Abstract
Several investigations have been done about the course of development of fruit in soy bean, but the histological change not yet clear. Soy bean (variety:Chizuka ibaraki No.1) were grown inp ots in out door. The samples obtained 1 day or 2 days interval were fixed with formarin-acetic alohol. The sections were made by Paraffin and Celoidin Method and stained with Gentian violet. The external and internal change of fruits are as follows. (1) Rapid increasing in length and width of fruit appeared during 9 days to 21 days after flowering, but increasing in thick continued during 41 days after flowering. Therefore, the maximum weight is shown in fresh weight at the 30th day of fruit development and in dry weight 36th day. The fresh weight, however, decreased remarkably in the ripening stage. (2) The differentiation of carpel to pod needed about 6 days except the tissues of schrel-enchymous fiber, pulp and inter-epidermis, and the cell elongation in pod continued during 16 days. Outer-integument was the origin of seed-coat and its differentiation was closed on the 16th day after fertilization, but the cell elongation cotinued during 24 days. Inner-integument and nucellus degenerated in the progress of devlopment of embryo and endosperm, and became invisible 2 weeks later. The differentiation of embryo began to occur on the 6th day and continued about 20 days and its cell elongation finished 5 days later. The division of nuolei in endosperm occurred abundantly in the early stage of fruit development, but endosperm was later almost absorped and pressed by the growth of embryo, so that the remaining was scarcely seen inside of seed-coat. No remarkable ohage was found in the tissue of funicle in all stage.
