SYMPATHETIC NERVES OF THE TERRESTRIAL CARNIVORA. 81 



penicillata, Ictonijx zorilla, Mephitis mephitica, Ailurus fulgens, and 

 Melursus ursinus. 



c. The thoracic cord becomes the main splanchnic nerve, and 

 the others come from the abdominal sympathetic. The remainder 

 of the sympathetic cord appears as a branch of the main splanch- 

 nic in Paradoxurus larvaUis (text-fig. 14 A). In Cants thous 

 (text-iig. 14 B) the main splanchnic cord gives a branch to a 

 ganglion whence the abdominal sympathetic passes caudad, and 

 two long rami communicantes run to the last dorsal and first 

 lumbar nerves. 



Branches of the thoracic cord to the aortic plexus vary in 

 prominence. 



The Solar Plexus varies considerably in details, but it is built 

 on the same general plan in all. It lies on one side of, or is 

 wrapped I'ound the coeliac axis. It has always at least one large 

 ganglion, but smaller ones may be present in addition. It receives 

 the dorsal vagus cord and splanchnic nerves, and its ofishoots 

 accompany the various abdominal arteries, interlacing at their 

 terminations. Sometimes the hepatic and splenic plexuses are 

 apparently given off from the right vagus. Superior and inferior 

 mesenteric ganglia may be present, and these are most marked 

 in Meles meles (text-fig. 14 C). As filaments of the right 

 vagus get into many, if not all, of the offshoots the abdominal 

 organs get a rich supply of both vagus and sympathetic fila- 

 ments. The following list contains an enumeration of the 

 offshoots : — 



1. Phrenic plexus. 7. Renal plexuses. 



2. Gastric ,, 8. Suprarenal plexuses. 



3. Hepatic ,, 9. Spermatic ,, 



4. Splenic „ 10. Ovarian „ 



5. Duodenal ,, 11. Inferior mesenteric plexus. 



6. Superior mesenteric plexus. 12. Aortic plexus. 



All the offshoots are not equally obvious in all the Carnivora. 

 The most variable is the duodenal plexus, which depends on the 

 presence or absence of a large duodenal branch of the superior 

 mesenteric artery (text-fig. 12). 



The Sympathetic Nervous System in Phoccena communis. 

 Swan (1), in his description gives the following data : — 



1 . The pyriform superior cervical ganglion of the sympathetic 

 nerve sends one portion upwards and one downwards. 



2. The sympathetic communicates with the superior laryngeal 

 nerve. 



3. The inferior cervical ganglion on the right side communi- 

 cates with the vagus, but the left one does not. 



4. The thoracic ganglia are well marked, and on the whole 

 larger than in other mammalia ; they give off aortic and 



Proc. Zool. See— 1923, No. YI. 6 



