Abstract
Some of the most interesting studies in human malaria in which I have participated have concerned factors of importance in the epidemiology of the disease, especially the conditions under which the infection is transmissible to mosquitoes, and the possible alteration of this transmissibility through the judicious selection and use of antimalarial drugs. One who is engaged in this field of research soon discovers that these conditions can be quite complex and puzzling. For example, the correlation between gametocyte densities in the human host and the infectivity to mosquitoes may be extremely variable, depending on the stage of the infection, the species—or even the strain—of parasite, and many other factors. It is felt that an understanding of these conditions is of considerable importance as an aid to the efforts now underway toward eradication of the disease.