1886.] 



on the Sympathetic Nervous System. 



535 



communicantes, which latter, as I have told you, are the only true 

 connections of the cerebro-spinal nerve-centre with the sympathetic. 

 In other words, we have driven home to their origin these visceral 

 nerve-fibres, and we find that they do not arise from any nerve-cells 

 outside the brain and spinal cord, but from a definite nerve-group 

 within the spinal cord. 



Fig. 1. 



Fig. 1. — Diagram of section of spinal cord to show the various groups of 

 nerve-cells in the grey matter, and the formation of a spinal nerve with its 

 sympathetic ganglion. 



1. Cells of posterior horn and somatic sensory nerves. 



2. Cells of Clarke's column and ganglionated splanchnic nerves. 



3. Cells of lateral horn and non-ganglionated splanchnic nerves. 



4. Cells of anterior horn and somatic motor nerves. 



5. Solitary cells of posterior horn and splanchnic sensory nerves. 



We can, I think, go further than this, and say, with Bichat, 

 that two nerve-systems do exist, the one for organic, and the other 

 for animal life. These two, however, are not separate and distinct, 

 but form parts of the same central nervous system. Looking 

 at this diagram of the upper cervical region of the cord, we see 

 that the voluntary striped muscles may be divided into two groups, 

 according to their nerve supply, viz. a group supplied by the 

 anterior (4), and one by the lateral horn of nerve-cells (3), and we 

 know also that these two groups of nerve-cells separate from one 

 another more and more as we pass into the brain region. So that we 

 find for the muscles of the face a distinct separation of two groups, 

 viz. 1, those which move the eyes and the tongue — these are supplied 

 by nerves which arise from the continuation of the anterior horns ; and, 

 2, the muscles of expression and mastication, the nerves of which arise 

 from the continuation of the lateral horn ; and remembering how the 

 smile, the laugh, and the snarl, as well as the action of swallowing, are 

 at the bottom only modified respiratory movements, we see that Charles 

 Bell was not so far wrong when he inserted a lateral or respiratory 

 system of nerves in between the anterior and posterior roots. This 

 insertion is actually to be seen at the upper part of the cervical cord 



