抄録
In Isikawa Prefecture there are nine hot springs - Wakura, Yuwaku, Tyugu, Iwama, Awazu, Seryo, Katayamazu, Yamasiro and Yamanaka. The writer made a collection tour of thermal algae of these hot springs (excepting Iwama) in July 1940. Most of them, however, were not good for the purpose of studying thermal organisms. Some thermal plants were found only in the hot waters of Wakura, Tyugu, Katayamazu and Yamasiro. The most abundant development of thermal vegetation was observed at Tyugu Spa, which is located in the valley of Mt. Hakusan, a dormant volcano. In the hot springs of Wakura, Katayamazu and Yamasiro, only a few species of algae were growing. From these four hot springs 16 species (and variety) were identified in all, including 12 Cyanophyceae, 3 Chlorophyceae and I Euglena. the total temperature range of algal growth in the present investigation was form 33.1℃ to 60℃. In water of the temperature 60℃ at Tyugu, Synechococcus elongatus v. amphigranulatus was growing. One species of Chlorophyceae, Oocystis crassa, is newly added to the Japanese thermal flora.
