186 ALBERT KUNTZ 



tions of the ileum of the dog (fig. 4, C). In these instances, 

 however, no distinct terminal enlargement is apparent, but 

 the terminal part of the fiber breaks up into short delicate 

 branches which spread out over the surface of the proxmial part 

 of the dendrite. Sympathetic fiber-terminations similar to those 

 here described were described by Huber ('97) in other parts 

 of the sympathetic nervous system. 



In the myenteric plexus of the ileum of the dog prepared by 

 the pyridine-silver method, sympathetic fibers were observed 

 which terminate directly on the cell-bodies of large neurones (fig. 

 4, D). A sympathetic fiber terminating in this manner may 

 without difficulty be distinguished from the processes which arise 

 from the neurone because it is more slender than the latter and 

 stains more intensely. Furthermore, the terminal enlargement 

 can not be confused with the cone of origin of any of the proto- 

 plasmic processes. Terminations of sympathetic nerve-fibers 

 on sympathetic neurones similar to those here described were 

 described by von Lenhossek ('94) in Golgi preparations of embryos 

 of the chick. 



Whether the sympathetic fibers whose terminations on sympa- 

 thetic neurones in the myenteric and the submucous plexuses are 

 here described are the axones of neurones within these plexuses 

 or whether they are fibers whose origin is in some center outside 

 the walls of the digestive tube could not be determined. That 

 some of them may represent fibers which arise in more centrally 

 located centers is highly probable. On the other hand, it is 

 highly probable that axones of neurones in either the myenteric 

 or the submucous plexus may terminate on neurones in the same 

 or in the other of these plexuses. 



DISCUSSION 



According to the doctrine of Langley which is still more or less 

 prevalent, the neurones composing the sympathetic ganglia are 

 all excitatory in character. These neurones, whether located in 

 the ganglia of the sympathetic trunks, the prevertebral or the 

 peripheral sympathetic plexuses, are interpreted as links in effer- 



