LOCALIZATION OF SOUND IN THE WHITE RAT 311 



sound to the two ears. Further tests must be made before 

 this is established beyond question. 



5. In control tests, the rats were not only unable to localize 

 pure tones from tuning forks, but they absolutely ignored them. 

 The same behavior was manifested toward klangs as sounded 

 on an organ pipe. 



6. A noise of 256 d. v. predominant pitch was localized while 

 a tone of the same pitch was ignored. This has a bearing upon 

 the problem of sensitivity to noise with insensitivity to tone, 

 and with Prof. Hunter's work, it may point to separate bases 

 for the perception of noise and tone. 



7. There is evidence to show that if a rat is trained on an 

 interrupted noise, it is disturbed in its accuracy of response 

 by the substitution of a continuous noise. It is impossible to 

 say at present whether the difference is intrinsic or not. 



8. The present localizing-association was retained practically 

 unimpaired for 40 days during which there was no training. 



