20 GENERAL ANATOMY OF THE FROG. 



a. The gall-Wadder is a small spherical sac lying between 

 the riu'ht and left lobes of the liver. 



"b. The bile duct is a slender tube leading from the liver 

 and gall-bladder to the duodenum, into which it opens 

 about half an inch beyond the pylorus, and on the 

 inner or concave side of the loop formed by the 

 duodenum and stomach. The distal half of the bile 

 duct traverses the pancreas : it has rather thick white 

 Avails and is easy to see ; the upper half is more 

 slender and more difficult to trace. 



To trace the hile duct turn the liver forwards so that the point 

 of attachment of the gall-hladder is clearly see7i ; and slightly stretch 

 the duodemcin hy a pin passed through the pylorus. Determine the 

 position of the two ends of the hile duct from the description given 

 above, and dissect with a scalpel cdong the line thus indicated. 



To see the opening of the hile duct, slit up the first three quarters 

 of an inch of the duodenum along its convex horder and wash out 

 its contents : squeeze the gall-hladder so as to drive the hile along 

 the duct into the duodenum : note the point at which it enters, and 

 insert a hristle throicgh the opening into the duct. Notice also 

 the strong wavy transverse folds of the onucous memhrane of the 

 duodenum. 



3. The Pancreas. 



The pancreas is a whitish irregularly lobed mass lying in the 

 loop between the stomach and duodenum, and best seen by 

 turning the whole loop forwards. The pancreatic ducts are 

 numerous and open into the bile duct, which passes through 

 the pancreas to reach the duodenum. 



Cut through the mesentery along its attachment to the intestine : 

 uncoil the intestine, leaving it attached at hoth ends, and spread it 

 out on your dissecting hoard : measure the lengths of the several 

 portions and draw them to scale. 



F. Other Abdominal Viscera. 



1. The Kidneys are two flat elongated oval bodies of a red 

 colour attached to the dorsal body wall, close to the middle line, 

 one on each side of the back-bone or vertebral coliunn. They 

 lie in the large lymph space behind the peritoneum. (See Fig. 2, 

 p. 17.) 



