SIZE AND FORM PERCEPTION 



95 



TEST SHEET 1 



Title of investigation, Size: O 28h O 7+ 



Experimented on, 21 



Harvard Psychological Laboratory, February 28, 1912 



Record Sheet, 1. Series, 6 



10-0-3.2 



Test sheet i shows that No. 21 lost no time on entering the 

 discrimination chamber, but went directly in every case to the 

 correct stimulus where it entered the electric compartment and 

 escaped to the nest box. Its final record in this series was 10 

 correct and no wrong choices, with an average time of 3.2 seconds. 

 Test sheet 2 shows a different condition. No. 16 was discrim- 

 inating between 28+ and o 12+. In the first test the chick 

 was quiet for a long while on entering the discrimination box; 

 then it went to the wrong side where it stopped momentarily 

 about two-thirds of the distance between the back of the dis- 

 crimination box and the beginning of the electric wires. It 

 then turned to the left, went close to the left electric compart- 

 ment, hesitated, and entered only to turn to the right and come 

 out. After looking closely again at the wrong (right hand) 

 stimulus it turned back to the right (left hand) compartment 

 and escaped. The behavior was somewhat similar in the second 

 test except that in turning away from the wrong stimulus which 



