PEVELOPMENT OF ELEPHANT'S GRINDERS. 287 



commencement, there is formed a little cap upon each of 

 the processes into which the edges of the pulp-plates are 

 divided. As the centripetal calcification proceeds, the 

 caps are converted into horn-shaped cones. When it has 

 reached the bottom of the notches of the edge of the pulp- 

 plate, all the cones become united together into a single 

 transverse plate; and, the process of conversion, having 

 reached the base of the pulp-plate, these plates coalesce 

 to form a common base to the crown of the tooth, which 

 would then present the same eminences and notches that 

 characterized the gelatinous pulp, if, during the period of 

 conversion, other substances had not been formed upon 

 the surface and in the interspaces of the pulp-plates. 



Coincident, however, with the formation of the dentine, 

 is the deposition of the hardening salts of the enamel in 

 the extremely slender prismatic cells, which are for the 

 most part vertical to the plane of the inner surface of the 

 folds of the capsule to which they are attached. The 

 true inner part of the capsule forms those thick transverse 

 folds or partitions which support the enamel organ, and 

 with it fill the interspaces of the dentinal pulps. With 

 regard to the formation of the cement, Cuvier, after citing 

 the opinion of Tenon — that it was the result of ossifica- 

 tion of the internal layer of the capsule, and that of 

 Blake — that it was a deposition from the opposite surfixce 

 of the capsule to that which had deposited the enamel, 

 states his own conviction to be that the cement is pro- 

 duced by the same layer and by the same surf\\ce as that 

 which has prod need the enamel. The proof alleged is, 

 that so long as any space remains between the cement 

 and the external capsule, that space is found to contain a 

 8oft internal layer of the capsule with a free surface next 

 the cement. The phenomena could not, in fact, be other- 



