248 EXCRETION. 



apparently hypertrophied, 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 very much atrophied. Sappey is of the opinion 

 that these are ducts leading to lobules on the surface of the 

 liver which have become atrophied. 1 



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 in length, and joins at an 

 acute angle with the cystic duct, to form the ductus commu- 

 nis choledochus. The common duct is about three inches 

 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 cys- 

 tic duct is about an inch in length and is the smallest of 

 the three canals. 



The structure of these ducts is essentially the same. 

 They have a proper coat, formed of white fibrous tissue, a 

 few elastic fibres, and a few non-striated muscular fibres. 

 The muscular tissue is not sufficiently distinct to form a 

 separate coat. The mucous membrane is always found 

 tinged yellow with the bile, even in living animals. It is 

 marked by numerous minute excavations, and is covered 

 with cells of columnar epithelium. This membrane con- 

 tains numerous mucous glands. 



The gall-bladder is an ovoid or pear-shaped sac, about 

 four inches in length, one inch in breadth at its widest por- 

 tion, and capable of holding from an ounce to an ounce and 

 a half of fluid. Its fundus is covered entirely with peri- 

 toneum, but this membrane passes only over the lower sur- 

 face of the body. 



The proper coat of the gall-bladder is composed of white 

 fibrous tissue with a few elastic fibres. In some of the lower 



1 SAPPEY, op. cit., tome iii., p. 283. 



