While there we delivered babies, performed clinical services, and undertook several public health surveys, including the first malaria survey done in that region. Different people had been imported into the country to serve as laborers in the sugar plantations, and they, along with the indigenous American Indians, provided a richly heterogeneous population. Their responses to the many infectious agents in the environment were very different. This experience was recalled in later years when I became interested in the study of inherited variation in susceptibility to disease. Nature operates in a bold and dramatic manner in the tropics.
Biological effects are profound and tragic.
The manifestations of important variables may often be readily seen and measured, and the rewards to health in terms of prevention or treatment of disease can be great. As a consequence, much of our field work has been done in tropical countries. It is difficult to explain the fascination of Bellevue. In the days before widespread health insurance, many of the city's poor were hospitalized at Bellevue, including many formerly middle class people impoverished by the expenses of chronic illness. The wards were crowded, often with beds in the halls.