PIGEON. 121 



mesenteric), an unpaired vein from 

 the lower part of the intestine. 

 (dd) The sciatic vein, from the leg ; open- 

 ing into the hypogastric vein near 

 the junction of the middle and pos- 

 terior lobes of the kidney, 

 (c) The renal veins, bringing blood from the 

 kidneys, a larger vein from the pos 

 terior lobes, and a smaller vein from 

 the anterior lobe. 



2. The hepatic veins from the liver ; they join 

 the post cava near its entrance into the 

 right auricle. 

 O. The hepatic portal system. 



1. The gastric veins, two small veins from the 



left side of the gizzard to the left lobe of 

 the liver. 



2. The portal vein, sending a branch into the 



right and a branch into the left lobe of the 

 liver, formed by : 



(a) The gastro-duodenal vein from the right 



side of the gizzard, duodenum, pancreas, 

 etc. 



(b) The anterior mesenteric vein, from most of 



the small intestine. 



(c) The posterior mesenteric vein from the large 



intestine, etc. 



The portal vein receives blood through a small 

 vein from the spleen. 



