THE BABBIT. 123 



10. Turn the stomach and intestines over to the right (of 

 the animal), and observe a pink tube, the main artery, 

 or aorta, running along the middle of the dorsal wall 

 of the abdomen. Following this backward, find a 

 branch which subdivides and sends branches to the 

 stomach, liver, and spleen. Farther back a branch is 

 given off to the intestine; follow it as it branches 

 through the mesentery ; this is the anterior mesen- 

 teric artery. Find a branch, the renal artery, of the 

 aorta running to the dark-colored, bean-shaped, left 

 kidney; finally, the dorsal aorta divides into the two 

 common iliacs, extending toward the hind limbs. 



11. Turn the stomach and intestines to the left, and 

 observe the two veins running forward from the hind 

 limbs; these are the external iliac veins, and by 

 their union they form the vena cava inferior. 



12. Observe the branches derived from the right and 

 left kidneys, the renal veins. Compare the positions 

 of the right and left kidneys. 



13. Trace the" vena cava inferior to the liver. Observe 

 the vein which gathers the blood from the intestines, 

 the mesenteric vein ; the mesenteric vein is joined 

 by a vein coming from the spleen, the splenic vein, 

 and by the gastric -vein, from the stomach; these 

 form the portal vein, running to the liver; this vein 

 distributes the blood through the liver ; the blood is 

 re-collected and empties into the vena cava inferior 

 through the hepatic veins, which are almost wholly 

 concealed by the liver. 



14. Turn the liver forward, and find on its posterior 

 surface the dark bile-sac. The bile-duct, by which 

 the bile is conveyed into the intestine, as also the 



