This slide shows a blood smear taken from an individual infected with malaria. Although most of the erythrocytes (red blood cells) on the smear are normal,  note the red blood cell infected with the parasite (indicated by the blue arrow).  The apicomplexan protozoan Plasmodium that causes the disease is an endoparasite that grows and reproduces within infected red blood cells.  During this stage of Plasmodium's complex life cycle shown, the parasite is undergoing schizogony (multiple fission), which results in the production of a number of nuclei (seen as dark spots within the cell).  After cytokinesis  (cell division) is completed, the cell will rupture and release the newly-formed daughter cells that are called merozoites.  It is the synchronous destruction of many erythrocytes and the release of their contents that produce the alternating bouts of fever and chills characteristic of the disease.