Within about one hour of being inoculated into the vertebrate host, sporozoites of Plasmodium make their way to the liver or other internal organs and enter cells such as hepatocytes. The sporozoite transforms into a trophozoite, then begins the asexual multiplication process of schizogony. Because this division takes place outside of the circulatory system, it is called "exoerythrocytic" or "pre-erythrocytic" schizogony.
When nuclear division has occurred but cytokinesis has not yet taken place the parasite is called a cryptozoite. After cytokinesis, the numerous individuals are now called cryptozoic merozoites, or metacryptozoites. The metacryptozoites may infect new cells or enter the circulatory system and infect erythrocytes. This photo shows a hepatocyte containing hundreds of metacryptozoites, in a large mass, with the hepatocyte's own nucleus a small sphere to the right of it.