. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. RHYTHM OF LUMINESCENCE 449. 10 TIME -HOURS FIGURE 8. The effect of light perturbations (1400 foot-candles for 3 hours) given at dif- ferent times during the cycle, upon the phase of the endogenous rhythm. Cells which had been kept under LD conditions were placed in the dark at zero time on the graph, which was the end of a 12-hour light period. The times at which the maxima in luminescence occurred in the control, which remained in the dark all the while, are indicated by vertical lines. In the experimentals, a triangular sy
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. RHYTHM OF LUMINESCENCE 449. 10 TIME -HOURS FIGURE 8. The effect of light perturbations (1400 foot-candles for 3 hours) given at dif- ferent times during the cycle, upon the phase of the endogenous rhythm. Cells which had been kept under LD conditions were placed in the dark at zero time on the graph, which was the end of a 12-hour light period. The times at which the maxima in luminescence occurred in the control, which remained in the dark all the while, are indicated by vertical lines. In the experimentals, a triangular symbol shows a time at which a maximum in luminescence occurred, and thus represents phase. The experiments were carried out in a way similar to those illustrated in Figure 6. Each horizontal line represents a different experiment. For ex- ample, the line at 11 hours on the ordinate was an experiment in which a maximum in luminescence occurred at 7 hours. A light perturbation was begun at 11 hours and terminated at 14 hours. Maxima in luminescence occurred subsequently at 29M> hours and 52% hours. The other experiments are represented in a similar way. The relationship between the time in the cycle at which the light perturbation was administered and the number of hours by which the phase was changed may be better visualized by rotating the figure by 90°. chamber at the end of a light period. At regular time intervals thereafter, some of the cells were removed and exposed for three hours to light at an intensity of 1400 foot-candles, and then returned to darkness. Times at which exposures to light were made were selected so that the experiment served to scan somewhat more than a full 24-hour cycle. A control received no exposure to light, and the times at which maxima in luminescence occurred in this control are indicated by the vertical lines in Figure 8. The results of the experiments are summarized in Figure 8. First of all, it may be noted that the new phase, following a
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
