Abstract: | SYNOPSIS. Nuclear division and trophozoite structure and function were investigated in Vahlkampfia lobospinosa. During karyokinesis the nucleolus remained present and divided to form polar masses. Chromatids separated and were directed to the polar masses by spindle fibers within an intact nuclear membrane. No interzonal body was formed. Trophozoites consistently contained and extruded a rod-like structure 10–15 × 1–2 μm. Although it was found in other areas of the cell within the cytoplasm, this rod most frequently protruded from the uroid. |