AGE OF THE HORSE AS SHOWN BY THE TEETH 67 



their outer come in contact with the under 

 surface of the enamel, and cement and sometimes 

 penetrate them. 



The enamel is the hardest portion of the 

 tooth, and chemically is made up of the same 

 elements that go to form dentine and bone. In 

 structure, when examined under the microscope, 

 enamel is found to be composed of fine hexagonal 

 fibres, which are placed on end to the surface of 

 the dentine, and fit into minute cavities on its 

 surface. As has been already stated, the 

 enamel is covered on its outer surface by a thin 

 membrane, which is calcified, and termed the 

 cuticle of the enamel. 



Arrangement of the Teeth. 



The horse possesses forty teeth — viz., twelve 

 incisors, four tushes, and twenty-four molars. 



The incisors are those which are situated in 

 front of the mouth, and are classed in pairs, 

 being usually cut and developed in that way. 

 The middle or centre two are termed the centre 

 incisors, the next to them the lateral, and the 

 two most backward ones the corner incisors. 



