NERVOlfS SYSTEM. 3GI 



aorta from the solar plexus, with the addition of two or three 

 branches from the trunk of the sympathetic. Most of the fila- 

 ments derived from it pass on to form 



The posterior mesenteric plexus ; one that is likewise re-inforced 

 by branches (comparatively large in size) from the sympathetic. 

 It transmits nerves to that part of the colon left unsupplied by 

 the anterior mesenteric plexus, and to the rectum : some few of 

 them also ramify in the substance of the mesocolon, while others 

 penetrate the lymphatic glands seated within the folds of that 

 membrane. 



T/ie hypogastric plexus, situated still further backward than 

 the posterior mesenteric plexus, consists of divers delicate nervous 

 filaments ramifying upon the aorta, and spreading themselves, 

 entangled in cellular substance, about its bifurcation. This 

 plexus is also multiplied by branches coming from the sympa- 

 thetic. The filaments departing from it run to the pelvic viscera 

 and the organs of generation. 



The renal plexus is a more important one : it is produced by 

 the intercommunication of a few filaments from the lesser splanch- 

 nic nerve with the addition of numerous others from the solar 

 plexus. It is found close to the aorta, immediately behind the 

 anterior mesenteric plexus. It conceals the origins of the emul- 

 gent arteries, spreads around them in their passage, and sends 

 filaments in company with their branches into the substance of 

 the kidneys. It also furnishes with nerves the capsulae renales, 

 the renal glands, and the beginnings of the ureters. 



The sympathetic nerve in the abdomen travels over the sides of 

 the bodies of the lumbar vertebrae, below the articulations of the 

 ribs, covered by the crura of the diaphragm, and thus pursues its 

 course into the pelvis. Here likewise it forms ganglia, corre- 

 sponding in number to that of the lumbar nerves ; and from 

 every ganglion issue two filaments, one of which runs to the 

 correspondent lumbar nerve; the other crosses the aorta, and, 

 by joining the aortic plexus, communicates with nerves coming 

 from the sympathetic of the other side. 



From the loins, the sympathetic descends into the pelvis, where 

 it takes its course, laterally, along the body of the sacrum. Five 

 sacral ganglia, corresponding to the five sacral nerves with which 

 they communicate, are found here, and between them run in 

 arches across the sacrum several intercommunicating filaments. 

 In quitting this bone, the nerve grows so small, and becomes so 

 firmly adherent to the ligamentous covering of the os coccygis, - 

 that I have not yet succeeded, to my mind, in ascertaining the 

 precise manner in which it finishes its course: it is said, however, 

 to do so by forming a union with its fellow. 

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