A pure line of Hubbard squash was used for the investigation. In the development of the anther the pollen mother cells are formed from a single longitudinal row of cells of the primary sporogenous layer in each anther lobe. During early diakinesis a perinuclear zone is formed. From the perinuclear zone as well as from the interior of the nucleus fibers are formed which constitute the multipolar spindle. There are twenty bivalent chromosomes at the heterotypic division. Counts in root tip cell showed forty somatic chromosomes. During diakinesis a callose wall is secreted around the mother cell. When the heterotypic division has been completed a special wall composed of callose is formed just inside of the original mother cell wall. Quadripartition of the mother cell is effected by partition walls which originate on the inner surface of the special wall and grow centripetally.
Proceedings of the Iowa Academy of Science
©1925 Iowa Academy of Science, Inc.
Castetter, Edward F.
"Microsporogensis in Cucurbita maxima,"
Proceedings of the Iowa Academy of Science, 32(1), 265-266.
Available at: https://scholarworks.uni.edu/pias/vol32/iss1/36