SIZE AND FORM PERCEPTION 



103 



TABLE 6 



Form Perception: O 28h — A 28+ 



No. 9. Hatched: December 1, 1911. Sex: 9 



that the chick perceived form. The preference may well have 

 been due to the distribution of light or the unequal stimulation 

 of different parts of the retina. 



As has been earlier stated, the original plan was to test the 

 minimum form difference a chick could perceive. The result of 

 my investigation with No. g convinced me that it was neces- 

 sary first to determine whether or not the chick perceives form. 

 When the study of form perception was begun with group 3, 

 the plan that was explained in the preceding chapter on size 

 was adopted. That is, form, in the beginning, was made only 

 one of other visual factors which were gradually eliminated as 

 the experiment progressed. Only one chick, No. 21, gave any- 

 thing like positive results. This bird, including 22 series on 



