An investigation of the clearance of bacteria and colloids from the blood stream of mice has shown that both living and inert particles require serum factors (opsonins) in order that they may be phagocytosed by the macrophages of the reticuloendothelial system. It has been demonstrated that after the injection of a large dose of colloid there is a depletion of these serum opsonins which appears...

Erythropoietic and reticuloendothelial functions in bone marrow were found to be identically distributed between various bones and within individual bones in the dog.

The cells of the reticuloendothelial system are often regarded as barriers against the development and growth of malignant tumors. Experimental substantiation of this has been obtained by attempts to suppress the functions of these cells by so called blockade methods, and by stimulation of these Cells for the purpose of increasing their functional activity. The former procedure is considered to...

By JAMES H. JANDL, RICHARD L. SI f sfoNS AND WILLIAM B. CAsTLE T HERE APPEAR to be two mechanisms whereby red cells are destroyed in vivo. First, they may undergo disruption or dissolution within the general circulation, as by the action of immune, bacterial, or chemical lysins, causing the clinical picture of “intravascular hernolvsis.” Second, and more commonly, red cells may be trapped or se...