スギモクの異常卵と半胚の起原について

抄録

Coccophora Langsdorfai (Turn.) Grev., a Fucaceous alga, sometimes bears eight-nucleate abnormal eggs (Fig. 1 a, b) together with normal eggs composed of one central nucleus. The abnormal eggs so much resemble those of Sargassum as they could not be distinguished from the latter. After fertilization, just like Sargassum, seven of the eight nuclei gradually degenerate to disappear with advance of cleavage remaining one large active nucleus, which takes part in the embryo development. The active nucleus, however, is accustomed to be distributed to the basal cell (Fig1c) at the time of the first cleavage which takes place without nuclear division. As a result, the subsequent cleavage is restricted to the basal half, to form a half embryo with a large vacant apical cell (Fig. 1 f).