Meiotic Cytokinesis of Cannabis

Abstract

1. Counts made in the pollen mother cells of Cannabis sativa show that the reduced number of chromosomes in this species is ten. 2. The reduction division commonly occurs during the period from sunrise to noon. Although mitotic figures can be found in material collected during the afternoon or evening, they are comparatively rare. 3. The heterotypic division is easily studied, and chromosome counts are most easily made during the anaphase of this division. The behavior of the chromosomes is normal, and no unusual features were noted. 4. Little can be learned concerning the individual chromosomes during the homotypic division, because of the massing of cell elements and the rapidity of the division. 5. There is no morphological evidence that any one of the ten chromosomes is a sex chromosome. 6. The method of cytokinesis is by furrowing. The furrows appear at the periphery of the cytoplasm and at points equidistant from the mother cell nuclei. These furrows extend rapidly to the center of the mother cell, ...