THE NERVES. 431 



IV. Plexus hcemorrhoidales inferiores, a right and a left, con- 

 nected with the superior plexus of the rectum, receiving branches 

 from the sacral nerves. 



V. Plexus vesicates, ascend partly at the sides of the urinary 

 bladder, partly horizontally forwards to the collum vesicce and to 

 the prostata (plex. prostalici). Filaments pass off from it to the 

 vesiculce seminales, vasa deferentia, and form plex. spermatici, 

 which are connected above with the renal plexus, and continue into 

 the plexus testicularis. 



VI. Plexus cavernosi, arise especially in the pi. prostatici and 

 from branches of the sacral nerves, perforate the fibrous mass 

 about isthmus and bulbus urethrce, and partly cross, as the one 

 enters into the right, the other into the left spongy body. 



In the female, instead of branches for prostate, vas deferens, 

 &c., there are corresponding filaments for uterus and vagina, ova- 

 rium and tuba. 



The posterior and lateral plexus uterini arise, generally, from 

 plex. hypogastr., the anterior on the contrary, generally, from the 

 anterior branches of the third and fourth sacral nerves. They 

 entwine about the veins and enter into the substance of the uterus. 



