Abstract: With the somatic cells and pollen mother cells of Vicia faba as material, the cytological and cytochemical aspects of cell plate formation were analysed. Cytochemical tests were carried out with staining methods for polysaccharides and RNA. At the end of anaphase or the beginning of telophase in mitotic cells the spindle region between the two sister groups of chromosomes is transformed into the phrag moplast. The cell plate is formed from small granules, which fuse at the equatorial plane within the phragmoplast. The phragmoplast extends laterally, growing through the cytoplasm on both sides, and with its extension the cell plate is finally formed across the cell. When stained by PAS reaction, the phragmoplast of somatic cells shows a faintly pink color. The cell plate gives a strong staining reaction for polysaccharides. The metaphase spindle of somatic cells is stained a rich red by methyl-green-pyronin and is clearly distinguishable from the cytoplasmic area. The phragmoplast is rich in RNA and the cell plate also contains abundant RNA. In metaphase and anaphase of the first meiotic division, the spindle formation is regular, but there is no phragmoplast formed at the end of' division. In early telophase of the first meiosis, at the equatorial plane of the spindle can be seen a membraneous structure, which seems to be the first stage of cell plate formation. It appears only at the equatorial plane of the spindle, but does not extend centrifugally on both sides and it finally disappears at the end of the first meiotic division. This structure is negative in the staining reaction for polysaccharides and RNA. The present authors consider that the cell plate cannot accomplish its development at least partly because of absence of polysaccharides and RNA. In metaphase and anaphase of the second meiotic division, the spindle is formed, but no phragmoplast appears. After the four daughter nuclei have become organized, a spindle is reformed between every two nuclei, making a total of six spindles. At the equatorial plane of every spindle one can see the formation of the cell plate, which gives Positive staining reaction for polysaccharides and RNA. Constriction furrows then start at the periphery of cytoplasm and proceed inward along the cell plate until they meet at the center, so that there is a simultaneous division of the protoplast into four microspores. The chemical nature of the small granules or vesicles, described previously by other authors, from which the cell plate is formed and the mechanism of the formation of the cell plate is briefly discussed.