THROMBOPLASTIC FACTORS IN PLATELETS AND RED BLOOD CELLS: OBSERVATIONS ON THEIR CHEMICAL NATURE AND FUNCTION IN IN VITRO COAGULATION *

Abstract

Although the existence of blood platelets had been known for many years it was not until 1882 that Bizzozero (1) called attention to the role of platelets in blood coagulation. Morawitz (2), twenty years later, was among the first to con- sider the specific chemical contribution of the platelet to the clotting process.