THE RHYTHM OF OXIDATIVE PROCESSES 285 



objects when smaller doses are administered, it produced no immediate de- 

 jDression, but radiation irritation i.e. a reverse reaction. I believe that if" the radi- 

 ation dose given to the leaf had been increased then, taking into account the small 

 sensitivity of the developing leaf, we would have obtained an identical effect. 



errera: Would it not be possible to link the rhythmicity in the cell's oxygen 

 tension in the experiments with brain with the heart's rhythin? 



FRANK : Of course. When we worked with living warm-blooded animals naturally 

 the question arose as to whether it would be jDossible to link this rhythm with that 

 of the circulation. It could not be compared to the heart's rhythm, they differ by 

 their frequency, but the question arose whether this rhythm could not be the 

 effect of the play of the vessels, the vessel's contractions. Of course, this question 

 could not have been solved if we had not worked with isolated pieces of the 

 tissues, with isolated liver and other objects, in which there is no circulation. 



BLUMENFELD : Did you study the effect of temperature on the rhythm? 



FRANK : We studied the temperature effects on rhythm, of course not on warm- 

 blooded animals but on simple objects — developing frog eggs, plants and so forth. 

 In the effects of the temperature on the rhythm there are clear-cut regularities. 

 We also studied effects on the oxygen supply. 



