VIII 



LIVER 



133 



The submucosa of the stomach is traversed by a narrow 

 band of unstriped muscle, the muscularis mucosce, formed, 

 like the main muscular layer, of an outer layer of longitudinal 

 {l.m.m) and an inner of circular {c.m.ni) fibres. 



A muscularis mucosae is also present in the intestine, but as it is very 

 thin, it may easily be overlooked. 



The Liver. — Sections of the liver show it to be made up 

 of innumerable large, polyhedral cells (Fig. 41, c), which are 



Fig 4t. — A, portion oi a section of the frog's liver ; B, smar portion of the same, 

 showing the origin of a bile-duct, 

 h. c. blood-capillaries, in section ; b.p, bile-passages ; c, liver cells ; (/, smallest 

 bile-duct ; -nu. nuclei. (After Hoffmann.) 



so arranged as to bound extremely fine channels or bile- 

 passages {b.p). These are found to open into one another, 

 and finally to discharge into definite tubes (B, d), lined with 

 epithelium. These, in their turn, unite into larger and larger 

 tubes, which form the hepatic ducts and ultimately open into 

 the common bile-duct (p. 68). 



The liver-cells are glandular and secrete the bile, which, 

 as it is formed, drips into the bile passages and passes into 



