TRANSFER OF RESPONSE IN THE WHITE RAT 25 



stated above, the responses became so rapid, where no 

 punishment was given for a wrong choice, that one would be 

 led to think that the sound was wholly ignored. Further, if 

 the rats were negative, the omission of the sounds should 

 show an increase in percentage of correct choices. Let us 

 notice the last 100 trials with the sound stimulus in groups 

 III and IV, and the five control series or 100 trials where the 

 sound was omitted. The last 100 trials with the sound in 

 Group III average 68, 66, 66, 67, 67. The 100 trials with- 

 out the sound average 69, 69, 69, 64, 64. A slight advan- 

 tage is shown for those without the sound. In group IV the 

 last 100 trials with sound average 64, 68, 62, 66, 6S. The 

 100 trials without sound average 67, 68, 63, 68, 63. No 

 advantage is shown for either. 



Although no convincing evidence can be found in the records 

 that the rats did not learn because they were negative to the 

 sound presented, yet to give the matter a further trial a 

 less metallic sound was sought, if that should prove to be the 

 difficulty in the way of learning. For that reason a telephone 

 receiver was substituted for the electric buzzer used with 

 groups III and IV. A duller, more wooden sound was thus 

 secured. No one of the six rats in Group V gave any 

 evidence of learning the response after 800 trials. Neither 

 the records nor the general behavior showed that the rats 

 were negative to the sound. Groups VI and VII were 

 trained with the same sound as Group V but were given 

 pain as a punishment for wrong choice, but 1200 trials for 

 four of them brought no convincing results. 



As a last resort a short test with one rat was tried with a 

 sound to which from general behavior we had every evidence 

 for believing the rats to be positive. This sound was the 

 dropping of sunflower seed in a dish. Any one who has 

 handled rats knows that such a sound will cause in a hungry 

 rat a very active hunting for the source of the sound. The 

 method of procedure was as follows: One experimenter 

 was placed behind a screen at the end of the box marked 

 MN in figure I. A dish of sunflower seed was placed at the 

 position of each of the sounders, S and S'. The other ex- 

 perimenter took the regular position in front of the box. 

 When the animal was placed in the entrance alley (EA) the 



