VISUAL PERCEPTION OF THE CHICK 



25 



chamber, 26 by 51 by 22. Leading from A to ^ Is an entrance, 

 /, 8 by 10. The floor of B, Hke that oi A, is carpeted with wet 

 felt. The tray of either compartment can be easily removed 

 and cleaned. (3) W and W are electric boxes separated from 

 each other by the partition D. On the floors of W and W is a 

 slab of slate carrying electric wires for punishment. By means 

 of the interposed sides, 0, the electric compartments are 



Fig. 4 

 Experiment box as seen from above. 

 Behavior, vol. 3, p. 69. 



Reprinted from Journal Animal 



set back 14 cm. from the stim.ulus shifter. The floor of this 

 extended portion drops down about 10 cm. below that of W-W . 

 The middle presses closely against the shifter so that the 

 exposed stimuli are sharply separated from each other. On the 

 end of D-0 is glued a piece of piano felt, P, which rubs snugly 

 against the shifter. (4) N and N' are nest boxes, 40^ by 22 

 by 22. Each nest box is covered by a tightly fitting lid, which is 



