This study of the vital capacity of negroes is a by-product of a hookworm study in a group of about 2,000 white and negro children of school age, in south Alabama. These children were measured carefully to determine the effect of varying intensities of hookworm infection on normal growth and development.1 One of the measurements used in the determination of the physical condition of these children was vital capacity. We were surprised to find that normal negro children had markedly lower vital capacity than white children of the same age, sex and economic status. The groups studied were children of school age (from 6 to 16 years) from the rural districts of Alabama. Their dietary contained sufficient calories but was badly balanced. The white families lived on little farms, side by side with the negroes and on a similar economic level. Hygienic conditions were similar in the two races.