THE NATURE OF THE WALL BETWEEN GENERATIVE AND VEGETATIVE NUCLEI IN THE POLLEN GRAIN OF TRADESCANTIA PALUDOSA

Abstract

Electron‐microscopical studies have revealed the existence of a true cell wall—probably containing cellulose and pectin—between generative and vegetative nuclei in the pollen grain of T. paludosa. The wall is formed by the fusion of pectin vesicles and becomes continuous at the time of its formation with the intine of the pollen‐grain coat. Coincidentally, the inner and outer plasma membranes bordering the newly formed cell wall participate in formation of the plasma membranes of the vegetative and generative cells. Attention is directed to the possible role of the cell wall in facilitating, within the closed system afforded by the pollen grain, the pattern of differentiation that serves to determine the structural and functional properties of the vegetative and generative cells.