Each basal body pair is the focus for a cone of microtubules that extends toward and envelops the nucleus. Also, at each basal body pair, new microtubular roots have begun to form. The nuclear envelope initially remains intact, but later dissipates, at which time the microtubules enter the nucleus and become associated with chromosomes. Chromosome condensation is evident at prophase. The nucleolus remains intact.
Chromosomes are small, irregularly shaped and difficult to count.
The number appears to be in th twenties or thirties. The nucleolus is persistent. Chromosome movement at anaphase appears to be due mostly to the separation of the spindle poles. At telophase, nuclei reform, chromosomes decondense, and spindle microtubules disappear. A cleavage furrow is initiated between the basal body pairs and progresses posteriorly until the cells are separated.