This book is composed of the collected papers read at the Institute for the Consideration of the Blood and Blood-Forming Organs held at the University of Wisconsin in September 1939. The various subjects and their authors are as follows: Some Historical Aspects of Hematology, E. Meulengracht; The Porphyrins and Diseases of the Blood, Cecil J. Watson; Aplastic Anemia, C. P. Rhoads; Anemia Due to Iron Deficiency, Clark W. Heath; Anemias of Nutritional Deficiency, George R. Minot; The Erythroblastic Anemias, Louis K. Diamond; Some Etiological Factors in Pernicious Anemia, E. Meulengracht; The Nature of Hemolytic Anemia, Russel L. Haden; Experimental Leukemia, J. Furth; Monocytic Leukemia and Subleukemic Leukemia, Claud E. Forkner; The Present Status of Hodgkin's Disease, E. B. Krumbhaar; The Reticulo-Endothelial System, Charles A. Doan; Hematologic and Pathologic Aspects of Infectious Mononucleosis, Hal Downey; Polycythemia, Paul Reznikoff; Marrow Cultures, Edwin E. Osgood; The Present Status of the Blood Coagulation Problem,