1. The number of pollen grains per pollen sac, the development of tapetum and archesporial cell were studied in some species of the genus Polygonum. 2. One archesporial cell arises from the hypodermal layer of the anther primordium. 3. The anther in this genus has always four pollen sacs, and a pollensac is surrounded with the four layers; epidermis, endothecium, transitional layer and tapetum. 4. The tapetum develops from the transitional layer. Nuclear division of the tapetal cell is a mitosis without the cytokinesis, at least in the first division. 5. Concerning the number of pollen grains, this genus can be classified into five types which contain 8, 16, 32, 128 and 256 pollen grains, respectively, in a pollen sac. Therefore, they have respectively 2, 4, 8, 32 and 64 pollen mother cells, and the pollen mother cells of the former three types are usually arranged in row in a pollen sac. 6. It seems to be probable that in Polygonum persicaria a pollen sac contains only four pollen grains. Literature cited
1) The process of digestion of starch grains in the growing stigma of Lilium longiflorum Thunb. was observed and shown in Fig. 1. 2) In the immature stigma of Lilium, Antirrhinum, Gladiolus and Hibiscus storage starch grains were found abundantly, but with the progress of maturation the starch grains disappeared. 3) Sugars in the stigma of Lilium and some other flowers were investigated by means of paperchromatography. Sucrose, glucose and fructose were found to exist in the respective stigmas (Figs. 2, 3). 4) By the addition of stigma juice of Lilium to the solution of soluble starch, maltose, glucose and some other sugars were regularly detected, while the color of iodine reaction of this solution turned into yellow brown from blue (Fig. 5). It may be said that tissues of stigma contain some amylase. 5) The localization of amylase in stigma was histochemically investigated. The presence of amylase was demonstrated in all parts of the stigma tissue except vascular tissue, and the activity of the enzymes was found to be highest in the tiptissue and inductive tissue (Fig. 4). 6) The tissues of mature stigma of Lilium have an activity to produce starch grains from Cori-ester. It may be said that there exists some phosphorylase in these tissues. 7) In the mature pollen starch grains are deposited before germination when they are incubated on the sugar media, while germinating pollen which had been freed of starch grain was not found (Fig. 6).