THE DEVELOPMENT OF THE TEETH. 151 



the borderland of calcification, between the completed fully 

 calcified tissue and the formative matrix as yet unimpreg- 

 nated with lime, there very constantly exists a stratum of 

 tissue which in its physical and chemical properties very 

 much resembles " calcoglobulin." 



It should also be noted that globular, spherical forms are 

 very constantly to be seen at the edges of the thin cap of 

 forming dentine, and may be also traced in and around the 

 interglobular spaces (see Fig. 34) ; moreover, isolated 

 spherules of lime salt have been described by Messrs. Kobin 

 and Magitot as occurring abundantly in the young pulps of 

 human teeth, as well as those in the herbivora, where their 

 presence was noted by Henle. 



CALCIFICATION OF THE ENAMEL. 



Although the calcification of the dentine commences 

 before that of the enamel, it will be convenient to describe 

 that of the enamel first, as being a somewhat simpler and 

 more easily intelligible process. 



As has already been mentioned, I am distinctly of opinion 

 that the enamel is formed by the actual conversion of the 

 cells of the enamel organ into enamel, but as this view is 

 not held by all who have written upon the subject, I will 

 first mention the alternative theory, namely, that the enamel 

 is in some sense secreted or shed out by these cells. In 

 support of this latter theory the names of no less authorities 

 than Professor Huxley, Kolliker, Wenzel, and Magitot, may 

 be adduced, but the grounds on which their decisions are 

 based are appearances susceptible of a different interpreta- 

 tion. Kolliker considers that the cells do not undergo any 

 direct conversion, but that the enamel is shed out from the 

 ends of the enamel cells, the enamel fibres therefore corre- 



