THE SYMPATHETIC NERVE. 487 



root of the renal artery, contribute to it, and it is also re-en- 

 forced by an addition from the lesser splanchnic nerve. The 

 branches which form this plexus do not anastomose much, till 

 they get near the kidney; they then penetrate into its substance, 

 through the fissure. Some filaments from this plexus go to the 

 capsules renales: others follow the course of the spermatic ar- 

 tery, and constitute the spermatic plexus which goes to the 

 testicle in the male, and to the ovarium in the female. 



5. The Inferior Mesenteric Plexus is a continuation of the 

 solar, on the anterior face of the abdominal aorta. It is much 

 smaller than the superior mesenteric plexus, though it receives 

 continually, in its descent, filaments from the lumbar ganglions 

 of the sympathetic. It forms frequent anastomoses around the 

 root of the inferior mesenteric artery, and near the superior 

 strait of the pelvis, is resolved into two columns of fibres. One 

 column is distributed along with the artery to the rectum, to 

 the sigmoid flexure of the colon, and to the left section of the 

 latter, thereby anastomosing with the colic branches of the su- 

 perior mesenteric plexus. The other column descends into the 

 pelvis, in front of the sacrum, and contributes to form the hy- 

 pogastric plexus, but several of its branches also follow the 

 external and the internal iliac arteries. 



Of the Lumbar Ganglions of the Sympathetic* 



These ganglions are five in number, on either side, and are 

 placed anteriorly on the sides of the bodies of the lumbar ver- 

 tebrae, near the anterior margin of the psoas magnus muscle. 

 Their form is irregular; they are smaller than the cervical gan- 

 glions, but larger than the dorsal. 



The last thoracic ganglion is united to the first lumbar by a 

 small branch, which may be considered as the continuation of 

 the sympathetic. A deficiency of this branch has, however, 

 been several times observed by anatomists; also a deficiency 

 in the connecting nervous chord of the ganglions below. The 

 ganglions themselves are inconstant in their number, being some- 

 times less than five; they vary likewise in their situation. It 

 is to be understood, however, that in a majority of subjects, the 



