320 The Circulation through the Dog’s Spleen 
ampullae. The last third of the ampulla is difficult to demonstrate, 
but under certain conditions it can be injected, as has been shown by 
Thoma and by me. I find from numerous specimens that its commun- 
nication with the vein is not wide, but is cut up by bridges of tissue 
passing across its lumen before it connects with the vein. This cut- 
ting up is so extensive that in uninjected specimens it has been impos- 
sible for me to find a single ampulla connecting with a vein. In other 
words, it may be better to state that the ampulla rarely reaches the 
vein, but is separated from it by a small band of spleen pulp. When 
the spleen is distended to its maximum and fine granules are injected 
into the artery they pass directly from the ampulla to the vein, 
as well as into the surrounding tissue, for they must pass somewhere. 
This condition is illustrated in Plate I. 
When cinnabar granules and gelatin are injected into the artery for 
a long time with a pulsating pressure most of the granules are found 
in the veins, but a great many are also scattered throughout the pulp. 
According to one’s inclination this becomes an argument either for or 
against an open circulation. When either granules or foreign nucleated 
blood corpuscles are injected into the circulation of. a living animal 
many of them are found between the cells of the spleen pulp, and they 
no doubt entered the pulp-spaces through the holes in the walls of the 
ampullae. Helly believes that the foreign red corpuscles pass from 
the artery to the veins and then through the “‘ homogeneous membrane 
of v. Ebner” in the walls of the veins back into the pulp. That this 
roundabout way is the improbable course I shall show presently. 
It is of decided advantage to inject an organ like the spleen with a 
fluid that will not mix easily with water, and I have tried a variety of 
mixtures of asphalt, turpentine and granules with great success. 
Hoyer” has already used this mixture in the contracted spleen, and 
what I have found in the oedematous spleen confirms and supplements 
his results. When the spleen is distended to its maximum with either 
blood or gelatin the relation of the terminal artery to the pulp is 
shown beautifully by injecting the turpentine-asphalt solution into the 
artery. Some granules of carmine should be added to the solution, 
for they lodge in the fine arterial branches and ampullae, and a few of 
them pass over into the pulp. It is well in making an artificial oedema 
of the spleen to inject the gelatin, to which ultramarine blue is added, 
into the veins. Finally the specimen is hardened in formalin and cut 
1! Hoyer, Internat. Monatschr. f. Anat. u. Physiol., 1887; and Morphol. Arbeiten, 
1894, 276 and 284. 
