48 A MANUAL OF DENTAL ANATOMY. 



which takes the stain deeply, and is probably analogous to 

 the cement substance of epithelial formations. As seen in 

 sections, it gives off exceeding fine thorns, which apparently 

 pierce the prisms at right angles to their length, so that it 

 forms a close network very intimately mixed up with the 

 calcined portion of the enamel. 



It is not of uniform thickness, but is beaded, and Bodecker 

 attributes to it a role of far greater importance than that of 

 a mere cementing substance, for he regards it as being an 

 active, protoplasmic network, which renders the enamel 

 much more " alive " than it has hitherto been considered to 

 be. He believes it to become continuous with the soft 

 contents of the dentinal tubes through the medium of large 

 masses of protoplasmic matter found at the margins of the 

 enamel and dentine. 



But although there are various reasons for suspecting that 

 enamel is not completely out of the pale of nutrition from 

 the moment that a tooth is cut, yet further observations are 

 needed before the activity and importance of the cement 

 substance demonstrated by Bodecker can be held to be fully 

 established. Klein remarks that "the enamel cells, like all 

 epithelial cells, being separated from one another by a homo- 

 geneous interstitial substance, it is clear that the remains of 

 this substance must occur also between the enamel prisms ; 

 in the enamel of a developing tooth the interstitial substance 

 is larger in amount than in the fully formed organ. It is 

 improbable that nucleated protoplasmic masses are con- 

 tained in the interstitial substance of the enamel of a fully- 

 formed tooth, as is maintained quite recently by Bodecker." 



The study of the development of marsupial enamel, to be 

 alluded to at a future page, by showing that the enamel is 

 penetrated by soft tissue differently placed, also tends to 

 throw doubt upon Bodecker' s interpretation. W. J. Barkas 

 (Monthly Review of Dental Surgery, 1874) has also perhaps 

 had under observation this cementing substance ; he also 



