In a previous paper (1) an observation on the incubation period of Plasmodium vivax was reported, which showed that for several days subsequent to inoculation by sporozoites, the presence of parasites in the peripheral blood stream could not be demonstrated by daily subinoculations of 10 cc. quantities of blood until the eighth day subsequent to inoculation. It appeared desirable to repeat an experiment of this type employing Plasmodium falciparum as the test organism. The results were as follows:
Experiment 109. (a) As a test subject there was selected a Negro male patient (1181) for whom malaria therapy was prescribed. (b) Twelve other Negro male patients requiring malaria therapy were utilized. (c) Anopheline mosquitoes of Lot 729, infected with the Long strain of P. falciparum, were employed for the inoculation of the test patient.
Immediately prior to the inoculation of the test patient 1181, on May 19, 1938, 10 cc. of his blood were removed and injected intravenously into patient B1855.