204 ELEMENTARY BIOLOGY. [CHAP. 



d. The liver: a great brown two-lobed mass; its 

 left lobe the larger and subdivided into two. 



e. The lungs: the posterior ends of these may be 

 seen as sacculated pouches, one on each side of 

 the liver, but they are frequently not visible 

 until the latter organ has been removed. 



f. The stomach: a small portion of this is seen pro- 

 jecting beyond the lower left border of the 

 liver. 



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 (rectum} 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. 



/. The fat masses: long slender yellow 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 R. 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 075^- sodic chloride 

 solution and examine with -| obj. 



