434 A MANUAL OF DENTAL ANATOMY. 



rent. The canals which everywhere permeate the dentine 

 are not empty, a fact which might be inferred from the 

 difference in translucency and general aspect of dry and 

 fresh dentine, whether seen in mass or in thin section ; 

 neither are they, as was at one time supposed, tenanted 

 merely by fluid. 



Deutinal Fibrils. Each canal is occupied by a soft 

 fibril, which is continuous with an odontoblast cell upon the 



FIG. 28 J . 



surface of the pulp ; the existence of these soft fibrils was 

 first demonstrated by my father, who thus, to use the words 

 of Waldeyer, " opened the way to a correct interpretation 

 of the nature of the dentine." 



Henle, in his "Allgemeine Anatomie," (1841), a transla- 

 tion of a portion of which is to be found in the " Archives 

 of Dentistry," (1865), figured and described projections from 

 the edges of fragments of dentine in continuity with the 

 dentinal tubes. These he distinctly describes as calcified and 

 rigid, adding that by the use of acids they may be made 

 flexible ; he speaks of the tube as empty, save when blocked 

 by granular calcareous matter, and alludes to fluids entering 

 it by capillarity ; and lastly, he says nothing whatever of 

 the connections of the pulp with the tubes. 



Miiller, (as translated in Nasmyth on the "Structure of 



( J ) A fragment of dentine (a), through which run the softer fibrils (c), 

 which are seen to be continuous with the odontoblast cells (6). (After 

 Dr. Lionel Beale.) 



