62 LETTERS TO BROTHER JOHN. 



organs. It extends from the base of the scull, 

 on each side of the vertebral column (backbone), 

 through the neck, chest, and abdomen, as far as 

 the coccyx (that is, the lower extremity of the 

 backbone), forming, from above to below, nume- 

 rous ganglia : those in the neck are few in number ; 

 but in the rest of its course it generally forms one 

 ganglion between every two vertebrae (bones of 

 the back) : these are severally connected, by one 

 or more filaments, with each other, and with all 

 the nerves of the spinal marrow ; and the upper- 

 most cervical ganglion (ganglion of the neck) is 

 connected with most of the cerebral nerves (nerves 

 of the brain). Lastly, it detaches filaments to the 

 viscera (organs of the belly and chest) ; and those 

 which are distributed to the abdomen (belly) form 

 connexions with a numerous set of ganglia in this 

 cavity, which are placed about the trunks of the 

 large vessels." Thus, Mr.Green traces it no higher 

 than the base of the scull : but an anatomist has 

 recently, if I mistake not, traced it completely 

 round the brain ; and thence downward, on either 

 side of the spine, until that portion of the nerve 

 which descends on one side of the spine unites 

 with that descending on the other side, at the ex- 

 treme lower point of the backbone. During its 



