IF any biologist requires a problem which will exercise to the full his patience and experimental skill, he could get it from the monograph "Infectious Anæmias due to Bartonella and Related Red Cell Parasites", by David Weinman (Trans. Amer. Phil. Soc., Philadelphia, New Series, 33, Part 3, 243–350; 1944). Weinman was parasitologist to tne Harvard Expedition to Peru in 1937, which finally established the fact that Bartonella bacilliformis is the eause of both Oroya fever and Verruga peruviana (Verruca peruviana, Verruga peruana), both of which are sometimes called Carrión's disease. Carrión, one of the pioneers of the study of these South American diseases, died of Oroya fever after inoculating himself with verruga material.