SIZE AND FORM PERCEPTION 



105 



feet and beg to be taken up. If it were allowed to perch itself 

 on my arm it would sit there as long as I was quiet, contentedly 

 preening its feathers and occasionally giving a short "hovering 

 twitter." 



From these facts, I am led to conclude that the chick 

 really "enjoyed" the experiments. 



Table 7 shows the results of my first study of form with No. 

 21. The chick was trained to go to the triangle and to reject 

 the circle or square. While none of the results here recorded 

 are clear cut, there is strong evidence that the chick was dis- 

 criminating between the two stimuli. This experiment was 

 hurried lest the chick should not remain in good physical con- 

 dition, but at its conclusion the bird was in excellent health 

 so the work was repeated with much more thoroughness. 



No. 21. 



TABLE 7 



Form Perception 



Hatched: February 9, 1912. 



Sex: 9 



The last two series (24 and 25) of table 7 were introduced as 

 control tests. The circle was larger than the triangle, hence it 

 afforded an opportunity to see if the chick would react to form 

 difference, after this training, rather than size difference. Appar- 

 ently it was demanding too much of the chick, for No. 21 be- 



