Primary Exoerythrocytic Schizonts of a Mammalian Plasmodium as a Source of Gametocytes

IN infections of mammalian malaria induced by sporozoites, the first indication of infection in the vertebrate host is the presence of exoerythrocytic schizonts in the parenchymal cells of the liver. After growth for 2–15 days, the time varying according to the species of parasite, each tissue schizont produces several thousand merozoites which, when released into the blood, invade erythrocytes. It is generally assumed that there are then one or more schizogonic cycles in the red blood cells before some of the merozoites from the erythrocytic schizonts grow into sexual forms, the gametocytes.