106 A MANUAL OF DENTAL ANATOMY. 



during the period of their greatest functional activity the 

 end directed towards the dentine is squarish, though tapering 

 to a slight extent into the dentinal process ; while in old 

 age they become comparatively inconspicuous, and assume 

 a rounded or ovoid shape. The general matrix of the pulp, 

 as has been before noted, is of firm, gelatinous consistency : 

 it is a little more dense upon the surface, whence has 

 perhaps arisen the erroneous idea that the pulp is bounded 

 by a definite membrane. 



The vessels of the pulp are very numerous ; three or 

 more arteries enter at the apical foramen, and breaking up 

 into branches which are at first parallel with the long axis 

 of the pulp, finally form a capillary plexus immediately 

 beneath the cells of the membrana eboris. 



No lymphatics are known to occur in the tooth pulp. 



The nerves enter usually by one largish trunk and three 

 or four minute ones : after pursuing a parallel course, and 

 giving off some branches which anastomose but little, in the 

 expanded portion of the pulp they form a rich plexus beneath 

 the membrana eboris, as has been described by Raschkow 

 and many subsequent writers. 



But here our exact knowledge ends, for the nature of the 

 terminations of the nerve fibres in the pulp is not with 

 certainty known : the primitive fibrils, which are extra- 

 ordinarily abundant near to the surface of the pulp, often 

 form meshes, but this does not appear to be their real 

 termination. 



Boll, as has been mentioned at a previous page, investi- 

 gated this point, and found that if a pulp be treated for an 

 hour with very dilute chromic acid solution, an immense 

 number of fine non-medullated nerve fibres, which he suc- 

 ceeded in tracing into continuity with the larger medullated 

 fibres, may be discerned near to the surface of the pulp. 

 The ultimate destination of these nerve fibres is un- 

 certain ; but he has seen them passing through the mem- 



