抄録
Already in 1929, I(18) reported preliminarily on this subject, but at that time both experi-ments and observations were. not satisfactory, so that I have continued this study since 1934 at the suggestion of Dr. K. MIYAKE.
As regards the fate of the carpospores, DANGEARD (2) has reported that the carpospores of Porphyra germinate and develop to the protonema-like microscopic plantlets after they are liberated from the mother fronds.
After my observation, anyhow, I think it is not far from the truth to say that the car-pospores of Porphyra tenera KJELLM. germinate soon after the mother frond liberate them, because not only I could easily observe this germination with the fully riped carpospores in the laboratory, but also in nature on the twigs of dead trees or bamboos, which were planted in shallow waters for the culture of the alga, I could find out many germinated young plantlets in the later part of spring-that is the season, for the mother plants, to begin to decay. These plantlets do not grow large during the summer season, and they propagate with monospores repeatedly. The young fronds which germinate in autumn on the twigs of dead trees or bamboos yield monospores which are transformed from the ordinary vegetative cells; and thus multiplication of this alga is done. Thereafter, this plant develops normally, and gives rise to the frond of Porphyra in winter. These facts observed by myself in nature were quite certified also by the results of my experimental cultivations of the plantlets in the laboratory.
