. Quain's elements of anatomy . corpuscle froh the Fig. n MESENTERY OF THE CAT ; STAINED WITHNITRATE OP SILVER. MAGNIFIED. The epithelioid cells of the outermosttunic are shown, and their continuity, atthe peduncle, with those of the correspond-ing layer of the perineurium (from a drawingby Gr. C. Henderson). by Pacini, the layers of the peri-neurium successively become con-tinuous with, or rather expand intothe tunics of the corpuscle. Since,however, in most Pacinian cor-puscles there are many more tunicsin the corpuscle than layersof the perineural sheath whichinvests the entering nerve, it
. Quain's elements of anatomy . corpuscle froh the Fig. n MESENTERY OF THE CAT ; STAINED WITHNITRATE OP SILVER. MAGNIFIED. The epithelioid cells of the outermosttunic are shown, and their continuity, atthe peduncle, with those of the correspond-ing layer of the perineurium (from a drawingby Gr. C. Henderson). by Pacini, the layers of the peri-neurium successively become con-tinuous with, or rather expand intothe tunics of the corpuscle. Since,however, in most Pacinian cor-puscles there are many more tunicsin the corpuscle than layersof the perineural sheath whichinvests the entering nerve, it isonly a few of the tunics which arethus continuous; and it will begenerally found that it is the outerones which are so. A certainnumber of the inner tunics aresuperadded therefore, and whentraced towards the nerve-fibre theymay be seen to end with roundedmargins bounding a canal in which the nerve-fibre runs. The latter is accompanied by a little endoneuralconnective tissue which generally contains a number of granular 168 NERAOUS SYSTEM. The nerve-fibre is single as it runs along- the iDeduncle, nnless whenthe latter supports two corpuscles ; it retains the medullary sheath untilit reaches the core, into which the axis-cylinder alone jjasses, freed fromits primitive and medullary sheaths (fig. 169, ). In its course throughthe core it is somewhat flattened, and presents the aj)pearance either ofa pale, finely striated, and very faintly outlined band or stripe, or ofa darker and more sharply defined narrow line ; differing thus iuappearance according as its flat side or its edge is turned towardsthe eye. The contrast in the appearance of the fibre before and afterentering the core is well exhibited after treatment Avith osmic acid, which Fig. 169. Fig. 169.—Part of Pacinian Boor SHOWING THE NERVE-FIBRE ENTERING THE CORE. FrOM AN OS3II0 ACID PREPARATION.(E. A. S.) ms, entering nerve-fibre, themedullary sheath of which isstained darkly, and ends abruptlyat the core
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