NERVES. 375 



one can only regard these ganglions as special little nervous 

 centres performing, with respect to certain functions, the 

 same office as does the cerebro-spinal centre for the other 

 functions. These reflections naturally occur to the mind 

 when one sees the cavity of the tubes or elementary nerve- 

 fibres given off from the spinal cord, or from the encephalon, 

 merge into the cavity of the ganglionary globules at one of 

 their poles, and reappear at the opposite pole of the globule 

 in the same manner that they entered. 



" Setting out from a globule (cell) these nerve tubes pro- 

 ceed to lose themselves in the organs. Thus, those peculiar 

 cells, the agglomeration of which constitutes the ganglions of 

 nerves, are no other than organs which are interposed be- 

 tween the origin of the nerve tube and its termination at a 

 determined point of its course, and, perhaps, there is more 

 than one upon each tube : they interrupt it in its course to 

 allow it once more to reappear ; they change it, they modify 

 its structure at a point to immediately restore it. 



" The authors who have hitherto written upon the subject 

 have not observed the entrance and exit of each elementary 

 tube at the two opposite poles of each globule, but only the 

 one or the other. It is this circumstance which has led them to 

 consider each of these ganglionary globules as a little nervous 

 centre of origin for each tube. 



" There is yet another fact still more important than the 

 first, which has not been pointed out by anatomists who have 

 studied the structure of nerves. 



" They have all described but one order of globules : there 

 are, nevertheless, two which differ, the one from the other, in 

 numerous characters, deduced from the consideration of size, 

 form, contents, walls, &c. One of these orders of globules is 

 always in connexion with the elementary nerve tubes of 

 animal life or the large tubes, &c. The other is associated 

 especially with the elementary tubes of organic or sympathetic 

 life, or with the small tubes., &c. One never finds the large 

 tubes communicating with the second order of globules, and 

 reciprocally the small tubes are never in connexion with the 

 poles of the globules of the first order. 



