460 



LIGHT AND LIFE 



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Blinks effect 





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Fig. II. The action spectra for chromatic transients and for enhancement are 

 identical in Chlorella. Lower: The transient as percentage of the steady rate in 

 clianging from 700 ni/x to X. L'pper: Tlie enhancement of pliotosynlhesis by 

 700 n\/x light caused by adding wavelength \. Each wavelength, \, was adjusted 

 in intensity to give a rate equal to that from 700 m/x alone. (From 48). 



are involved. The enhancement may be looked at in two ways. 

 Traditionally the effects of short wavelengths on the enhancement 

 of photosynthesis by light of about 700 m/x has been measured. The 

 experiment can be performed in tlie reverse way. Tlie enhancement 

 of pliotosyn thesis at 650 ni/x may be studied by adding various wave- 

 lengths in the 700 ni/x region. 



The enhancement spectra for the two pigments may also be de- 

 termined by measining the action spectrum of photosynthesis witli 

 a backgroiMid light of about 650 ni/i. and again witli a 700 nifi back- 

 groinid. The cinvc with the 650 ni/x backgroinul is enhanced in the 

 700 ni/i, region, and the ciuve with the 700 ni/A background is enhanced 



