HuBER, Sympathetic Nervous System. 93 



As already stated, sympathetic cells have only one neur- 

 axis ; the apparent exception to this rule, ganglion cells in the 

 peripheral ganglia of the intestinal canal, as first described by 

 Ramon y Cajal(33), has been shown to rest on faulty observa- 

 tion. Cajal believed that all the processes of these cells were 

 to be looked upon as neuraxes. K611iker(34), as he himself 

 states, was at first inclined to accept Cajal's interpretation of 

 these structures. Dogiel(35) has however quite recently shown 

 that the cells in these ganglia are in structure like similar cells 

 in other ganglia — possessing only one neuraxis, the other 

 branches being dendrites. These observations I can fully 

 confirm, and that on a large number of methylen-blue prepara- 

 tions of the intestinal wall of fishes, of amphibia, reptilia and 

 mammalia, in which the ganglion cells of Auerbach's plexus 

 were well stained. In every instance in which it was possible 

 to make out clearly the shape of these ganglion cells, and trace 

 their respectiv^e processes, only one neuraxis was made out. 



The neuraxes of the sympathetic neurons thus far de- 

 scribed carry efferent impulses. Their mode of termination 

 may be one of the following, — 



1. In involuntary muscle tissue ; 



2. In heart muscle tissue; 



3. In glands ; 



4. In spinal ganglia ; 



5. In other sympathetic ganglia. 



/. Ending in involuntary muscle tissue. — It is now generally 

 believed that all non-striated muscular tissue, namely that of the 

 intestinal canal and the gland ducts in connection with it, the 

 smooth muscle of the urogenital system, the smooth muscle 

 found in the skin, the eye and all vessels, receives its nerve supply 

 from sympathetic neurons. However, only in recent years has 

 this view received its full morphological demonstration; by which 

 is meant, that the staining of a sympathetic neuron in its en- 

 tirety has only in recent years been accomplished. The only 

 existing figure, with which I am familiar, showing a whole neu- 

 ron and its ending in involuntary muscle, is found in an article 



