Ehrlich,1 in 1891, was probably the first to note phagocytosis of red blood corpuscles by leukocytes in the circulating human blood. While this phagocytic phenomenon has been observed for the various types of leukocytes, polymorphonuclear neutrophils and eosinophils, the mononuclear cells have been most frequently noted as erythrophagocytes. This report deals with erythrophagocytosis by mononuclear cells.
The occurrence of this condition has been observed in a wide variety of pathologic conditions, but it has never been reported as seen in the circulating blood of a healthy person.
In reviewing the previous reports in the literature on mononuclear erythrophagocytosis, I found that the cases observed by Connal2 were the only ones found in which its occurrence was reported in infancy or childhood. His observations on native South African children were made on malarial patients ranging in age from 1 year upward. He was unable to demonstrate phagocytosed erythrocytes in