PHYSIOLOGICAL ANATOMY OF THE LIVER 361 



of emergence of the hepatic duct, present frequent anastomoses with 

 each other in their course. 



Vasa Aberrantia. In the livers of old persons, and occasionally in 

 the adult, certain vessels are observed ramifying on the surface of the 

 liver but always opening into the biliary ducts, which have been called 

 vasa aberrantia. These are not found in the foetus or in children. 

 They are appendages of the excretory system of the liver, and are 

 analogous in their structure to the ducts, but are apparently hyper- 

 trophied, with thickened fibrous walls, and present in their course 

 irregular constrictions not found in the normal ducts. The racemose 

 glands attached to them are always much atrophied. 



Fig. 77. Racemose glands attached to the biliary ducts of the pig, x 18 (Sappey). 



I, i, branch of an hepatic duct, with the surface almost entirely covered with racemose glands 

 opening into its cavity; 2, branch in which the glands are smaller and less abundant ; 3, 3, 3, branches 

 of the duct with still simpler glands ; 4, 4, 4, 4, biliary ducts with simple follicles attached ; 5, 5, 5, 5, the 

 same, with fewer follicles ; 6, 6, 6,6, 6, anastomoses in arches; 7, 7, 7, angular anastomoses ; 8, 8, 8. 8, 

 anastomoses by transverse branches. 



Gall-bladder, Hepatic, Cystic and Common Ducts. The hepatic duct 

 is formed by the union of two ducts, one from the right and the other 

 from the left lobe of the liver. It is about an inch and a half (38 milli- 

 meters) in length and joins at an acute angle with the cystic duct to 

 form the ductus communis choledochus. The common duct is about 

 three inches (76 millimeters) in length, of the diameter of a goose-quill 

 and opens into the descending portion of the duodenum. It passes 

 obliquely through the coats of the intestine and opens into its cavity 

 in connection with the principal pancreatic duct. The cystic duct is 

 about an inch (25 millimeters) in length and is the smallest of the three 

 canals. The structure of these ducts is essentially the same. They 



