Liver tissue was taken from 14 patients after massive sporozoite inoculations with a Panama strain of Plasmodium falciparum. The tissue was fixed in Carnoy's fluid, serially sectioned, and stained with a colophonium-Giemsa method.
Exo-erythrocytic parasites were found in the material derived from the patient receiving the heaviest inoculations. This patient had been inoculated on four successive days with a total of 8,516 mosquito bites and 1,403 salivary glands intravenously. The mosquitoes used averaged 86.8 per cent infected. Biopsy was done at laparotomy three to six days after inoculation. A total of about 125 parasites was found. The characteristics of these parasites indicate that they are part of the exo-erythrocytic phase of malaria. They are similar to those found by Shortt and his associates for this species of malaria.
1345 Greene Street, Augusta, Georgia.
We express our appreciation to Dr. Edward Cardwell, pathologist, Veterans Administration Hospital, Columbia, South Carolina, and Dr. James H. Peers, Pathology Laboratory, National Institutes of Health, Bethesda, Maryland, for their critical examination of some of the preparations.