94 



HAROLD C. BINGHAM 



Table 4, however, shows that this was not the case. The total 

 average in seconds of time for o 28+ — o 7+ was 11. This time 

 was increased for o 28+ — o 12+ to 16, and for o 28+ — 15+ 

 to 20 seconds. 



TABLE 4 

 Average Time for Choosing 



It might be urged that this time average changed during the 

 course of the experiments on account of the physical condition 

 of the chicks. I do not believe this was the cause. Consider 

 the record made by No. 21. This chick was one of the few which 

 was turned out of doors, where its physical condition improved. 

 That it was not weak at the conclusion of the work on size 

 discrimination is suggested by the fact that it was put through 

 nearly 1500 subsequent tests on form vision. This chick, as 

 shown in table 3, made perfect records in o 28+ — o 15+ dis- 

 crimination. Its time, according to table 4, averaged six seconds 

 during the o 28+ — o 7+ tests, only two seconds in the 28+— 

 o 12+ test, and nine seconds in the o 28+ — o 15+ tests. Evi- 

 dently the chick was slower in the o 28+ — o 7+ tests where 

 it was learning, its time was not increased when the variable 

 was increased to © 12+ because the discrimination was still 

 easy, but the time was increased when the more difficult dis- 

 crimination, o 28+ — o 15+, was required. 



The detailed . behavior of the birds, furthermore, tends more 

 firmly to establish the explanation offered. To illustrate how 

 the behavior differed under the conditions of easy and difficult 

 discrimination, two test sheets are presented. 



