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Survival and morphogenesis of the enucleated fragments of Acetabularia has been studied after their reconstruction from the cell membrane and the endoplasm. Membranes and endoplasms of different species as well as of the same species but from plants in different functional states and with different regenerative abilities were combined. It was shown that inability of plants for growth and morphogenesis was due to the membrane state. When reconstructing anuclear fragments from membranes and endoplasms of different species or the same species but from plants in different functional states, a phenomenon of membrane-endoplasm incompatibility was found.

The biosynthesis of nuclear RNA, its transport from the nucleus to the cytoplasm and distribution in the cytoplasm were studied in Acetabularia mediterranea under different light conditions. It was shown that the nuclear RNA incorportate 3H-uracil more rapidly in the darkness and the transport of labeled RNA from the nucleus slowed down after the transfer of plants in the cold medium in the darkness. To study the distribution of nuclear RNA in the cytoplasm, the 3H-uracil labeled nuclei were transplanted in the rhizoids of unlabeled plants, the dikaryons obtained were kept for different time in the light and in the darkness and the content of 3H-RNA was determined in different stem regions. It was shown that the transport of 3H-RNA in the cytoplasm is slowed down in the darkness and it is distributed by the basal-apical gradient. RNA is rapidly accumulated in the apical stem zone in the light and redistributed afterwards in the basal stem zones. The problem of relationship between the polarity and nuclear RNA distribution in Acetabularia is discussed.