1914.] NATURAL SCIENCES OF PHILADELPHIA. 415 



they may l)e considered to have one or more distinct openings into 

 the sinus venosus. Followed caudad, the postcava may he tracetl 

 through the large right lobe of the liver, from which it receives 

 several l^ranches. Emerging from the posterior border of the liver, 

 it is seen to extend caudad, in the median line, as a rather incon- 

 spicuous vessel that receives blood from the reproductive organs 

 and the kidneys that lie close on either side of it. 



The hepatic portal vein, h, has the usual distribution for that 

 vessel. Entering the liver in the neighborhood of the bile duct, it 

 receives first O'.e., nearest the liver) a small branch from the pan- 

 creas, pv; near the pancreatic are one or two branches from the 

 stomach, g, and a branch from the spleen, sp. A short distance 

 caudad to these vessels are two or three mesenteric veins, m, leading 

 from the mesentery and small intestine. Caudad to the mesen- 

 teries, the portal system may be seen as a vein of diminished caliber, 

 i, leading from the posterior part of the small intestine and from the 

 large intestine. 



The connection, mentioned by Bronn, between the rectal ranch 

 of the portal vein and the caudal vein could not be demonstrated. 

 After entering the liver, the portal, of course, breaks up into capil- 

 laries, and the blood thus distributed is recollected by the cap- 

 illaries of the hepatic veins above mentioned. 



The internal epigastric veins, ep, are, perhaps, the most conspicuous 

 vessels of the postcaval system. When the ventral abdominal wall 

 of the animal is removed, they may be seen extending forward from 

 the pelvic region, on each side of the body, to enter the posterior 

 edge of the liver. The epigastric of the right side enters the large 

 or right lobe of the liver, where it breaks up into capillaries; the 

 left epigastric sends its main branch into the left lobe of the liver, 

 but also sends a branch over to enter the right lobe. 



Following the epigastrics caudad, they are seen to receive vessels 

 from nearly all parts of the posterior region of the body. The left 

 epigastric, which extends across the ventral side of the stomach, 

 receives from that organ four or five branches, g^; while the farther 

 removed right epigastric receives only one or two branches from the 

 stomach. Posterior to these gastric veins the epigastrics receive 

 one or more veins, b, from the body wall and skin. Posterior, 

 again, to the last-named, veins each epigastric receives, in the pelvic 

 region, a large vein, the iliac, il, which receives, in turn, a vein from 

 the pelvis, pi, and continues down the thigh and lower leg to the 

 foot as the femoral, f, the chief vein of the posterior appendage. 



