78 THEORY OF FEEDING. 



Each tooth is lodged in a socket in it's jawbone, and is 

 developed from its dental pulp, which is provided with 

 blood-vessels, nerves, and secreting cells. Owing to the 

 continued secretion of dentine, the teeth are forced slowly 

 out of their sockets, which movement more or less makes 

 up for the wear entailed on the teeth by mastication. 

 Our own teeth, on the contrary, remain stationary in their 

 sockets after they have attained their full size. The greater 

 amount of wear undergone by the back teeth of a horse is 

 compensated for by the increasing obliquity of the incisors 



Fig. 3. Transverse Section of Skull of Horse, showing position of 

 back teeth when the animal is chewing on the left side of his mouth. 



with age. As the teeth wear down in time, the layers of 

 enamel of both the front and back teeth gradually become 

 thinner and weaker, until at last they disappear altogether or 

 fail to fulfil their purpose as cutting projections on the tables 



