PERIPHERAL NERVE TERMINATIONS. 



365 



finer non-medullated system of branches appear 

 which innervate the epithelium and terminate in 

 varicosities, discs, or minute granules that lie in appo- 

 sition to epithelial 

 cells. Similar free 

 terminations occur 

 in tendons, and liga- 



Connective '-tissue 

 capsule. 



Fig. 257. Tactile cells from the bill of a 

 duck. 





Nerve fiber. 

 __ Epithelial cells. 



ments, and other 

 fi b r o u s connective 

 tissue. 



2. Tactile Cells. These are also called Grandry's 

 corpuscles, and may be found in the duck's bill 



just beneath the 

 gum epithelium. 

 The cells are of 

 epithelial origin, 

 oval, and meas- 

 ure about 50 //in 

 diameter. One 

 to five cells are 

 surrounded by a 

 connective-tis- 

 sue capsule. 

 These cells are 

 superposed on 

 each other, with 

 their long axes 

 always parallel 

 to the surface of 

 the bill. A me- 



dullated nerve fiber may be traced to the cap- 

 sule, which it penetrates and then becomes non- 



- Nucleus of lamellae. 



End-cell of core. 

 Lamellae. 



Axis-cylinder in core. 

 Cubic cells of core. 



Termination of medul- 

 lary sheath. 



Axis-cylinder of 

 nerve-fiber. 



Medullary sheath of 



nerve-fiber. 



Neurilemma and sheath, 

 of Henle. 



Fig. 258. Corpuscle of Herbst from bill of 

 duck (Bohm and Davidoff). 



