162 MICROSCOPIC ANATOMY OF THE TEETH 



spherites become fused together and form a calcified matrix 

 for the enamel prisms. 



That the interprismatic substance is formed by the fusion 

 of these larger bodies and that they can be distinguished in 

 fully formed enamel is shown by the following observation. 

 A thin ground section of a human tooth which was affected 

 by commencing caries, and showed a deep fissure in the 

 enamel, nearly but not quite reaching the dentine, was 

 examined under the microscope. Surrounding the fissure, 



FIG. 94. Enamel of carious adult molar. Ground section (Weil process). 

 c. Large spherites revealed by action of the acid in caries ; p. transverse 

 sections of the prisms showing their granular structure (compare with 

 fig. 91). (x 1,000.) 



the contours of large calcospherites of a radial nature, 

 similar to those seen in the teased preparations of marsupial 

 enamel, are clearly visible, the acids produced in the carious 

 process having dissolved a portion of the lime salts and 

 revealed the actual contours of the calcific deposit. It 

 would, therefore, appear that although many of these larger 

 bodies in the process of calcification break up and become 

 granular, others become fused together and still retain their 

 original form (fig. 94). 



Professor Underwood (28 a) described a similar appearance 



