LOCALIZATION OF SOUND IN THE WHITE RAT 309 



determine the relative accuracy of the rat during the standard 

 reactions in regard to the three bodily positions, namely, when 

 headed towards the operator, when headed away and when 

 sideways. Many tables and curves were constructed, but no 

 conclusions bearing upon the ratio in question were reached. (It 



If da.y: 



Figure 3. Average accuracies per day of rats 21, 22 and 23 showing, a, accuracy 



with head pointed away from section tapped, b, accuracy with head pointed 



toward section tapped, and, c, accuracy when rat was sideways to the 



point of stimulation. A storm occurred at x. 



is well in this connection to bear in mind the writer's comments 

 upon general method made above, pp. 299.) Figure 3 brings 

 out the not unexpected fact that the rat's greatest accuracy 

 came when it was oriented toward the source of stimulation. 

 When the animal was oriented sideways to the stimulus, it 

 reacted with the next degree of perfection. The least accurate 

 responses occurred when the animal was headed away from 

 the stimulus. 



C. Tests on Retention — In order to discover the degree of 

 permanency in the localization-association, memory tests were 

 made upon the six rats after various intervals in which there 

 was no training. Rats No. 4 and 6 were tested first after an 

 interval of 40 days and then after an interval of 38 days. In 

 each case there was essentially perfect retention. (See table VII.) 



TABLE VII. 



Rats 4 6 



Dec. 18 2 1/2 1 1/2 



Jan. 29 4 4/8 1 1/8 



Jan. 30 3 6/8 3/8 



Mar. 8 2 1/2 2 



