公孫樹前胚期ノ核分裂ニ就テ

抄録

1. During the successive division of nuclei in the formation of proembryo of Ginkgo the size of nucleus decreases with each division, the fusion nucleus being 85-100μ, while the nucleus after seventh division 20-25μ in diameter.
2. During the prophase of the nuclear division of the early proembryo, considerable amount of deeply stainning basophilic granules are found among the spireme thread. They are neither of a definite form, nor of a constant number and are distinguished from the mitocondria or plastids by the fact that they are found only in the‘atractoplasm’** (spindleplasm, ‘Spindelraum’). These granules represent chromatin which is eliminated during the prophase. As the chromosomes form the equatorial plate these eliminated chromatin granules are found scattered mostly toward both poles, and in a later stage, they partly form larger masses of less basophilic nature, and smaller fragments, both finally disappearing.
3. The chromatin-elimination in mitotic division in the proembryo is found only in its early developmental stage, in which the mitotic figures are of huge dimentions. The writer observed the phenomenon up to the 32-nucleate stage. It seems that the chromatin-elimination has a close relation with the diminution of the nucleus.
4. The relation between the basochromatic elimination-granules and the nucleoli is not yet clear.