560 



THE SKIN. 



of their own. Hoyer discovered, by means of silver-staining, a system of dark 

 brown lines, analogous to that in the endothelia. The medullated nerve-fiber 

 enters the corpuscle at one pole, and gradually loses its myeline investment, 

 while the myeline sheath is lost in the structure of the concentric lamellee. 

 The axis-cylinder terminates at the distal pole of the corpuscle as a simple 

 knob, or it bifurcates into two branches, each of which may also exhibit a 

 terminal knob. Around the axis-cylinder is found a granular layer with nuclei. 

 Pacinian corpuscles are most numerous along the nerves of the fingers and 

 toes, less numerous in the palmar and plantar surfaces and in the vicinity of 

 larger articulations in the subcutaneous tissue of the nipple, penis, and 

 clitoris, also along the branches of sympathetic nerves, more especially behind 

 the pancreas, in the dura mater, the periosteum, etc. 



The tactile corpuscles (Meissner's or Wagner's corpuscles) are 

 ovoid bodies, rarely exceeding 200 M in length, and composed of 



FIG. 233. TACTILE CORPUSCLES IN THE PAPILLAE OF THE 

 SKIN OF THE FINGER-TIP. 



2T, medullated nerve-fiber; T, tactile corpuscle; C, connective-tissue sheath ; P, pigment- 

 layer of the rete mucosum. Magnified 500 diameters. 



spiral fibers with small nuclei. Around them a somewhat denser 

 connective-tissue capsule is seen. One or two medullated nerves 

 enter the corpuscle at one pole, their myeline sheath being lost in 

 the fibrous mass of the corpuscle. The axis-cylinder divides into 

 a number of delicate fibrillae, running with the spiral fibers : 



