ENAMEL, 



53 



precisely similar to that of the processes of the bone-corpuscles to the canalic- 

 uli of bone. The outer portion of the dentine, underlying the cement and 

 the enamel, figure 63, b, c, contains cells like bone-corpuscles. 



Dentine 



Periosteum of 

 alveolus 



Cemen 



Enamel 



Cement 



, Lower jaw bone 



PIG. 62. Premolar Tooth and Surrounding Bone of Cat. 



Enamel. The enamel, which is by far the hardest portion of a 

 tooth, is composed chemically of the same elements that enter into the 

 composition of dentine and bone, but the animal matter amounts only to 



a 



FIG. 63. Section of a Portion of the Dentine and Cement from the Middle of the Root of an 

 Incisor Tooth, a, Dental tubuli ramifying and terminating, some of them in the interglobular 

 spaces b and c, which somewhat resemble bone lacunae; d, inner layer of the cement with numerous 

 closely set canaliculi; e, outer layer of cement; /, lacunae; g, canaliculi. X 350. (Kolliker.) 



about 2 or 3 per cent. It contains a larger proportion of inorganic matter 

 and is harder than any other tissue in the body. 



