196 ELEMENTARY BIOLOGY. [XIII. 



g. The intestine : a convoluted tube, continuous with 

 the stomach, and slung by a delicate membrane, 

 the mesentery: posteriorly the intestine ends in a 

 dilated portion {rectvm) which runs into the 

 pelvis. 



h. The urinary bladder : a thin-walled bilobed sac 

 (which may or may not be distended) appear- 

 ing just in front of the pelvis. 



i. The fat masses : long slender yeUow processes 

 appearing on each side of the liver. 

 In R. temporaria, the urinary bladder is much 

 more deeply lobed and also much larger propor- 

 tionately, than in H. esculenta. 



7. The liver. 



a. Study its form more closely. (6. d.) 



b. Raise its lower border; between its two lobes 

 will be seen a small greenish sac, the gall-bladder, 



c. Carefully cut away the liver, except its deepest 

 part, close to the venous sinus. 



d. Tease out a bit of liver in OYS^ sodic chloride 

 solution and examine with ^ obj. 



a. Numbers of polygonal granular cells (hepatic 

 cells), with oil-drops in them, will be seen. 



yS. Treat with acetic acid: a nucleus, or sometimes 

 two, will be rendered apparent in each of the 

 cells. 



8., The stomach, intestine, pancreas and spleen. 



a. Gut away the front of the pelvis with a stout 

 pair of scissors, taking care not to injure the 

 urinary bladder: pass a probe from the anus, 



