In the light microscope, euglenoid mitosis is signaled by the elongation of the nucleolus. This elongation of the nucleolus and concomitant elongation of the nucleus may continue until the nucleus is stretched across the cell. The nuclear envelope then begins to constrict around the center of the elongate nucleus and gives the telophase nucleus a dumbbell shape. In some euglenoids, continued constriction of the nuclear envelope pinches off the nucleus and generates the two daughter nuclei. In other euglenoids, the central portion of the dumbbell only is severed as the developing cleavage furrow moves toward the posterior end of the cell.
Many euglenoids undergo active metaboly, squirming about, during cytokinesis.
The electron microscope gives a more detailed picture of mitosis. The following general description characterizes mitosis in most euglenoids. The nuclear envelope and the nucleolus remain intact throughout the mitotic process. As mitosis proceeds, microtubules appear within the nucleus, often near the nuclear envelope. Although chromosomes may group near the equatorial plane of the nucleus, a true metaphase plate is never formed.