PHOTIC REACTIONS OF TADPOLES 



269 



or decrease in the reaction-time. This period is reached in 

 fifty minutes. The condition is shown graphically in figure 8, 

 where the data in table 7 are used, the reaction-time being 

 plotted as the function of time in the dark. The curve also 



TABLE 



Summary table of average reaction-times in seconds for photosensonj recovery in 

 four tadpoles of Rana clamitans 



o 

 a 



<v 



Qj 30 



O.0 



Oz 



Tme mdark- /^ mutes 



Fig. 8 Curve illustrating the process of photosensory recovery. The reac- 

 tion-time (seconds) is plotted on the ordinates as function of time in the dark 

 (minutes) on the abscissa. 



