100 MICROSCOPIC ANATOMY OF THE TEETH 



Transverse sections of the enamel of Macropus which 

 had been treated by the fuchsin method showed that the 

 interprismatic substance is abundant and is deeply stained, 

 and in some places there is a faint staining of the prisms 

 themselves (fig. 57). The transverse sections of the tubes 

 are much more deeply stained than the interprismatic 

 substance, and are seen to be lying within this interprismatic 

 substance and not within the prisms. In those sections 

 that are directly transverse, the author could find no tubes 



FIG. 54. Passage of dentinal tubes into the enamel in Bettongia. 

 Weil ground section, e. Enamel ; d. dentine. ( x 150. ) 



that could be considered to be within the prisms. Here 

 and there one is seen which at first sight might be 

 thought to be within the prism, but careful focusing 

 shows that this appearance is caused by the spiral course 

 of many of the tubes which are seen through the thickness 

 of the sections. In very thin preparations, which are very 

 difficult to obtain, the author cannot but consider that the 

 tubes are indubitably shown to lie within the stained 

 interprismatic substance. 



C. S. Tomes describes transverse sections of marsupial 

 enamel in which he says that three-fourths of the tubes 

 appear clearly to be in the substance of the prisms, the 



