SIZE AND FORM PERCEPTION 



109 



made as a means of getting a discrimination between the later 

 forms. The size of the circle was gradually decreased from 

 o 63+ to o 38+ at which point the tabulation begins. About 400 

 preceding tests were necessary to bring the bird to the point 

 in its training at which the records of the table commence. 



Table 9 shows that the chick was able to acquire the circle- 

 triangle habit. The plan of controlling the qualities other than 

 form was carried out as heretofore explained. After No. 21 

 had acquired the o 28+ — a 28+ reaction, the order shown in 

 the table was followed to determine whether or not the bird 



TABLE 9 



Form Perception: O 28+ — A 28+ and O 28+— □ 28+ 



No. 21. Hatched: February 9, 1912. Sex: 9 



