146 J. FRANCK 



Benson : But you can do it in the dark just as fast as in the light. 



Bassham: Why call on a second way when you already have one which 

 works? 



Gaffron : Because nuiii.y other data do not quite fit this rather plausible 

 assumption. I am a biochemist, too. My way of thinking is like yours, and it is 

 only from contact with Prof. Franck that I am learning to distrust this simple 

 way of explaining by analogy. From the biochemical viewpoint, we have here 

 an obvious explanation of how the light can be used very efficiently, but the data 

 of the photochemists unfortunately do not quite jibe with the idea of a primarj^ 

 intermediate hydrogen acceptor which in turn reduces everything else. Dr. 

 Franck chooses to worry about the existent difficulties. Some of us may believe 

 it is unnecessar}' to worry. But the fact remains that there are some reliable data 

 which are difficult to explain unless one assumes that at least one component of the 

 Benson-Calvin cycle sticks very close to the chlorophyll itself. 



