SELIG HECHT 



385 



^C?d? 



SCO 



Wave-length 



600 



•fjfj 



700 



Fig. 5. Relative effectiveness of the spectrum in sensory stimulation. The 

 curve also represents the absorption spectrum of the photosensitive substance 

 of Mya. In the latter case the ordinates represent per cent of absorption by the 

 sensitive substance. 



