336 Olive B. Davies: 



The Oesophagus (Figs. 5. to 10) commences as a fairly 

 straight wide ciliated tube compressed dorso-vertically. This 

 portion of it receives the ducts from the salivary glands ; it 

 then becomes narrower (Figs. 7 , 8, 9) and continues as a narrow 

 tube till it reaches almost the middle of the visceral mass, where 

 it widens to enter the stomach (Fig. 10). It is lined by a 

 mucous epithelium of large, clear cells, with granular nuclei, 

 the nuclei being situated at the ends of the cells away from the 

 lumen of the tube. This epithelium, which is thrown into folds, 

 forms the greater part of the walls of the tube (Fig. 17). 



The Stomach (Figs. 9, 10, 11, 12, 17) is a ver\' large dilated 

 sac on the left side of the posterior end of the visceral mass. It 

 is almost completely surrounded by the liver. Its walls, towards 

 its anterior end, consist of a thin muscular laye-r, lined by a 

 simple epithelium, the cells of which are not well defined, and 

 the nuclei are indistinct. The oesophagus enters the stomach 

 ventrally at its anterior end (Fig. 10), and here the lining 

 epithelium is slightly thrown into folds, and the cells with their 

 nuclei are more definite. At the posterior end (Figs. 11 and 12) 

 the walls become thickened and nuclei of the lining membrane 

 more definite, the membrane itself forming folds. This posterior 

 part is probably the true stomach, the anterior part representing 

 a crop. Under a high power (Fig. 17) the membrane is seen 

 to consist of long narrow cells with large granular nuclei. Also 

 there are other cells which are vacuolated. Outside the mem- 

 brane is a muscular layer. The stomach receives tlie liepatic ducts. 



The stomach opens into the Intestine which runs up between 

 the liver and the hermaphrodite gland (Figs. 9, 10, 11, 12, 17) 

 along the dorsal surface of the visceral hump, dorsal to the 

 hermaphrodite gland, and opens into the rectum (Figs. 9 and 

 10), which runs forward betAveen the hermaphrodite gland and 

 the body-wall to open to the exterior, just behind the opening 

 of the ureter, by the pulmonary opening. The lining membrane 

 of the intestine (Fig. 17) is very like that of the stomach, but 

 there are no vacuoles nor a definite muscle larger in the intes- 

 tine. The intestine is smaller in diameter than the stomach, 

 but it dilates to form the rectum. 



The Salivary glands (Figs. 8, 9, 10) lie on either side of the 

 oesophagus, at the anterior end dorsal to it, but further back 



