VISUAL PERCEPTION OF THE CHICK 



99 



Furthermore, Coburn's 9-6 relative reaction tests had been 

 closely approximated in training when the 9-5 combination had 

 been employed. For this reason his additional comment again 

 seems questionable: "The results for crow No. 1 with the 6 

 centimeter circle when displayed with the 4 centimeter and the 

 9 centimeter circles, on August 26th and 27th were almost as 

 decisive." While there had been no specific training on the 9-6 

 combination as such, there had been, aside from its close ap- 



TABLE 17 



Reactions to Relative Flicker Difference 



Chick 27 9 



proximation, frequent changes from one relation to another which 

 might have had the effect of a "relative difference preparation." 

 It seems probable that Coburn's conclusions are correct but 

 they are hardly justified on the basis of his experimental 

 method alone. 



My results on the reactions of the chick to relative rates of 

 flicker are less positive than the results from the size tests. 

 The method in the flicker study was slightly changed. As 

 table 17 indicates, the chick's training was continued daily 

 while two relativity tests were inserted in each series consisting 

 both of faster and slower rates of flashing. The first day the 

 chick chose the slower rate regularly in all training tests and in 

 both of the relative flicker tests. On the second and third days 



