268 MICROSCOPIC ANATOMY OF THE TEETH 



preparations of the author's suggest that this zone is also 

 penetrated by delicate connective-tissue fibres from the 

 pulp (15 a). The opinions of such an authority as Professor 

 von Ebner, who has studied this subject for many years, must 

 always be received with the greatest respect. 



Klein (12 a) held that the network of reticular tissue in 

 the substance of the odontoblasts is the reticular basis of 

 the dentine matrix, which would be thus an intracellular 

 substance. 



The author in a paper published in 1892 (15 a) showed that 

 connective-tissue fibres from the pulp pass into the forming 

 dentine, and considered that the fibres seen in its substance 

 are the incorporated connective -tissue fibres of the pulp 

 which thus form a meshwork or foundation in which calci- 

 fication takes place. The fibres are intercellular and not 

 intracellular as considered by Klein. 



As described in this paper, in preparations cut by the 

 Koch- Weil process and consequently not decalcified, processes 

 were seen springing from the dentine and blending with the 

 connective tissue of the pulp all around the margin of the 

 pulp cavity. These processes have the appearance of 

 connective-tissue bundles partially impregnated with lime 

 salts. 



At the inner margin of the dentine they are seen to 

 spring from its substance in a direction more or less parallel 

 to the surface, these horizontal bundles of fibres blending 

 together into larger bundles at right angles to the surface 

 of the dentine, much as the spreading roots of a tree coalesce 

 to form its trunk. These bundles, the high refractive index 

 of which suggests their partial calcification, are plainly 

 seen to be continuous with the general connective tissue of 

 the pulp. One is reminded, in looking at these larger pro- 

 cesses, of the similar appearances in the formation of bone 

 in membrane, where spiculae are seen shooting out in advance 

 of the calcified substance (figs. 169 and 170). 



At the apex or coronal portion of the pulp cavity these 

 processes are more slender, form wide open loops, and can be 

 traced for some distance into the pulp. 



In sections cut somewhat obliquely (not in the same plane 

 as the odontoblasts) there is an appearance of small deeply- 



