68 A MANUAL OF DENTAL ANATOMY. 



dentine from a half-formed human incisor. The matrix is 

 slightly stained with the carmine, indicating that it has not 

 yet become fully impregnated with salts, and in the centres 

 of the clear areas dark spots deeply stained with carmine 

 are to be seen, the latter being transverse sections of the 

 dentinal fibrils in situ. I have observed precisely similar 

 appearances in the thin young dentine of calves' and pigs' 

 teeth ; Kblliker also mentions that the dentinal fibril may 

 be recognised in situ in transverse sections of fresh dentine. 



FIG. 31 (*). 



Bodecker finds that the dentinal fibrils stain darkly with 

 chloride of gold ; when viewed in transverse sections under 

 a magnifying power of 2,000 diameters they do not appear 

 round but somewhat angular, and give off tiny lateral 

 offshoots which seem to penetrate the dentine. In the 

 matrix itself there is an appearance of a faint network when 

 it has been stained with gold, and from this Bodecker infers 

 that the dentine is penetrated everywhere by a network 

 of living plasm, derived from, though far finer than, the 

 dentinal fibrils. 



Probably the angularity of the fibril, which, as figured by 

 him, is much smaller than the canal, is due to its having 

 shrunk under the action of chromic acid or some such 

 reagent. 



( l ) Transverse section of dentine : in four of the dentinal tubes, the 

 dentinal fibrils deeply stained with carmine, in the preparation from which 

 this figure was drawn, are seen. The fibrils are somewhat shrunken, 

 owing to the action of the glycerine in which the section is mounted. 



