120 



FUNCTIONS OF THE NERVOUS SYSTEM. 



Fig. 15. 



this series of ganglia also may be 

 regarded as belonging to that sys- 

 tem ; and as bearing the same re- 

 lation to the gray fibres ' contained 

 in the cerebro-spinal nerves, as 

 that which the semilunar ganglia 

 have to the nerves of the solar 

 plexus, in other words, acting as 

 their centres of power. 



160. The branches proceeding 

 from the Semilunar ganglia are 

 distributed upon the abdominal 

 viscera ; and those of the Cardiac 

 ganglia upon the heart and the 

 vessels proceeding from it. The 

 latter seem to accompany the arte- 

 rial trunks through their whole 

 course, ramifying minutely upon 

 their surface ; and can scarcely be 

 doubted, that they exercise an im- 

 portant influence over their func- 

 tions. What the nature of that 

 influence is, however, will be a 

 subject for future inquiry. It is 

 so evidently connected with the 

 operations of nutrition, secretion, 

 &c., that the designation of "nerv- 

 ous system of organic life," as ap- 

 plied to this system, does not seem 

 objectionable, provided that we do 

 not understand it as denoting the 

 dependence of these functions upon 

 it. Even in Vertebrata, however, 

 we do not always find the visceral 

 system distinct from the cerebro- 

 spinal. In the Cyclostome Fishes, 

 the par vagum supplies the intes- 

 tinal canal along its whole length, 

 as well as the heart ; and no ap- 

 pearance of a distinct sympathetic 

 can be discovered. In Serpents, 

 again, the lower part of the ali- 

 mentary canal is supplied from 

 the Spinal Cord, and the upper 



A view of the Great Sympathetic Nerve. 1, the plexus on the carotid artery in the carotid foramen; 

 2, sixth nerve (motor externus) ; 3. first branch of the fifth or ophthalmic nerve; 4. a branch on the sep- 

 lum narium going to the incisive foramen; 5, the recurrent branch or vidian nerve dividing into the caro- 

 tid and petrosal branches; 6, posterior palatine branches: 7, the lingual nerve joined by the corda tympani; 

 e. the portio dura of the seventh pair or the facial nerve; 9. the superior cervical ganglion; 10. the mid- 

 dle cervical ganglion; 11, the inferior cervical ganglion; 12, the roots of the great splanchnic nerve 

 arising from the dorsal ganglia; 13, the lesser splanchnic nerve; 14, the renal plexus; 15, the solar 

 plexus; 16, the mesenteric plexus; 17, the lumbar ganglia: 18, the sacral ganglia; 19, the vesical plexus; 

 20. the rectal plexus; 21, the lumbar plexus (cerebro-spinal) ; 22, the rectum: 23. the bladder; 24, ihe pubis ; 

 2o. : the csest of the ileum; 26, the kidney; 27, the aorta; 23, the diaphragm; 29, the heart; 30, the larynx; 

 31 the sub-maxillary gland; 32, the incisor teeth; 33, nasal septum; 34, globe of the eye ; 35, 36, cavity of 

 the cranium. 



24 



