VE TERINAR T DENTAL S URGER T. 55 



quarter to two and one-half inches in length when 

 they are fully developed. They shorten by being 

 worn away on their table surfaces, and are much 

 wider from side to side in a young animal, while in 

 very old horses they are widest from before back. 

 The upper teeth are the larger and usually have the 

 outer edges of the corner incisors projecting, so that 

 they do not wear evenly, leaving a point of more or 

 less length, which gradually increases with age until 

 the horse is from fifteen to sixteen years old. After 

 this, owing to the gradual change in the position of 

 the incisor teeth the outer edges of the corner teeth 

 slowly come into wear again, and the size of the 

 projection decreases until, in very old horses, it 

 occasionally entirely disappears. The projection is 

 very often removed by artificial means without bad 

 results. 



The molar teeth differ very materially with re- 

 gard to the number of their roots. The first and 

 sixth molars of both jaws each have three roots ; the 

 second, third, fourth and fifth upper molars have 

 each four roots, while the corresponding lower 

 molars have only two roots. They also differ in 

 size; the first is the largest and shortest, the third 

 the longest and the fifth has the smallest grinding 

 surface. 



In extracting teeth it is of importance that the 

 operator should know the direction of each individ- 



