1880.] On the local Paralysis of Peripheral Ganglia, Sfc. 427 



Ganglion of the Solar Plexus. 



In the dog, cat, and rabbit the splanchnic nerve on the left side 

 rnns to two chief ganglionic masses. Since the upper of these ganglia 

 sends its nerves chiefly to the cceliac axis and the lower sends its 

 nerves chiefly to the superior mesenteric artery, we may call these 

 respectively the cceliac and superior mesenteric ganglia. From the 

 solar plexus nerve fibres run to the kidney. Usually these are joined 

 by fibres direct from the splanchnic. In the cat and dog there has 

 been in the cases we have examined a lesser splanchnic, running 

 partly to the renal plexus and partly to the solar plexus. The renal 

 ganglia are, as is well known, scattered, but in the dog the chief one 

 often lies underneath the supra-renal body, and in the cat the chief 

 one is placed between the artery and vein on fibres proceeding chiefly 

 from the superior mesenteric ganglion and about ^ inch from it. 



Our experiments upon the connexion of the splanchnic with the 

 ganglia of the solar and renal plexus have been made almost entirely 

 on the left side, and in the following account we speak of the nerve 

 and ganglia of the left side, unless the right side is especially men- 

 tioned. 



When the stomach and intestine are exposed there are usually slight 

 movements of the intestines, and there may be movements of the 

 stomach. When these are absent they may be brought about, with 

 a degree of distinctness varying with the animal, by stimulating the 

 vagus. These movements continue for a short time after the nerve 

 stimulation has ceased. Stimulation of the splanchnic stops the 

 movements, whether they are spontaneous or are occurring as the 

 result of previous vagus stimulation. These facts are well known ; 

 but whether the inhibitory fibres of the splanchnic end in the nerve 

 cells of the solar plexus has so far been guess work. To determine 

 this we have proceeded as in the case of the superior cervical ganglion. 

 Having ascertained that the application of 1 per cent, nicotin or 

 nicotin sulphate to the splanchnic leaves its inhibitory power 

 unaffected, we have painted one or other of the ganglia, or the whole 

 plexus, with a small brush moistened with 1 per cent, nicotin or 

 nicotin sulphate. Mcotin applied to the whole plexus at once abolishes 

 the inhibitory power of the splanchnic, but inhibition, although 

 naturally much less perfect, can still be produced by stimulating the 

 fibres proceeding from the ganglia. Hence the inhibitory fibres of the 

 splanchnic end in the cells of the solar plexus. Further, if the superior 

 mesenteric ganglion be brushed over with nicotin, stimulation of the 

 splanchnic is still able to produce inhibition of the movements of the 

 stomach, but is without any appreciable effect upon the movements 

 of the intestine. On the other hand, when nicotin is applied to the 

 cceliac ganglion, the inhibitory power of the splanchnic upon the intes- 



