NECTURUS 7 



lies between the glutseus and the gracilis and extends from the 

 ileo-ischial region to the fibula. The muscles of the dorsal surface 

 of the shank act as an extensor communis. 



Draw a dorsal view of the limb and the adjacent parts of the 

 trunk, showing the muscles. 



VISCERAL ANATOMY 



Open the abdominal or peritoneal cavity of the injected 

 specimen (coelom) by a longitudinal incision a little to the right 

 of the mid- ventral line, taking care not to injure the under- 

 lying organs or to cut the pectoral or pelvic arches. Make 

 lateral cuts on the right side so that the wall may be folded 

 outwards. See the thin membrane (mesohepar) connecting the 

 liver with the ventral body wall. How far does it extend in 

 either direction? Do you find any blood-vessels in it? 



Now make similar cuts in the other side, cut the mesohepar, 

 and pin out the body walls. Tip the liver to the right, slightly 

 separate the viscera, without cutting or tearing any of the 

 membranes, and draw the parts exposed, as follows: 



The liver, dark-colored and nearly median in position. How 

 many lobes to it? Lift the lobes and find a small vesicle, the 

 gall-bladder, on their dorsal surface. Trace the bile-duct from 

 the gall-bladder to the liver and to the intestine. To the left of 

 the liver is the stomach. Can you distinguish where stomach 

 ends and intestine begins? Cut into the intestine behind the 

 entrance of the bile-duct and carry the incision forward. The 

 abrupt change noticeable in the character of the lining marks 

 the boundary (pylorus). 



Follow the intestine back to the pelvic region. See the 

 lobulated pancreas near the entrance of the bile-duct. Examine 

 the inner surface of the intestine for the opening of its duct. 

 To the left of the stomach is the elongate, dark-colored spleen. 

 Look on either side of the liver in the dorsal part of the ccelom 

 for the elongate lungs. Which lung, right or left, is the larger? 



Lift the intestine and see that it is bound to the dorsal body 

 wall by a thin membrane, the mesentery, and that the stomach 

 is supported in a similar way by a mesogaster. A membrane, the 

 gastro-hepatic omentum, extends from stomach to liver, while 

 liver and intestine are connected by an hepato-duodenal omen- 



