I92I.] N. Annandale & R. B. S. Seweu, : Vivipara. 



227 



Fig. 6. — Vivipara bengalensh, view of inner 

 wall of gnstric cavity after removal of superfi- 

 cial wall, itd., openings o( hepatic ducts ; 

 int., intestine ; ;-., rectum. 



gradually tapers towards its lower end. Running across the 

 posterior wall is a doube fold, of which the upper lip is often 

 much more prominent 

 than the lower. Between 

 these two folds is a nar- 

 row gutter into which the 

 ducts of the right and left 

 lobes of the liver open. 

 The junction of stomach 

 and intestine is very 

 clearly defined owing to 

 the different character of 

 the lining mucous mem- 

 brane. The stomach is 

 lined by tall columnar 

 ciliated cells, which give 

 the wall a soft velvety 

 appearance, whereas the 

 intestinal wall has a yel- 

 lowish colour and is 1 ined 

 with a laj'er of chitin 

 which gives it a smooth 

 bluish metallic look. 



The liver, owing to tJie 

 bulging of the stomach 

 on its outer surface and 



the passage through it internally of the oesophagus, is incom- 

 pletely divided into three lobes, an apical, occupying the upper 

 turns of the spire, and a right and a left lobe inferiorly. The 

 organ has a golden brown colour, which is, however, frequently 

 obscured owing to heavy pigmentation of the overlying skin. It 

 is a racemose gland, with elongate acini the tips of which reach 

 the surface. Each acinus is hollow and is lined with a columnar or 

 cubical epithelium. Each lobe is furnished with a separate duct, 

 that of the upper lobe opening into the left part of the cardiac 

 portion of the stomach, while the ducts of the right and left lobes 

 open on the posterior wall of the pyloric cavity between the folds 

 noted above. According to Leydig these folds probably serve to 

 regulate the flow of bile. 



The intestine passes forwards and to the right in the penul- 

 timate body- whorl and then turns sharply back again, forming a 

 loop which overlies the pericardial cavity. In the first part of 

 its course the lumen gradually narrows : it is lined by a yellow- 

 coloured epithelium covered with a thin chitinous layer and 

 running along its posterior aspect is a gutter with fleshy lips which 

 are pigmented brown. At the apex of the loop, the character of 

 this gutter becomes somewhat modified and the right-hand fold 

 becomes proportionately larger and now appears to form a longitu- 

 dinal ridge or typhlosole projecting from the posterior wall. The 

 intestine having again reached the liver turns sharply forwards 



