MAMMALIA. 183 



In man, a distinct ganglion generally connects the right phrenic nerve and 

 semilunar ganglion, but only very minute filaments, passing on the phrenic artery, the 

 left. A junction has been observed on the right side in a baboon, but not in any other 

 animal : further inquiry is, however, necessary ; and although in man filaments from it 

 have been traced to the inferior vena cava, yet the greatest portion joins the left 

 hepatic plexus. 



The duodenum, the small intestines and the coecum, and a more or less extensive 

 portion of the upper part of the colon, are furnished by the superior mesenteric plexus, 

 which has a considerable admixture of branches from the par vagum ; in man, the 

 baboon, jaguar, dog, fox, calf, ass, and pig, the remaining portion of the large intes- 

 tines, as far as the rectum, is supplied by the sympathetic. In man and the baboon, 

 the descending portion of the colon has an extraordinary quantity of nerves from the 

 aortic and hypogastric plexuses. The hypogastric plexuses near the bladder and 

 rectum are joined by branches from the third and fourth sacral nerves in man, and 

 similar ones in animals, and although they do not emerge from the same sacral 

 foramina, a mixed power is produced, which is neither altogether voluntary nor invo- 

 luntary, yet capable of performing both functions. Thus a gradual change is made in 

 the nerves throughout the alimentary canal; first, in the great supply of cerebral 

 nerves in the stomach and a less one of the sympathetic ; next, a diminished quantity 

 of cerebral nerves, and an increased one of the sympathetic ; then a supply of the 

 sympathetic only, and afterwards an admixture of this with the spinal nerves, when 

 there is an entire cessation of the proper intestinal secretions and functions ; and lastly, 

 the spinal nerves alone, for the sphincter and other muscles of the perineum and the 

 skin. The kidney is furnished by the sympathetic only, the ureter also receives 

 filaments from this as well as from the hypogastric plexus ; the bladder, which is only 

 a reservoir, and merely secretes mucus, is supplied by the sympathetic and spinal 

 nerves conjoined ; there is nearly the same analogy with respect to the contribution of 

 branches from the sympathetic only for the testes, and the mixed nerves, for their 

 reservoirs, the vesiculse seminales, and their ducts. It may be further observed that 

 the aortic plexus, by dividing into the two hypogastric to become combined with 



