H.5' 



162.' 



ZL9' 



/o 



JO 40 



- m/nutes 



JO 



60 



20 

 77me 



Fig. 2. The course of dark adaptation at three different temperatures. The 

 points are the individual measurements of the reaction time of the five animals 

 indicated in the legend. The curves are those of a bimolecular reaction at the 

 different temperatures. Their velocity coefl&cients are given in the text. 



555 



