Malaria parasite life cycle, illustration. Malaria is a disease presenting as severe cyclic fevers. These are caused by the Plasmodium falciparum parasite, which is transmitted into the bloodstream by mosquito bites. These light micrograph views illustrate the stages of growth of a malarial parasite. (1) A normal red blood cell; (2-18) trophozoites; (19-26) schizonts; (27, 28) macrogametocytes; (29, 30) microgametocytes. Illustration by Gertrude H. Nicholson for the US National Institute of Allergy and Infectious Diseases. Published in 'The Primate Malarias' (1971).