48 ILLUSTRATED STOCK DOCTOR. 



four teeth, (upper and lower), QAWedi foal-teeth . These are all changea 

 by the fifth or sixth year, and those that follow are called horse-teeth. 



The back teeth appear as follows : the three front double pair are seen 

 At birth, and are afterward changed ; the fourth double pair appear from 

 the eio-hth to the ninth month ; (this fourth double pair are the first that 

 remain stationary, and they are found in every year-old colt) ; the fifth 

 double pair, or fifth four, appear in the second or third jq'av ; the sixth, 

 usually in the fourth or early in the fifth year. These three double pairs 

 of back teeth (last named), remain unchanged, as do also the four hook 

 teeth. 



The hook teeth are uncertain as to time of appearance, coining some 

 times at the end of the third year, sometimes in the middle or at the end 

 of the fourth, sometimes in the middle or at the end of the fifth, some- 

 times at the beginning of the sixth. 



Observ^e particularly that the incisors of the foal differ from those of 

 the horse : (1) By their regular, conical formation; (2) by a narrow 

 contraction called the neck, ^dsible almost in the center of the body of 

 each tooth, while nothing of the kind is seen in horse-teeth ; (3) by their 

 smaller size, even when full grown. The milk teeth, (or those teeth 

 which are cast or shed), taken from the jaws of dead foals and compared 

 with horse-teeth similarly obtained, are found to be only about half as 

 long as the latter. The breadth is not to be depended on, since the milk 

 teeth of large foals appear almost as broad as those of small horses. 

 AYhen the nippers become horse-teeth, they form a great contrast to the 

 middle and corner teeth. The size of these last will at once show them 

 to be milk teeth. (4) By the fact that the outer surface of the foal-teeth 

 is smooth and striped with brown, while on horse-teeth the same surface 

 is divided by a dirty A^ellow indentation inclining toward the center, 

 which is sometimes double upon the upper teeth. 



One should stud}'^ the form of the incisors by carefully examining 

 those taken from dead horses of different ages. Each incisor vfHW. be 

 found to consist of a hard, enamelled part, called the grinder, which has 

 protruded above the gum ; of a bony substance, which has been for the 

 most part hidden in the gum ; and of a root, which has occupied the 

 cavity of the jaw-bone. 



These teeth, (of the foal as well as of the horse), are slowly but coii- 

 tinualW worn away by biting and ch3wing, so that the length is constantly 

 decreasing, — sometimes evenly and regularly, — so that in old age the 

 tooth that was once two and a half or three inches Ions; is found to be not 

 exceeding half an inch in length. The breadth generally decreases in 

 about the same proportion ; but with this difference in foal and horse- 

 teeth, that the thickness and breadth of foal-teeth are constantly decreas- 



