1. The virus of yellow fever has been found to survive in artificial culture media for at least 12 days at a temperature of 35°C. No visible growth has been present and no reproduction of the virus has been demonstrated.
2. Infections have been obtained in rhesus monkeys with two strains of virus in quantities as small as 0.00001 cc. of infectious blood, and with one strain in an amount probably as minute as 0.000001 cc.