I О PHYSIOLOGY OF NUTRITION 



centration and finally merge into one another, so that only the red rays, between 

 A and B, and a part of the green can pass through a concentrated solution or a 

 thick layer; finally, with still further increase in concentration or thickness 



Pig. 5. — Absorption spectra of five different concentrations of chlorophyll a. {After Willstätter 



and Stoll.) 



Fig. 6. — Absorption spectra of five different concentrations of chlorophyll b. (After 

 Willstätter and Stoll.) 



of layer, the green rays are also completely absorbed and only the rays between 

 A and В are transmitted. All objects appear red when seen through a very 

 concentrated solution or a very thick layer. 



