VISUAL PERCEPTION OF THE CHICK 



27 



really a delicate latch narrower than the width of T or E and is 

 released by a slight touch upon T. 



2. Source box 



To provide illumination for the two stimuli simultaneously 

 presented to the chick, the source box represented in figure 6, 



w 



Fig. 5 

 Automatic tripping device of the experiment box. Reprinted from Journal 

 Animal Behavior, vol. 3, p. 70. 



— 1 1 1 of figure 3 , — was used . A complete description of this part 

 of the mechanism appears in Behavior Monographs from which 

 figure 6 is reprinted. 



