62 ELEMENTS OF NERVOUS TISSUE. 



costal, and sacral nerves, and, finally, in the great sym- 

 pathetic plexus which surrounds the abdominal aorta. 

 f The cor P usc ^ e f Meissner,* or tactile corpuscle, is a 

 minute microscopical organ which occupies the inte- 

 rior of some of the papillae of the true skin. To get 

 a view of them, it is necessary to make very delicate 

 sections of the skin of the palmar surface of the last 

 phalanges of the fingers or toes, and to apply dilute 

 acetic acid to the section under the microscope. Its 

 shape, like that of the Pacinian corpuscle, resembles 

 an ellipse (PL XXIII. fig. II. 6). Its structure con- 

 sists of a faintly striated substance studded with plas- 

 matic nuclei (fig. II. 9) arranged transversely. At 

 the inferior, or attached extremity of the corpuscle, a 

 nervous filament is seen applying itself to its surface, 

 in the inequalities of which it seems to lose itself by 

 describing tortuous curves which are only occasionally 

 visible. Whether it ends by becoming continuous with 

 the substance of the corpuscle, or by simple division, 

 or by forming a loop, has not as yet been made out. 

 Kolliker has found these tactile corpuscles in the 

 papillae of the vermilion borders of the lips, in the 

 fungiform papillae of the point of the tongue, on the 

 nipple, the glans penis and clitoris ; but they are 

 encountered in greatest number in the skin covering 

 the last row of phalanges of the fingers and toes. 

 Nervous ceiiu. Nerve cells, or corpuscles, vary exceedingly both in 

 size and shape. In all of their forms they present, 

 however, every element of a perfect cell. Thus they 

 have a very delicate cell-wall, so thin and delicate, in 



* Successor to Rudolf Wagner in the chair of Physiology at Got- 

 tingen. (Ed.) 



