THE VASCULAR ARRANGEMENTS OF THE MAMMALIAN SPLEEN

Abstract

1. The circulation through the splenic pulp is an open one, but the Malphigian follicles have closed capillaries. The rate of flow is sluggish in certain areas, notably about the follicles. 2. The ellipsoids are collections of intensely phagocytic mononuclear cells, occurring at or near the termination of the penicillar arteries of the spleen of certain animals. These cells are embedded in a fine reticular framework which acts as a filter for foreign particles. 3. Ellipsoids do not occur in the rabbit. 4. The size of the ellipsoids depends largely upon the need for such tissue at the time. 5. They are not perfect one‐way valves. 6. In the spleen of the cat and dog phagocytosis of Indian ink particles is carried on largely by cells of these structures. 7. After phagocytosis and migration of the phagocytes, regeneration of the ellipsoids occurs by proliferation of the cells at the termination of the penicillus. 8. Marked hyperplasia of the ellipsoids may result from injection of suitable amounts of foreign particles. I wish to express my thanks to Professor JOHN TAIT for assistance during the prosecution of this investigation and in preparation of the manuscript. The expenses of the research were in part defrayed by a grant from the James Cooper Fund of McGill University for Research in Experimental Medicine.