抄録
The authors intended to study morphologically and physiologically. the mechanism of occurrence of aborted seeds in soy-bean. 1) The primordia of all ovules in an ovary differentiate simultaneously, regardless of their position in the ovary. However, the developement of embryo-sac is somewhat faster at apical ovules, and also the increased numbers of nucleus are recognized in pro-embryo of apical ovules. Accordingly we suppose that the time of fertilization is earlier in apical ovules. 2) The volume-increase of pods and seeds closely related to their water content, because the curve of increase shown by seed and pod resembles to the curve of water content. Both seeds and pods reduce the water content after 10∼15 days after fertilization, but after 20∼25 days only the seeds continue to reduce their water content, while the pods do not. 3) After fertilization from 8 to 25 days, numbers of embryocell increase conspicuouslly and growth of the embryo-cells proceeds rhythmically repeating alternately the resting and growing paces. 4) A conversion of size among seeds in a pod usually occurs during growth ; that is, in the early stage of embryonal developement, the apical seed is largest, while at the successive stage the basal one became largest, and at the latest stage the central seed is larger than others. Accordingly ripening course of seeds takes turn twice ; and this turning takes place earlier in two-seeded-pod than in three-seeded pod, but takes place later, or does not entirely in pods on plants which grown under unfavorable condition.
