LOBULES OF THE HEPATIC SUBSTANCE. 869 



divided into twelve lobes ; and similar cases of subdivided liver (resembling that of 

 some animals) have been now and then observed by others. A detached portion, 

 forming a sort of accessory liver, is occasionally found appended to the left extremity 

 of the gland by a fold of peritoneum containing blood-vessels. 



The gall bladder is occasionally wanting ; in which case the hepatic duct is much 

 dilated within the liver, or in some part of its course. Sometimes the gall-bladder is 

 irregular in form, or is constricted across its middle, or, but much more rarely, it is 

 partially divided in a longitudinal direction. Direct communications by means of 

 small ducts (named hepato-cystic), passing from the liver to the gall-bladder, exist 

 regularly in various animals; and they are sometimes found, as an unusual formation, 

 in the human subject. 



The right and left divisions of the hepatic duct sometimes continue separate for 

 some distance within the gastro-hepatic omentum. Lastly, the common bile-duct 

 not unfrequently opens into the duodenum, apart from the pancreatic duct. 



STRUCTURE OF THE LIVER. 



Coats. The liver has two coverings, viz., a serous or peritoneal invest- 

 ment, already sufficiently referred to, and a proper areolar coat. 



The areolar or fibrous coat invests the whole gland. Opposite to the 

 parts covered by the serous coat, it is thin and difficult to demonstrate ; 

 but where the peritoneal coat is absent, as at the posterior border of the 

 liver, and in the portal fissure, it is denser and more evident. Its inner 

 surface is attached to the hepatic glandular substance, being there continuous 



Fig. 606. 



Fig. 606. SECTION OP A PORTION OP LIVER PASSING LONGITUDINALLY THROUGH A 

 CONSIDERABLE HEPATIC VEIN, FROM THE PIG (after Kiernan). f 



H, hepatic venous trunk, against which the sides of the lobules (1) are applied ; h, h, h, 

 sublobular hepatic veins, on which the bases of the lobules rest, and through the coats of 

 which they are seen as polygonal figures ; i, mouth of the intralobular veins, opening into 

 the sublobular veins ; i', intralobular veins shown passing up the centre of some divided 

 lobules ; I, I, cut surface of the liver ; c, c, walls of the hepatic venous canal, formed by 

 the polygonal bases of the lobules. 



