抄録
The behavior of membranes in the cell during the postmeiotic mitosis was observed with the aid of an electron microscope. The postmeiotic mitosis in microspores is essentially similar to the premeiotic one (Maruyama 1963) in behavior of the cellular membranes. In late prophase, the nuclear envelope breaks down into pieces of cisternae, which mix with the cytoplasmic cisternae. These cisternae, again, differentiate into the nuclear envelope, the plasma membrane and the cisternae in the cytoplasm in telophase.
However, the distribution and movement of these cell components in postmeiotic mitosis is different from those in the premeiotic one. The cisternae concentrate only in one of the polar region of microspore at metaphase, where they take a polarized arrangement towards the ventral cell wall. Because of an uneven distribution of the cell components, the cell plate is laid down closely to the generative nucleus. This unequal cytokinesis seems to lead to a marked differential development of the two nuclei, generative and vegetative, in a pollen grain.
