First-generation merozoites of Eimeria bovis were obtained in large numbers from mature schizonts, after concentration of these by repeated washing and sedimentation. The appearance of living merozoites, as well as their flexing and gliding movements, are described with the use of the phase-contrast microscope. In protargol preparations the anterior portion of the body of merozoites is found to have a cap-like covering with a terminal pore, and a median rodlike structure. Prominent granules occur in the posterior two-thirds of the body, with one granule characteristically located at the posterior extremity. The nucleus is in the posterior one-third of the body. In Feulgen and acridine orange preparations the chromatin is arranged as a ring at the periphery of the nucleus; at irregular intervals there are coarse clumps, usually three to five in number. Numerous small glycogen granules are present in the posterior two-thirds of the body. No sudanophilic lipids were demonstrated. The entire body of each merozoite showed a diffuse positive reaction with the ninhydrin method. These merozoites were found to be similar in certain morphological features to Toxoplasma gondii.