Following Schulz's classic description of granulocytic angina in 1922, reports of an apparently primary type of leukopenia have become increasingly numerous. According to the recent statement of Madison and Squier,1over 500 of these cases are now on record. Wells2has quoted Stursberg, Marchand and Blumer as stating that differentiation during life between overwhelming sepsis, so-called aleukemic leukemia and agranulocytosis may at times be impossible. With this in mind it would be helpful to call these cases granulopenia. Kracke3has suggested this term because it places emphasis on the one common observation and accurately describes the characteristic blood picture. Obviously, much would be gained if these conditions could be classified according to the etiology involved. It has long been recognized that benzene is highly toxic to the bone marrow, and benzene poisoning has been extensively studied both clinically and experimentally. It has only recently been suggested, however,