Ultrastructural Studies on the Development of Oil Cells in Litsea pungens Comparative anatomy of oil cells and mucilage cells in the leaves of the Lauraceae in China Comparative studies on leaf structure and oil cells of the Magnoliaceae in China ANATOMICAL STUDIESON THE DEVELOPMENT OFOIL CELLS IN LITSEA PUNGENS Anatomical studies on the development of oil and mucilagecells in Cinnamomum longepaniculatum STUDIES ON THE DISTRIBUTION AND STRUCTURE OF OIL CELLS IN LITSEA TSINLINGENSIS The relationship between ultrastructure changes and produce of the oil during the oil cell development in Liriodendron chinense Studies on the development of oil cells in Liriodendron chinense DEVELOPMENTAL ULTRASTRUCTURE OF OIL AND MUCILAGE CELLS IN CINNAMOMUM LONGEPANICULATUM Structures, Components and Functions of Secretory Tissues in Houttuynia cordata