ON. THE CIRCULATION] THROUGH. "THE PULP OF. THE 
DOG’S SPLEEN. 
BY 
FRANKLIN P. MALL. 
From the Anatomical Laboratory of the Johns Hopkins University. 
WitH ONE PLATE AND ONE TEXT FIGURE. 
Recent researches upon the blood-vessels of the spleen prove definitely 
that the arterial capillaries communicate quite freely with the pulp- 
spaces, but there is still a difference of opinion regarding the presence 
of distinct channels, independent of the pulp-spaces, connecting the 
arterial capillaries with the venous sinuses. It seems that the more the 
subject is investigated the more the two views regarding the circulation 
through the pulp approach each other. <A system of capillaries 
completely closed does certainly not exist, but the pulp-spaces seem to 
have among them larger and more direct channels leading from the 
artery to the vein. These may be likened to larger and more direct 
holes punched through a sponge, which therefore communicate freely 
with one another. 
A number of reseaches by Thoma and his pupils have brought up 
the spleen problem anew, and judging by the methods they have em- 
ployed, these studies will probably lead to a final solution of the ques- 
tion.” The works of Sokoloff and of Wicklein deal mainly with the 
vascular walls in hyperaemia of the spleen and contain many valuable 
experiments, while those of Thoma deal with the relation of the blood- 
vessels to the surrounding tissues when injected with either fluid or 
with granular masses. Thoma says (1899, p. 281): “In den meisten 
Organen ergeben Injectionen der Blutbahn mit den genannten kérnigen 
und gelodssten Farbstoffen keine auffilligen Unterschiede. Die bei der 
Milzinjection hervortretenden Unterschiede mtissen somit als bedeut- 
ungsvoll anerkannt werden. Die Injectionen mit kérnigen Farbstoffen 
beweisen, dass die Milzarterien durch die Verbindungsstiicke unmittel- 
1 Sokoloff, Virch. Arch., 112; Wicklein, Ibid., 124; Kalenkiewicz, Inaug. Diss., 
Dorpat, 1892; Golz, Inaug. Diss., Dorpat, 1893; Thoma, Dorpater Naturfor.-Gesellsch., 
18; Thoma, Verhandl. der. anat. Gesellsch., 1895; and Thoma, Archiy fiir 
Anatomie, 1899. 
