INTRODUCTION. XXIX 



the adjoining inner surface of the capsule, at the sixteenth week ; 

 the surface of adherence of the ' enamel-pulp ' is progressively- 

 extended until it is separated by a mere linear interspace from the 

 base of the ' dentinal pulp.' " Whatever eminences or cavities 

 the one has, the other has the same, but reversed; so that they 

 are moulded exactly to each other. "(1) 



With regard to the development of the dentine, Hunter describes 

 it as an ' ossification,' but without indicating the relation that the 

 pulp bears to the process. " As the ossification advances it gradu- 

 ally surrounds the pulp till the whole is covered by bone, excepting 

 the under surface ; and while the ossification advances, that part 

 of the pulp which is covered by bone is always more vascular than 

 the part which is not yet covered. The adhesion of the pulp to the 

 new-formed tooth or bone is very slight, for it can always be separated 

 from it without any apparent violence, nor are there any vessels 

 going from the one to the other ; the place, however, where it is 

 most strongly attached is round the edge of the bony part, which is 

 the last part formed." " Both in the body and in the fang of a 

 growing tooth, the extreme edge of the ossification is so thin, trans- 

 parent and flexible, tbat it would appear rather to be horny than 

 bony, very much like the mouth or edge of the shell of a snail when 

 it is growing ; and, indeed, it would seem to grow much in the same 

 manner, and the ossified part of a tooth would seem to have much 

 the same connexion with the pulp as a snail has with its shell. "(2) 

 Hunter does not explain the nature of this connexion or the mode 

 of formation of shell ; but he has been generally regarded by Physiolo- 

 gists as having been the author of the theory that the pulp stood to 



(I) Hunter, loc. cit. p. 42. (2) Ibid, p. 39, 40. 



