Figure 1. Oxygen evolution during the LD cycle at 3 different light intensities followed by LL cycles.

1) 100 µmol quanta m⁻² s⁻¹, 2) 75 µmol quanta m⁻² s⁻¹ and 3) 40 µmol quanta m⁻² s⁻¹. White bars indicate the light period, black bars the dark period and grey bars subjective darkness (Each time point N = 4, ±S.D.).