RATE OF LEARNING IN THE CHICK 



117 



The experiments with the first group indicated also that 

 chicks without preliminary training showed a very marked 

 tendency to choose the more brightly illuminated screen. I 

 therefore trained the chicks to escape to the hover box by choos- 

 ing the darker screen. This was done also in order to make the 

 results of my experiments more nearly comparable with those 

 of Yerkes and Dodson, who trained their mice to select the 



TABLE II 



Positions of Darker Screen for Two Preference Series and Twenty- 

 five Training Series 



Subject Date . 



Experiment . 



