212 



veins may be divided into two classes : namely, those contained in the 

 lobules, and those contained in canals formed by the lobules. The 

 first class is composed of interlobular branches, one of which occupies 

 the centre of each lobule, and receives the blood from a plexus formed 

 in the lobule by the portal vein ; and the second class of hepatic veins 

 is composed of all those vessels contained in canals formed by the 

 lobules, and including numerous small branches, as well as the large 

 trunks terminating in the inferior cava. The external surface of every 

 lobule is covered by an expansion of Glisson's capsule, by which it is 

 connected to, as well as separated from, the contiguous lobules, and 

 in which branches of the hepatic duct, portal veins and hepatic artery 

 ramify. The ultimate branches of the hepatic artery terminate in the 

 branches of the portal vein, where the blood they respectively contain 

 is mixed together, and from which mixed blood the bile is secreted by 

 the lobules, and conveyed away by the hepatic ducts which accompany 

 the portal veins in their principal ramifications. The remaining blood 

 is returned to the heart by the hepatic veins, the beginnings of which 

 occupy the centre of each lobule, and when collected into trunks pour 

 their contents into the inferior cava. Hence the blood which has cir- 

 culated through the liver, and has thereby lost its arterial character, 

 is, in common with that which is returning from the other abdominal 

 viscera, poured into the vena porta?, and contributes its share in fur- 

 nishing materials for the biliary secretion. The paper is accompanied 

 by numerous drawings of preparations made by the author, of the 

 minute structure of the liver, in which the different sets of vessels 

 and ducts were injected in various ways. 



The Society then adjourned over the Long Vacation to the 21st of 

 November next. 



