FLUORESCENCE SPECTRA OF PLANTS 



809 



Table 24.11 

 Fluorescence Bands of Chlorophyll in Plants and in Ethereal Solution" 



" On Ilford Infrared Plates. 



* Biermacher (1936). 



•^ cf. table 23. I. 



'' The difference between these values and those in Table 23.IB is attributed by 

 Biermacher to the decrease of the sensitivity of the infrared-sensitive plate in the 

 orange. The values in Table 23. IB are supposed to be the correct ones; they are not 

 used here, to preserve the consistency of Table 24.11. 



bands. The strong shift of peak I is due to self-absorption. French 

 (195/1) found it at 675 m^ in a faintly green, and at 685 m^t in a dark-green 

 leaf. The intensity ratio I: II was 5: 1 in the first, and 1 : 1 in the second, 

 case. 



Vermeulen, Wassink and Reman (1937) gave spectrophotometric 

 curves of the fluorescence of the alga Chlorella (chlorophyll a + 6) and the 

 bacterium Chromatium (bacteriochlorophyll), which are reproduced in 

 figures 24.2 and 24.3. Chlorella shows a peak at 680 m// and only a shoulder 

 at 740 m^i. Duysens (1951) found that, even in light absorbed by chloro- 

 phyll b, Chlorella shows only the fluorescence of chlorophyll a — indicating 

 efficient energy transfer from h to a. 



• Illuminated with Hg lomp 

 with UG2 filter 



o Illuminated with total 

 Hg radiotion 



650 



700 



750 



WAVE LENGTH, m/i 



Fig. 24.2. Fluore.scence spectrum 

 of Chlorella suspension (after Ver- 

 meulen, Wassink and Reman 1937). 



Illuminated with Hg lamp with UG 2 filter 

 Illuminoted with Hg lamp with 

 yellow-green filter 



Illuminated with total Hg rodlation 



./ 



y 



800 750 



800 



850 



900 



950 



WAVE LENGTH, m^ 



Fig. 24.3. Fluorescence spectrum of Chro- 

 matinm suspension (after Vermeulen, Was- 

 sink and Reman 1937). 



