Behavior of silver stainable material during mitosis inVicia faba

To reveal the behavior of silver stainable material localized mainly in the nucleoli and nucleolar organizing regions (NORs), the somatic cells ofVicia faba were investigated by silver staining throughout the mitotic cell cycle. Nucleoli of interphase and early prophase nuclei were darkly stained. From late prophase to anaphase the secondary constrictions were discriminated as silver stained NORs and many silver grains appeared throughout the cytoplasm. At late prophase the NOR condensed at the same rate as the chromosome arm. Small spherical bodies and two new nucleoli appeared in telophase nuclei and at the same time the cytoplasmic grains disappeared. On the basis of the above observations on the silver stainable material during each mitotic phase, the behavior of silver stainable material is interpreted.