DENTINE 245 



however, all from decalcified teeth except fig. 151, which was 

 taken from a ground section. In ground sections the author 

 has found that the finer branches cannot be brought out in 

 the same preparation in all parts of the dentine as they can 

 in the decalcified sections. Rose states that in transverse 

 sections the branches cannot be seen to communicate with 

 the dentinal fibril, but figs. 149 and 150, where the tubes 

 are seen cut transversely, distinctly show that they can be 

 seen to do so. As the stain penetrates these ramifications 



FIG. 149. Branching of dentinal tubes (silver pyridin). ( x250. 



uninterruptedly there seems very strong evidence that they 

 contain fine subdivisions of the protoplasmic fibril. It is 

 difficult to explain the origin of these fine divisions, but it 

 was supposed by Von Ebner and Kolliker that they arise 

 secondarily by an outgrowth from the dentinal fibril. 

 Waldeyer considered that they were the connecting bridges 

 between the odontoblasts, but Rose says he has never 

 succeeded in demonstrating these connecting bridges, and 

 that ' nowhere in the animal kingdom has such a phenomenon 

 been observed as a process of a connective-tissue cell giving 

 off numerous lateral branches in the form of a feather ' 

 Despite these objections, and whatever may be the 

 explanation of the origin and formation of these delicate 



