ELECTRON MICROSCOPY STUDIES ON THE NUCLEAR CYCLE OF PHYSARUM POLYCEPHALUM
多头绒泡菌细胞核周期的电镜研究

Nutrional growing stage of Physarum polycephalum Schw. was cell wall-less plasmodia in which numerous nuclei undertook synclironous intranuclear whtosis. in ths paper, the ultrastructural changes of nuclei in the mitohc cycle were studied with electron microscopy. At prophase, chromatin assembled into chromosome thorugh the process of reorganization and condensation, and nucleolus moved from the center to the edge of nucleus and disintegrated at the place near the nuclear membrane.At metaphase, nuclear membrane did not disappear; the mitohc spindle was formed within the nucleus, and the unregular disintegrated nucleolar materials dispersed in the nucleus. After mitosis, the nuclear membrane recovered in the brokened areas;chromosome discondensed into chromatin, and nucleolus was reformed by coalescence.