In our experience to date, the outcome of inoculations made with Plasmodium falciparum has been distinctly less certain than in the case of those made with Plasmodium vivax, even though in each case the presence of sporozoites in the salivary glands of the mosquitoes was verified after their application. In all except three instances the inoculations reported have been in negroes or colored persons. Failure cannot be attributed to immunity of the patients, as in every instance where an inoculation has been unsuccessful, we have ultimately, by using other mosquitoes (usually infected with the same strain), invariably succeeded in infecting the patient. The uncertain results cannot therefore be credited to qualities of the patients.
After the mosquitoes have matured their infection with Plasmodium falciparum, they are transferred for storage to a Frigidaire kept at a temperature ranging from 3° to 14°C.