344 



TERMINATION OF SENSORY NERVES. 



perineurium successively become continuous with, or rather expand into the tunics 

 of the corpuscle. Since, however, in most Pacinian corpuscles there are many 

 more tunics in the corpuscle than layers of the perineural sheath which invests 



Fig. 404. DIAGRAMMATIC REPRESENTATION 



OF TWO TUNICS OF A PACINIAN COR- 

 PUSCLE IN TRANSVERSE SECTION. 



, rt, epithelioid layers ; 6, &, connective 

 tissue layer, more condensed near the sur- 

 face ; c, open network of fine elastic fibres 

 in the substance of the lamella. 



the entering nerve, it is only a few 

 of the tunics which are thus con- 

 tinuous ; and it will be generally 



found that it is the outer ones which are so. A certain number of the inner 

 tunics are superadded therefore, and when traced towards the nerve-fibres they may 

 be seen to end with rounded margins bounding a canal in which the nerve-fibre 



Fig. 405. PACINIAN CORPUSCLE FROM THE MESENTERY OF THE CAT; STAINED WITH NITRATE OF SILVER. 



MAGNIFIED. 



The epithelioid cells of the outermost tunic are shown, and their continuity, at the peduncle, with 

 those of the corresponding layer of the perineurium (from a drawing by G. C. Henderson). 



Fig. 406. PART OF PACINIAN BODY SHOWING THE NERVE-FIBRE ENTERING THE CORE. FROM AN 



OSMIC ACID PREPARATION. (E. A. S.) 



ms, entering nerve-fibre, the medullary sheath of which is stained darkly, and ends abruptly at the 

 core ; p, s, prolongation of primitive sheath, passing towards the outer part of the core ; c f, axis- 

 cylinder passing through the core as the central fibre ; e, some of the inner tunics of the corpuscle, 

 enlarged where they abut against the canal through which the nerve-fibre passes : n, nuclei of the 

 tunics ; n', nuclei of the endoneurium, continued by others in the outer part of the core. 



runs. The latter is accompanied by a little endoneural connective tissue which 

 generally contains a number of granular cells (fig. 406). 



