Additional details of the life history of the chicken coccidium Eimeria mitis Tyzzer, 1929.

Four asexual generations of Eimeria mitis were identified. The first three developed above the epithelial cell nuclei, but the fourth developed above and below. Meronts measured 13.8 x 16.4 microns, 16.1 x 16.4 microns, 12.1 x 14.6 microns, and 9.5 x 12.4 microns, respectively, of generations 1, 2, 3, and 4. They matured at 36, 67, 72, and 88 hr postinoculation (PI) and contain 20-24, 16-20, 10-14, and 7-10 merozoites, respectively. Merozonts measured 7.2 x 1.9 microns, 8.5 x 2.5 microns, 9.6 x 2.0 microns, and 6.75 x 2.75 microns, respectively. The first two types of meronts were deep in the crypts and epithelial cells. The third and fourth types of meronts were along the side and tip of the villi. Gametocytes developed from third and fourth generation. Gamonts were usually below the nuclei of the epithelial cells. Parasitism was primarily in the ileum, ceca, and rectum and also in the yolk-sac diverticulum.