SUMMARY 



8 9 



darkness on the induction-periods of the successive bubbles 

 (fig. 26). The results afford strong evidence of the partial 



neutralisation of the positive work, brought about by 

 molecular recovery during darkness. In the next chapter 

 I attack the same problem by the independent method of 

 rapid intermittent exposures to light alternating with equal 

 periods of darkness. 



Summary 



The total volume of oxygen given out is proportional 

 to the duration of exposure to continuous light of uniform 

 intensity. 



This quantitative relation does not hold good under 

 interrupted light. The ' uphill ' or positive work done in 

 the light is partially undone during the period of darkness. 



The induction-period is increased with the period of 

 previous darkness, till it reaches a limit. 



