284 



AXIMAL PHYSIOLOGY. 



[LESSOX 87. 



geneous, although, when treated with acetic acid, they exhibit cell 

 nuclei (a). 



1274. In addition to nerve tubes, which, as before remarked, are 

 common to all nerves, ganglions possess solid corpuscles, liable to 

 much variety of shape ; these have been (erroneously) called " gan- 

 glion globules," but when removed from the tissue many of them 

 present an irregular figure, and are caudate (tailed). A figure of a 

 thin section of a ganglion of the neck (human) 

 is given (Fig. 403) ; these corpuscles are ex- 

 tremely numerous, and, when seen in their nat- 

 ural situation, have a reddish appearance. 



FIG. 404. 



FIG. 405. 



Sympathetic ganglion of Corpuscles from the gray substance Nerve of B. Americana, 

 the neck, human. of the spinal chord, human. 



Removed from the tissue with which they aBe connected, these cor- 

 puscles are very variable in size and shape. 



1275. The ganglion corpuscles are common to the gray or corti- 

 cal substance on the external surface of the Brain, and of all the 

 ganglia, and the corresponding gray matter in the interior of the 

 human spinal chord. A view of these corpuscles, obtained from the 

 latter situation, is given in Fig. 404 ; in addition to their caudate 

 terminations, these corpuscles also present nuclei. 



1276. The remarkable constancy in the structure of nerve and 

 ganglion in the animal kingdom has been adverted to, and illustra- 

 tions obtained from a class as low as the Insects will be sufficient to 

 prove the statement. A portion of a nerve given off from the last 



FIG. 406. (caudal) ganglion of a Cockroach (B. Ameri- 



cana} is given in Fig. 405 ; the Neurolemma 

 (nerve sheath) is distinctly seen on either side 

 (a, a), and within it the nerve tubes containing 

 the white substance* 



1277. A section of the caudal ganglion of 



Ganglion, B. Americana, the' same insect (Fig. 406) displays the nerve 

 tubes greatly reduced in size, and the crowded ganglion corpuscles 



