Abstract
1. The authors found in many of the preparations of the bud, that had dropped, the proembryo having been formed by fertilization. Almost every flowers and pods which had dropped were observed to contain immature grains which stopped their devdopment at the end of proembryo stage or at the cotyledonous stage. 2. Flower-drop which took place most frequently seemed to be caused by stopping of development of the seed, in which firstly the elongation growth of embryo cells became inactive, nextly it stopped and, at last, the whole embryo and endosperm deteriorated as shown in figs. 4. 5. 6. 7.
