SYMPATHETIC SYSTEM. 



319 



210 



From the sympathetic (gastric) ganglion of the Ray. 



CCXXII. 



211 



It consists of ' ganglionic corpuscles,' or ganglion-vesicles, fig. 210, 

 a, b, c, and nerve-fibres, imbedded in a nucleated fibrous tissue. 



The ganglion vesicle may be 

 circumscribed, or be continued 

 into a nerve-fibre, or into two 

 nerve-fibres from opposite poles 

 of the vesicle ; it is termed ac- 

 cordingly ' apolar,' ' unipolar,' and 

 ' bi-polar : ' the last is the most 

 common form, the first probably 

 a genetic stage. When a gan- 

 glion-cell is connected by more 

 than two processes with nerves, 

 it is a ' multipolar cell : ' these 

 are most common in the ganglia 

 of the main cord of the sympa- 

 thetic ; the bipolar cells prevail in the ganglia of the posterior 

 roots of the spinal nerves, fig. 

 201. The nerve-fibres in gang-lions 

 consist of the ' white ' or broader 

 kind, and of the 'grey' or finer kind; 

 there are also still more minute 

 but solid or homogeneous fibres, 

 surrounding- and connecting the 

 true nervous constituents of the 

 ganglion. A nerve on entering 

 a ganglion breaks up into its 

 component fibres, which interlace 

 about the ganglion-cells, some- 

 times winding round them, with 

 plexiform interchanges of fibres 

 from other entering nerves and 

 from the cells. 



Bidder and Volkman 1 give the 

 subjoined magnified view, fig. 

 212, of the 'intercommunicating;' 

 nerve-fibres between a sympathetic 

 ganglion and a spinal nerve in the 

 Frog, h p is the sympathetic, h 

 showing the part next the head ; 

 C P is the spinal nerve, c showing 

 the part next the myelon ; a is a portion of the communicating 



1 CCXII. 



A. Spinal ganglion of the Ray, 40 diameters. 

 B. Portion of the same, dissected, ccxxn. 



