470 



SPECIAL HISTOLOGY. 



Fig. 159. 



behind the peritoneum, particularly near the pancreas, fre- 

 quently also in the mesentery, close to the intestine ; and also 

 occasionally on other nerves, such as the n. pudendus communis, 

 on the glans penis (Fick) and bulb of the urethra, on the inter- 

 costal nerves, sacral plexus, cuta- 

 neous nerves of the upper- and 

 fore-arm, on the dorsum of the 

 hand and foot, and the cutaneous 

 nerves of the neck. 



The structure of the Pacinian 

 bodies is, upon the whole, simple 

 (fig. 159). Each of them consists 

 ...d of very numerous (20 — 60) con- 

 centric layers of connective tissue, 

 of which layers the external are 

 separated by wider, and the internal 

 — / by narrower interspaces, in which is 

 contained a clear serous moisture, 

 which is collected in larger quan- 

 tity in an elongated central cavity, 

 bounded by the innermost lamella. 

 Each body presents a rounded pe- 

 duncle, formed from the continua- 

 tions of its lamella?, and connected 

 with a nervous twig, and in which 

 a dark nerve-fibre, 0'006 — O^S'" 

 (in the Cat, 0-0044-0-0077'") thick, 

 runs to the Pacinian body. This 

 fibre enters the central cavity from 

 the peduncle, where it becomes 

 * 0-006'" wide and 0-004'" thick, 



pale, non-medullated, almost like an axis- cylinder, and ter- 

 minates in the upper part of the cavity, in a free, slightly 

 granular tubercle, the extremity being frequently bifid or trifid. 

 Further observations, and comparative anatomical details 

 with regard to these bodies, which are also found in great 

 number in many Mammalia, as well as in Birds, in the 



Fig. 159. A Pacinian body in Man, x 350 diam.: a, its peduncle; b, nerve-fibre 

 in it; c, external; d, internal layer of the sheath; e, pale nerve-fibre in the central 

 cavity ; /, divisions and terminations of the same. 



