NERVE ENDINGS IN CONNECTIVE TISSUE 131 



penis, prepuce, and clitoris. In some of the smaller end bulbs 

 found in the tendons, the mucous membranes, and in certain por- 

 tions of the skin, the nerve fibre fails to divide but ends near the 

 distal extremity of the bulb in a small fusiform end knob. 



IV. PACINIAN CORPUSCLES ( Vater's corpuscles, Vater-Pa- 

 cinian corpuscles, lamellar corpuscles). These are among the 



largest of the nerve end organs. 



^^jjjj^-^- They assume the form of a large 



ffit ovoid thickening, placed upon 



^^| 1;^ the end of a nerve fibre. The 



Pacinian corpuscle consists of a 

 thick lamellated connective tissue 



FIG. 130. A PACINIAN CORPUSCLE IN 



LONGITUDINAL SECTION, SHOWING A 

 NETWORK OF SPIRAL ELASTIC FIBRES. 



Weigert's elastic tissue stain. Highly 

 magnified. (After Sala.) 



a 



FIG. 131. AXIAL SECTION OF A CORPUSCLE 

 OF HERBST FROM A DUCK'S TONGUE. 

 a, medullated nerve fibre ; 6, naked axial 

 nerve fibre with a bulbous end ; c, niu-k-i uf 

 the core ; d, inner concentric capsule ; e, nu- 

 clei of the outer lamellated capsule, x 380. 

 (After Sobotta.) 



coat, and a central granular protoplasmic core which is pierced 

 by the nerve fibre. The medullated nerve fibre enters the axis of 

 the corpuscle, its perineurium becoming continuous with the 

 superficial capsule of connective tissue. The nerve fibre on en- 

 tering the core loses its medullary sheath, and after traversing a 

 greater or less portion of the core divides into two to five 

 branches which end near the distal pole in a disk-like expansion. 



