C. STACY FRENCH 



69 



600 650 700 750 



WAVE LENGTH IN MU 

 Fig. 18. Fluorescence spectra of Porphijridium cruentum excited by various inci- 

 dent wavelengtlis. The curves are reduced to their relative sizes for the same 

 number of incident quanta at all wavelengths. (French and Young, 1952.) 



700 750 



600 650 



WAVE LENGTH IN MJU 

 Fig. 19. Estimated contribution of three different pigments to the total fluores- 

 cence of Porphijridium when illuminated by wavelengtli 530 m/^. (French 

 and Young, 1952.) 



