HEPATIC VEINS. NERVES OF THE LIVER. 95 



surrounded by a considerable quantity of cellular substance, 

 and thus arranged are partially covered with peritoneum. The 

 cellular substance which invests them continues with them into 

 the liver, and is more particularly connected with the vena 

 portarum. It is called Glisson^s Capsule, and was supposed 

 to have some contractile power, which assisted the circulation 

 of the vena portarum ; but that idea is now altogether abandon- 

 ed. The hepatic v^eins, which receive the blood of the hepa- 

 tic artery and the vena portarum, open into the anterior part 

 of the vena cava, where it is in contact with the liver. Gene- 

 rally there are three of these veins, but sometimes there are 

 only two ; in which case one of them is formed by two others, 

 which unite immediately before they open into the vena 

 cava. It is to be observed, that the various branches of these 

 veins do not accompany those branches of the vena portarum 

 or hepatic artery to which they correspond, but form very 

 large angles with them. This is probably owing merely to 

 their termination in a part so distant from that in which the" 

 artery and the vena portarum originate ; but it is very different 

 from what occurs in other glands. 



The Nerves of the Liver are derived from the semilunar 

 ganglions of the splanchnic nerves. From these many nerves 

 proceed, which form a net-work denominated the solar plexus. 

 From this plexus many threads are sent off, which form a net- 

 work that is divided into the right and left hepatic plexus. 

 These plexuses surround the hepatic artery and the vena por- 

 tarum, and accompany them in their ramifications throughout 

 the liver, being enclosed by Glisson's capsule. They receive 

 some threads from the stomachic plexus, formed by the par 

 vagum. Although the number of nervous fibres is very con- 

 siderable, their bulk, compared with that of the liver, is very 

 small. 



The Lymphatics of the Liver are extremely numerous ; and 

 those in that portion of the peritoneum which invests the liver 

 may easily be rendered conspicuous : for by pressure the in- 

 jected fluid can be forced from the trunks and large branches 

 into the small ramifications, in opposition to the valves. When 



