THE NERVOUS SYSTEM. 



461 



well as in the penis of the cat. Each corpuscle is attached by a narrow 

 pedicle to the nerve on which it is situated, and is formed of several 

 concentric layers of fine membrane, consisting of a hyaline ground-mem- 

 brane with connective-tissue fibres, each layer being lined by endothe- 

 lium (Fig. 320); through its pedicle passes a single nerve-fibre, which, 

 after traversing the several concentric layers and their immediate spaces, 

 enters a central cavity, and, gradually losing its dark border, and be- 

 coming smaller, terminates at or near the distal end of the cavity, in a 



FiO. 318. 



FIG. 819. 



FIG. 318. Extremities of a nerve of the flnger with Pacinian corpuscles attached, about the nat- 

 ural size (adapted from Henle and Kolliker). 



FIG. 319. Pacinian corpuscle of the cat's mesentery. The stalk consists of a nerve-fibre (N) with 

 3 thick outer sheath. The peripheral capsules of the Pacinian corpuscle are continuous jwith the 

 outer sheath of the stalk. The intermediary part becomes much narrower near the entrance of the 

 axis-cylinder into the clear central mass. A hook shaped termination with the end-bulb (T) is seen 

 in the upper part. A blood-nessel (V) enters the Pacinian corpuscle, and approaches the end-bulb; 

 it possesses a sheath which is the continuation of the peripheral capsules of the Pacinian corpuscle. 

 X 100. (Klein and Noble Smith.) 



knob-like enlargement, or in a bifurcation. The enlargement com- 

 monly found at the end of the fibre, is said by Pacini to resemble a gan- 

 glion corpuscle; but this observation has not been confirmed. In some 

 cases two nerves have been seen entering one Pacinian body, and in 



