324 



ANATOMY OF VERTEBRATES. 



Nerve of the palm, 

 with Pacinian cor- 

 puscles, Human, 

 ccxxvin. 



214 



a pedicle and capsule, with a canal and central cavity. A single 

 213 nervous fibre, fig. 214, n, leaves its fasciculus with 



a portion of the nerve-sheath, ib. b, and proceeds 

 to the centre of a series of concentric capsules, 

 of a nucleated fibrous tissue. The nerve, n, on 

 entering the central cavity, loses its white sub- 

 stance, and, at the opposite end of the axial cavity, 

 terminates by a tubercular enlargement. An 

 arterial twig, a, accompanies the nerve-fibre along 

 the pedicle, and divides into capillaries, which form 

 loops in some of the intercapsular spaces. The 

 central cavity contains a clear fluid : it varies much 

 in shape. 



Analogous bodies were discovered by Savi, 

 arranged in linear series, bordering the anterior 

 part of the mouth and nostrils, and extending 

 over the surface of the fore-part of the elec- 

 trical organs in the Torpedo; they are appended 

 to and appear to be terminal developements of the filaments of 



the fifth pair of nerves. Each 

 follicle, fig. 215, is formed of two 

 larger capsules, f and g, which 

 adhere together near the fibrous 

 band, c, c, supporting and fixing 

 the organ ; it contains a granular 

 substance, e, on which lies the 

 nerve- twig, b, d, transmitted from 

 the nerve, a. This twig commonly 

 receives a smaller anastomosing 

 filament, k, from a contiguous 

 follicle. Sometimes two nerve- 

 twigs pass from the main branch 

 to the same follicle, in which case 

 it contains two distinct granular 

 masses. These follicles are de- 

 veloped from ganglionic or sensory 

 branches of the fifth nerve. No 

 proper pacinian corpuscles have 

 been observed in connection with 

 this nerve, nor with the glosso- 

 pharyngeal, the portio dura, or 

 any purely motor nerve. 



Pacinian corpuscle, on mesentericnerre of -cat. Besides the Savian COrpUSCleS 



Magu. cuxxix. 



