338 



Profs. Percy Frankland and Marshall Ward. 



longer than I could measure next morning. The device was success- 

 ful, as the curve shows. 



Then, having measured both cultures at 9 A.M. next morning, I 

 placed the one hitherto between red glasses between the blue glasses, 

 and vice versa, to see if, during the second day's exposure, there 

 would be any appreciable changes in the curves. The results are 

 given in the accompanying table and curves (Curves 30 and 31) : 



As before, the germination in the blue was markedly retarded, as 

 shown by the measurements up to 11 P.M. Both grew much more 

 slowly during the night (when the temperature fell to 7 C.) than 

 would have been the case at 12 14 C. (see preceding curve) ; and 

 both began to grow quickly after 9 A.M., in accordance with the rapid 

 rise of temperature from 9 to 11 A.M. 



But the most interesting result is shown in the growth from 

 11 A.M. onwards, when the light began to increase in intensity, for 

 the culture hitherto under blue glass, but now under red, began to 

 grow much more rapidly, so that its curve offered to cross that of the 

 now retarded culture previously in the red and now in the blue. 



It seemed almost impossible to deny that this must be proof of 

 the light-action. 



Spores were sown at 10 A.M. in water, with one drop of broth per 



