142 MAMMALIA. 



posterior surface of the stomach. Although there be some variation in the size and 

 number of the branches given off by the par vagum, they are very similar to those in 

 the jaguar. After sending branches to the thoracic viscera, the two trunks do not 

 separate into so many large branches as in man, but combine into two principal cords 

 of unequal size ; and although they do not form so intricate a plexus as in man, they 

 give off numerous filaments, which cover the outer surface of the oesophagus, and are 

 extended in some measure to the cellular membrane and the aorta; the smaller or 

 anterior cord, after passing through the diaphragm, sends branches to the lesser 

 omentum in the baboon, calf, and other animals, to form the left hepatic plexus ; but 

 in the dog, these pass almost immediately between two lobes of the liver on the left 

 side for the same destination ; the other branches of the anterior cord follow the 

 anterior surface of the smaller curvature of the stomach, as in man, and communicate 

 with branches of the right hepatic plexus. The larger or posterior cord, whether it 

 forms one or two portions on the oesophagus, before it pierces the diaphragm, gives 

 branches to the large extremity and posterior surface of the stomach ; but a con- 

 siderable part of it intermixes with the coeliac plexus, from which some of its branches 

 may be traced to the beginning of the large intestines. In ruminating animals, both 

 cords give branches to the supernumerary stomachs ; but with the exception of their 

 larger size, they are the same as in man and other animals. In one baboon, two 

 branches of the right trunk were joined into one behind the oesophagus, and then 

 combined with the portion of the left trunk to form the larger or posterior cord ; but 

 in another baboon, one of these branches from the right trunk joined the posterior 

 cord to pass to the coeliac plexus and the stomach, the other descended separately 

 also to pass to the coeliac plexus and stomach. In the ass, the anterior cord of the 

 par vagum is very small ; it gives some filaments to the stomach and others to pass on 

 the small omentum to the liver, where they communicate with branches of the right 

 hepatic plexus. A great portion of the posterior cord forms a thready expansion, 

 part of which passes in branches to the stomach, and the rest to the coeliac plexus. 



In the porpoise the par vagum communicates with the sympathetic, but is 

 otherwise separate from this, as in the baboon, rabbit, and others ; it gives off a small 



