STUDIES ON AMITOSIS OF EPIDERMAL CELL AND SPECIAL EFFECT OF 2, 4-D IN THIN CELL LAYER CULTURE OF Begonia rex-cultorum Cytohistological Study of Morphogenesis in Thin Cell Layer Culture of Ovaryof Lilium‘Star Gazer’ Cytohistological Study of Morphogenesis in Thin Cell Layer Culture of Ovaryof Lilium‘Star Gazer’ ORIGIN OF FLORAL BUDS IN TOBACCO PEDICELS CULTURED IN VITRO Floral Buds Induction in Thin Cell Layer Cultures of Tobacco Plants and Study on the Floral Gradient