Trophozoites develop into schizonts which contain multiple merozoites. The sporozoites grow and multiply in the liver to become merozoites. Trophozoites then mature to schizonts which divide several times to produce new merozoites. There are two generations of schizonts and merozoites which are morphologycally distinguishable. There is a clonal expansion of schizonts and then multiply by merging to form merozoites. Some merozoites differentiate into sexual forms, male and female gametocytes. The trophozoites moult into merozoites, which have a tetrad structure coined a Maltese-cross form. Rather than producing more and more trophozoites, some of the merozoites produce gametocytes. Large schizonts giving rise to 12 or more merozoites. The daughter parasites called merozoites then only infect the RBCs. Eventually, the cells burst, releasing merozoites, which infect new cells. Schizonts of "P. vivax" have up to twenty merozoites within them. These merozoites get released and they attach to the epithelial cells. Some of these merozoites can cause autoinfection by attaching to epithelial cells. The red blood cells are ruptured by the merozoites.