NERVES. 377 



same elementary tubes, but only in different proportions, we 

 see that we cannot with Reil, Bichat, &c. acknowledge two 

 nervous systems independent of each other. This opinion is 

 founded on the communications of the great sympathetic with 

 the spinal nerves ; on the fact of nerves being furnished to 

 the abdominal diaphragm of birds, exclusively by the great 

 sympathetic (Sappey) on the partial and successive substitu- 

 tion of sympathetic nerves for spinal and encephalic in a great 

 many vertebrata." 



The above highly interesting observations of M. Robin 

 need confirmation, and it is to be hoped that microscopic ana- 

 tomists will direct their attention to the subject. In the 

 many examinations which I have made of ganglia, I have 

 never recognised the presence of two orders of ganglionary 

 cells, nor have I ever perceived any attachment between the 

 tubes and cells. I would remark, however, that I have made 

 no examination of the ganglia and their constituent cells 

 since the publication of the researches of M. Robin. There 

 is one defect in the abstract of the author, of which we have 

 given a somewhat literal translation, viz. that the distinctive 

 characters of the two orders of ganglionary cells are not 

 recited : it will be observed also that no mention is made of 

 their occurrence in either the brain or spinal cord : from this 

 I should judge that M. Robin was not acquainted with the 

 delicate cells described by me in Part X. of this work, as 

 existing in vast numbers in the white substance of the cere- 

 bum, cerebellum, spinal cord, and nerves of special sense 

 wherever this occurs. 



