346 



LIGHT AND LIFE 



type or the mutant type (which does not contain the carotenoid) of 

 Rhodopseudomonas is used (3) . The signal is characterized by various 

 physical methods such as the signal growth rate, decay rate, band 

 width, etc. 



Apparent Spectral Efficiency 



Finally, an apparent action spectrum for the production of these 

 signals (63) , both in the green plant material (chloroplasts) (Fig. 25) 



20 



15 



o 

 iij 



X 



< 

 z 

 o 

 to 



I \ 



-LEFT ORDINATE 

 -- RIGHT ORDINATE 



400 



500 



10 



08 



106 '- 



z 



UJ 



o 



ACTION 



0.4 



02 



00 

 800 



< 

 o 



a. 

 o 



600 700 



WAVELENGTH-mp 



I'ig. 2"). Absorption and action spectra of cliloroplasts (Sogo) I„ = 10' 

 quanta/sec. Band width^lOO A. 



and in the red bacteria (Fig. 26) , is shown. This apparent action 

 spectrum is a very curious one and has a peak at about 7200 A, with 

 a minimum approximately where the peak of absorption of the 

 chlorophyll in the living organism is, namely, at 6800 A (59) . A 

 similar behavior for the apparent action spectrum of the signal pro- 



600 



1.0 



0.8 



06 



0.4 



0.2 



o 



z 

 < 



CD 



tr. 

 o 

 (ft 



OQ 



900 



1000 



700 800 



WAVE LENGTH -mp 



Fig. 2(>. Absorption spectnnn (.Sbil)ata. Benson) and action spectrum 

 llhoduslnriUuiii nihnnn. I„ = .') X 10" quanta/sec. Band widtb = 



(Sogo) of 

 66 A. 



