A variety of chick embryo tissues infected with exoerythrocytic stages of Plasmodium fallax were grown under sheets of cellophane dialysis membranes in Rose multipurpose chambers. The parasites thus cultivated lived for extended periods of time in an environment so favorable to the chick embryo tissues that many of the cells retained some of their characteristic morphology and function. In addition pre-erythrocytic infections were initiated in chick embryo spleen cultures by introducing P. gallinaceum sporozoites from Aedes aegypti mosquitoes under the membranes. Mature segmenters were seen within 48 hours. The parasites and cells thus cultivated were easily studied by phase contrast microscopy and were photographed.