26 ELEMENTS OF HIPPOLOGY. 



Sometimes the temporary teeth are pulled to make the colt 

 appear older, and occasionally the corner teeth and intermediate, 

 especially in the upper jaw, are shed at nearly the same time — 

 about four. However, this is not the rule. 



Second: The angle at which the teeth of the two 

 jaws meet. 



The younger the horse, the more nearly the angle made by 

 the prolongation of the front faces approaches 180 degrees. This 

 angle becomes more and more acute as the horse grows older. 

 Compare the angle made by the outer faces of the upper and 

 lower teeth in Figures 11 and 12. 



Third: Whether or not they meet accurately. 



If the teeth do not meet accurately, the tables of the teeth 

 do not wear as uniformly as in the normal case and their ap- 

 pearance is not a good index of the horse's age. 



If the upper jaw is longer than the lower one, the upper 

 teeth will, when the mouth closes, project beyond the lower ones . 

 This malformation is termed parrot mouth. The contrary 

 case, much more rare, is termed undershot. The cuts on the 

 opposite page illustrate each case. It is very difficult to ap- 

 proximate the proper age of horses possessing either of these 

 malformations, since the teeth, not meeting, do not wear away 

 according to the general rule. 



The horse whose mouth is shownW Figure 14 has the habit 

 of biting at the woodwork of his stall, the picket-rope — anything 

 within his reach. This habit is known as cribbing, and is the 

 cause of the wearing away of the upper teeth. This animal was 

 known to be between eighteen and twenty when this picture 

 was taken. 



Fourth: The appearance of their outer faces. 



The teeth of a young animal show smoother surfaces (are 

 less stained and chipped on the edges) than the same teeth in 

 older horses. Young teeth are whiter than old ones, and have not 

 such pronounced deposits of tartar on the margins of the gums. 

 Compare Figures 15 and 16. 



