386 THE LIVEE. 



that intestine, and three or four inches below the pylorus, as already 

 described. 



Varieties. — ^The liver is not subject to gi-eat or frequent deviation from its 

 ordinary f onn and relations. Sometimes it retains the thick rounded f oiin which 

 it presents in the foetus ; and it has occasionally been found without any divi- 

 sion into lobes. On the contrary, Soemmerring has recorded a case in which the 

 adult liver was 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 jioi-tion, forming a sort of acccs.wnj 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 pait 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. Dkect 

 communications by means of small ducts (named hei^ato-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 siibject. 



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. 



The liver has two coverings, viz., a serous or peritoneal, already 

 sufficiently referred to, and a proper areolar coat. 



The areolar ov fibrous coat invests the whole gland. Ojiposite 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 con- 

 tinuous witli the delicate areolar tissue which lies between the small 

 lobules of the gland. At the transverse fissure it becomes continuous 

 with the capsule of Glisson, by which name, as already noticed, is 

 designated a sheath of areolar tissue which surrounds the branches of 

 the portal vein, hepatic arter}^ and hepatic duct, as they ramify in the 

 substance of the liver, and which becomes more delicate as the vase.ular 

 branches become smaller. 



Hepatic lobules. — The proper substance of the liver, which has a 

 mottled aspect when closely observed, is compact, but not very firm. 

 It is easily cut or lacerated, and is not unfrequently rui)tured during life 

 from accidents in which other parts of the body have escaped mjury. 

 When the substance of the liver is torn, the broken surface is not 

 smooth but coarsely granular, the liver being composed of a multitude 

 of small lobules (figs. 21-i and 275), which vary from bftlf- a line t o a 

 line in diametei" (1 — 2 millimetres). — V ■ ■' 



These lobules are closely packed polyhedral masses, and in some 

 animals, as in the pig, are completely isolated one from another by 

 areolar tissue continuous with the fibrous coat of the liver and with the 

 capsule of Glisson ; but in the human subject, and in most animals, 

 although very distinguishable, they are not completely insulated, being 

 confluent in a part of their extent. Notwithstanding this the lobules 

 of the human liver are sufficiently marked out by interlobular fissures, 

 although these are incomplete. 



