GANGLIA 



FlG. 116. A NERVE CELL FROM 

 A SECTION OF A HUMAN 



GASSERIAN GANGLION. 

 (7, capsule. Nissl's stain, x 500. 



other, especially in 

 sympathetic system, where 

 they were formerly but 

 little understood. In the 

 spinal ganglia Dogiel * 

 describes two types of gan- 

 glion cells: (1) in which 

 the processes are thick 

 and pass out of the gan- 

 glion to become the axis- 

 cylinder of a medullated 

 nerve fibre, and (2) cells 

 with slender processes 

 which break up within 

 the ganglion and whose 

 terminal branches form 

 a pericapsular plexus 

 around the cell capsule ; 

 from this plexus fine end 

 branches penetrate the 

 capsule to form a pericel- 

 lular arborization about 

 the nerve cell itself. The 

 cells of this latter type 

 might be said to serve as 



In its finer structure the ganglionic 

 neurones do not appear to differ in any 

 way from other neurones. The large 

 vesicular nucleus with its distinct nu- 

 cleolus readily distinguishes these cells 

 from those of neighboring tissues. 



Recent studies of 

 the ganglion cells by * 

 Dogiel, Eanvier, and 

 Cajal have done much 

 to explain the re- 

 lations of 

 these cells 

 to each 

 the 



FIG. 117. SCHEMATIC REPRESENTATION OF THE RE- 

 LATIONS OF THE STRUCTURES COMPOSING A 

 SPINAL GANGLION. 



A and B, ventral and dorsal spinal nerve roots ; 

 0, a spinal nerve ; D and J, its ventral and dorsal 

 divisions ; F, its ramus coramunicans. a, nerve 

 cells of the first type, whose neuraxes divide and 

 form the axis cylinder of a peripheral and a central 

 nerve fibre ; 6, nerve cells of the second type, whose 

 neuraxes, n, end in a felt work about the cells of the 

 first type ; s, sympathetic nerve fibres which termi- 

 nate in a basket work about the cell bodies of the 

 second type of ganglion cells. (After Dogiel.) 



* Anat. Anz., 1896. 



