SIMILARITIES BETWEEN DAILY FLUCTUATIONS IN BACKGROUND RADIATION AND O2-CONSUMPTION IN THE LIVING ORGANISM ,

1. O2-consumption of potatoes was recorded continuously through the fourmonth period, February-May, 1956.2. There were daily fluctuations in rate which, even using 3 x 7-hour moving means, displayed a mean amplitude of about 14%.3. Five independent respirometer-recording systems yielded mean daily cycles for the four-month period ranging in amplitude from 4.8 to 10.0% with a mean of 8.2%.4. The mean cycles were of two forms, one essentially 180° out of phase with the other.5. Solar-day and lunar-day mean fluctuations in background radiation were also determined for the period of the investigation.6. A small but very highly significant correlation existed between the fluctuations in amplitude of the daily cycles in radiation on day n-1 and amplitude of the daily fluctuations in O2-consumption in the potato on day n.