STUDIES ON THE CHLOROPHYLLS AND PHOTOSYNTHESIS OF THERMAL ALGAE FROM YELLOWSTONE NATIONAL PARK, CALIFORNIA, AND NEVADA

1. Myxophyceae normally growing at 65°C. evolved oxygen upon irradiation and showed evidence of retaining the power to carry on the process of photosynthesis at 20°C. This indicates that extra thermal energy is not essential for photosynthesis at least over a short period of time. 2. Chlorophyll a and b found in several species of Myxophyceae growing in waters ranging in temperature from 37–72°C. are essentially the same as found in plants growing all over the world. Certain standard chemical tests and spectroscopic examination of the chlorophylls were used as the criteria for these comparisons. The ratio of chlorophyll a to b often varied considerably but in general chlorophyll a showed an increase over the percentage found in most plants. 3. Green algae (Chlorella sp.?) were the only forms found at The Geysers, California. The temperature of the waters from which collections were made varied from 49–66°C. 4. Collections from Beowawe, Nevada were from waters ranging from 60–71°C. The algae belonged to the Myxophyceae and the species were like some of those found in Yellowstone National Park. 5. In some of the calcareous regions of Yellowstone National Park spectroscopic study of the chlorophylls revealed an unidentified absorption band at 548 mµ.