LOCALIZATION OF SOUND IN THE WHITE RAT 



307 



time. Results, reckoned in accuracy in respect to the sections 

 tapped by Hunter, are as follows: 



As a rule the rat went to the heavier tapping, as may be seen 

 from the results. 



The question at once arose whether the first tap did not 

 direct the rat's localization. Accordingly, a similar control was 

 installed (X) in which the lighter tapping was begun first, acting 

 as a guiding signal to Hunter. The control was not entirely 

 comparable to control IX, however, for in order to insure the 

 fact that the lesser intensity was perceived, the rat was always 

 allowed to make a decided start towards the lighter tapping 

 before the heavier was begun. In spite of this decided advantage 

 for the lesser intensity, the reaction broke down in accuracy, 

 i. e., they failed to choose the lesser intensity. This shows 

 that the mere giving of the sound first by Hunter in control IX 

 did not determine the response to the heavier tapping. Results 

 reckoned in accuracy in respect to the sections tapped by Barber, 

 are given in Table VI. 



TABLE VI. 



The following reaction is typical of the responses made: 



B' on A' A 4 B C D 13 (H 29.) Interpreted, this means 

 that the rat was in triangle B' (see fig. 1) headed towards the 



lesser intensity when the tapping was begun (B'), went on to 



