182 



ANATOMY OF VERTEBRATES. 



the Baboon the caecum and about one foot of the colon is supplied 

 by the superior mesenteric plexus, and the remaining five feet of 

 the large intestine by the inferior one. In Carnivora this sup- 

 plies about the terminal half of the large intestine. In the 

 baboon Swan noticed a communication between the right phrenic 

 nerve and the semilunar ganglion. 1 



The trunk, advancing or ascending from each semilunar gan- 

 glion, is an aggregate of cords (' splanchnic nerve,' Anthropotomy), 

 which, perforating the diaphragm, separate to form communica- 

 tions with a variable number of the thoracic ganglions of the 

 sympathetic. In the baboon Swan traced the origins or con- 

 nections of the right splanchnic nerve with two thoracic ganglia 



in advance of the left, this extending 

 over the heads of five posterior ribs, 

 and the other over seven, each ex- 

 panding into a small ganglion at the 

 bottom of the chest. In the hedge- 

 hog the splanchnic nerve extends over 

 the heads of the four last ribs, and, 

 receiving filaments from the sympa- 

 thetic, forms a plexus on the sides of 

 the vertebra?, as in the baboon ; but 

 separates from the trunk of the sym- 

 pathetic higher in the chest. In the 

 jaguar this separation occurs a little 

 above the diaphragm : in the hog at 

 the passage through the diaphragm. 

 But ' these variations do not seem to 

 make any difference either in the for- 

 mation of the semilunar ganglion, or 

 the branches preceding from them.' 2 



Kolliker has given the subjoined 

 view, fig. 137, of the communication 

 of the splanchnic, Spl, with the myelon 

 by the ' rami communicantes ' Re, Br, 

 and with the ganglion of the sympathetic, G, from which it derives 

 its grey fibres. From the trunk of the sympathetic TV and the 

 ganglion the nerve s to the intercostal artery is sent off. 



In Mammals the parts regarded as ' trunks,' or ' main chords ' 3 

 of the sympathetic, form a symmetrical pair extending along the 

 sides of the centrums, forward to the basioccipital, and backward 



1 liv. p. 115. ■ lb. 



3 ' Prolongations,' Swan. liv. passim. 



Sixth thoracic ganglion of sympathetic. 

 Rabbit, l.xxvin-. 



