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the other which collected blood from the capillaries of the hepatic artery. 
That the collecting veins of the gall bladder and surrounding connective 
tissue empty into the vena portal is easily proved by a simple injection 
of a granular mass into this vessel. But the conclusion that all, or even a 
great portion, of the blood from the hepatic artery is collected by similar, 
put smaller, veins which enter the branches of the vena porte within the 
substance of the liver is a doubtful one, in my opinion. Theile, who made 
a careful study of these vessels, called them the rami vasculares (a ferm 
generally ascribed to Kolliker) and brought forth very meagre evidence 
that they are present in great number. In fact, his best proof is the ob- 
servation occasionally of a vein which arises in the hilus of the liver 
and enters the quadrate lobe before it communicates with a branch of 
the portal vein.” Theile believes that the rami vasculares venosi enter 
very small portal branches because he was never able to see them opening 
into the larger branches after they had been cut open. The presence of 
these branches, he claims, explains why an injection into the hepatic 
artery enters the portal vein and why an injection into the portal vein 
enters the artery as well as the hepatic vein. 
My own injections speak decidedly against internal roots to the portal 
vein, except those that arise from the gall bladder and that neighborhood, 
and can be recognized with the naked eye. After the arterial branches 
once enter the substance of the liver all of their twigs, including those 
of the capsule, communicate directly into the capillaries of the lobule, 
and from there are collected into the hepatic vein. It is usually stated 
that the portal branches are distributed under the capsule and collect the 
blood of that region, but this is incorrect. If a liver is injected with 
two granular masses of different colors, one into the hepatic vein and 
the other into the portal, it will be found that in all cases it is always 
the branches of the hepatic vein which come to the surface of the liver 
and spread out between the meshes of the arterial plexus. 
From our present knowledge of the vascular system of the lobules we 
can easily understand how these three sets of vessels communicate freely 
at this point. In order to test this question in another way, I injected 
whipped blood into the artery of a fresh liver and found that three-fourths 
of it came out of the portal vein and one-fourth out of the hepatic vein. 
In another experiment the arterial pressure was kept constantly at 100 
mm. Hg. with the same result as above. Then upright glass tubes were 
“® Theile, Handworterbuch d. Physiologie, II, 1844, p. 342. 
