ber of teeth, or only by one or two teeth. In whatever manner 

 the cribbing is done, but little force is used, and the worn sur- 

 face of the teeth is smooth, even, and polished, so that it is 

 readily distinguished from the roughened edges of teeth worn 

 by vicious or nervous biting. When the support of the teetk 



