450 MR. C. H. O'DONOGHUE ON THE 
2. The Posterior Lieno-gastric Vein | Pl. I1., P.L.G.] is formed 
dorsally to the gut by the union of the posterior splenic and 
posterior gastric veins, and it runs from this junction to the 
posterior end of the pancreas and along the right dorsal edge of 
this gland, until it unites with the posterior intestinal vein to 
give rise to the hepatic portal vein. 
2.1. The Posterior Splenic Vein | P\.I1., P.S.] is fairly large and 
situated dorsally to the posterior end of the cardiac division of 
the stomach. It collects blood from the ‘posterior portion of the 
spleen, and it receives in addition one or two small branches from 
the stomach. 
2,11. The Median Gastric Vein [P\. II., M.G.] is also fairly large, 
and it is formed by the union of several branches from the 
posterior dorsal region of the cardiac division of the stomach. 
It; leaves the stomach-wall at the point where the lieno-gastric 
artery joins it, and it runs by the side of this artery until it 
unites with the posterior splenic vein. 
3. The Pancreatic Veins are a number of small tributaries that 
flow into the hepatic-portal vein in its course along the edge of 
the pancreas. 
4, The Gastro-Intestinal Vein [Pl. I1., G.I.] is a short vein, 
hidden away in the fold between the pylorus and intestine, which 
commences about the middle of the anterior edge of the pancreas 
and runs along this edge into the hepatic-portal vein. It is 
formed by the union of the intra-intestinal, the anterior lieno- 
gastric, and anterior intestinal veins, and in addition receives one 
or two branches from the pyloric thickening. 
4. i. The Intra-Intestinal Vein [Pl. II., I.1.] is a large vein 
bringing back the blood from the spiral valve. ‘The valve is 
extremely well supplied with large capillaries, and numerous 
branches in each fold feed the intra-intestinal vein which runs in 
the central core of the spiral valve. It perforates the wall of the 
intestine at the anterior end of the spiral valve close against the 
pyloric valve, and it emerges from the intestinal wall in the sharp 
bend between the intestine and the pyloric thickening, where it 
quickly unites with the anterior intestinal and anterior lieno- 
gastric veins. 
A. ii. The Anterior Intestinal Vein | Pl}. I1., A.I.] is of moderate 
size, and originates in the line of insertion of the first fold of the 
spiral valve in the intestine towards the dorsal side of the latter. 
It follows the valve round and comes through the intestinal wall 
on its ventral side close to the anterior lobe of the pancreas. 
Here it receives one or two branches from the wall of the ventral 
part of the anterior end of the intestine and runs straight to the 
pancreas, where it unites with the anterior lieno-gastric vein. 
4.11. The Anterior Lieno-gastric Vein | Pl. II., A.L.G.] is situ- 
ated between the anterior lobe of the spleen and the pyloric 
division of the stomach, and receives tributaries from both these 
bodies. It arises near the level of the division between the two 
parts of the stomach and runs to the beginning of the bend 
