258 THE HORSE. 



component parts of these teeth causes them to wear away with 

 different degrees of rapidity, and thus leaves a rough surface, 

 which materially aids in grinding down the hard grain which 

 forms a large portion of the animal's food. In the upper jaw, the 

 table presented by each molar tooth is much larger than those of 

 the corresponding lower teeth, and therefore it is easy to distinguish 

 the one from the other. 



The temporary or milk incisors differ in shape a good deal 

 from the permanent set. The milk teeth are altogether much 

 smaller, but especially in the neck, which is constricted in them, 

 whilst in the permanent set, which go on growing as they wear out, 

 the diameter is nearly the same throughout. The former are also 

 whiter in color, and have grooves or indentations on their outer 

 surfaces, running towards the gum. Lastly, the mark on the table 

 is much slighter than in the permanent teeth. The temporary 

 molars are not distinguishable from the permanent teeth of that 

 class. 



As A CONSEQUENCE OF THIS ARRANGEMENT OF PARTS, the 



teeth, as they wear down, present a different appearance according 

 to the extent to which their attrition has reached. On this ftict i^ 

 founded a means of arriving at a knowledge of the age of the 

 horse ai'ter he has shed his milk teeth, which as a rule he does in 

 pairs at certain fixed periods. In order, therefore, to be able to 

 estimate the age of the horse from his teeth, it is necessary to 

 ascertain, as nearly as may be, the exact time at which he puts up 

 each pair of his milk or sucking teeth, and afterwards the periods 

 at which they are replaced by the permanent teeth. Finally, it 

 becomes the province of the veterinarian to lay down rules for 

 ascertaining the age from the degree of attrition which the per- 

 manent teeth have undergone. For these several purposes, the 

 horse's mouth must be studied from the earliest period of his life 

 up to old age. 



In horseman's language the incisors are called nippers^ the 

 canine teeth tushes, and the molars grinders. 



By the END OF THE FIRST YEAR the colt has cut his twelve 

 nippers and sixteen grinders, which usually pierce the gums at the 

 following months. Before birth, the eight anterior grinders have 

 generally sh^wn themselves, followed about a weeck after foaling 

 by the two central nippers. At the end of the first month another 

 grinder makes its appearance all round, and in the middle of the 

 second the next nipper shows itself By the end of the second 

 month the central nippers have attained their full size, and the 

 second are about half-grown, requiring another month to overtake 

 their fellows. Between the sixth and ninth months the corner 

 nippers are cut, and towards the end of the first year reach their 

 full size. This first set of nippers consists of teeth considerably 



