ELEPHANT. 651 



commence as usual at the peripheral parts of the lameUiform pro- 

 cesses furthest from the attached base. It may readily be conceived, 

 therefore, that, at the 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 (PI. 146, fig. 4) ; 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 (ib. 5) ; 

 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 con- 

 version, 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 ; these cells or moulds give a sub-transparent bluish 

 tint to the enamel-pulp, which Cuvier distinguishes as the internal 

 layer of the capsule. 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 ossification of the internal layer of 

 the capsule, and that of Blake — that it was a deposition from the 

 opposite surface of the capsule to that which had deposited the 

 enamel, states his own conviction to be — that the cement is produced 

 by the same layer and by the same surface as that which has pro- 

 duced 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 soft internal layer of the capsule with a free 

 surface next the cement. The phenomena could not, in fact, be 

 otherwise explained according to the excretion-theory of dental 

 development. To the obvious objection that the same part is made, 

 by this explanation, to secrete two different products, Cuvier replies. 



