LOCALIZATION OF SOUND IN THE WHITE RAT 



295 



approximately 2 inches wide with the exception of the corner 

 ones which were from 3 to 4 inches wide. The stimulus board, 

 2-1/2 inches away from the main box, was fastened with wooden 

 pegs to the table. This was done to prevent, as far as possible, 

 the vibrations from passing through the wood between the 

 point of sounding the stimulus and the point where the rat 

 was standing. An opaque screen containing peep holes was 

 erected about the apparatus in order to conceal the experi- 



Figure 2. Entire apparatus in perspective, a, main apparatus box; b, the 

 stimulus board; c, the table; d, two sides of the screen behind which 

 the experimenter stood. 



menter from the view of the rats. Measurements of the appar- 

 atus are as follows: 



Minimal width of box 22 in. 



Length of sides 9-9 1/2 in. 



Height of sides (inner) 7 7/8 in. 



Distance of stimulus board from box 2 1/2 in. 



