抄録
Gelidiun, one of the important marine products of Japan, has been studied by many authors concerning its propagation. But, on the matter of the life-history of this alga, the investigation has not yet been fully done. Therefore I set about to clear out some points of this problem, especially, the germination and development of this seaweed at the first step udder a special adjustment planned by Mr. S. MIYAGI. The results of my observations may be summarized as follows:-
Season of the spore-formation : The sporophytes mature earlier than the gametophytes; tetraspores liberate from the mother plants from June to August and carpospores from August to October as a rule, but some of the plants ripe in May and some in November.
Development of the new plants : The new plants germinate in summer and at first they develope to small creeping fronds with many small buds growing out here and there. And these buds begin to grow up to erect fronds which form the reproductive organs afterwards in them.
Vicissitude of the plants : The plants mostly grow from winter to early summer and after then they densely branch and form the reproductive organs.
After libration of the spores, the mother fronds still live and grow continuously for a few years, and repeatedly form spores every year.
