24 HARRY H. WYLIE 



later, yet the main thing to be noticed in the results is that 

 not a single animal out of the 32 trained learned to choose 

 the 'noisy' alley even though some were given as high as 1600 

 trials and even though pain was used as punishment for 

 wrong choice in the case of a number. Also as will appear 

 later in our study of Transfer effects, even those animals 

 which had learned the positive response to the light failed to 

 learn the same response to the sound. A number of explan- 

 ations or reasons may be offered for this. 



First, it may be claimed that the animals could not hear 

 the sound presented. That is disproved, however, by the 

 fact that other animals did learn the negative response to the 

 very same type of sound. 



Second, it may be that the reaction required lay outside 

 the animal's ability to learn. However, eleven animals did 

 learn the same response, when a light stimulus was used, 

 with much smaller number of trials than were given with the 

 sound stimulus. 



Third, perhaps the rats were negative to the types of 

 sound used and so would not learn a positive response to 

 such sounds. The records, however, do not give any con- 

 vincing evidence to support this contention. Since the rats 

 had free opportunity to enter either the 'noisy' or the 'quiet' 

 alleys, if they were negative to the sound, we should expect 

 some evidence of it in the early part of the records. The 

 rats should have made many more than 50% of errors until 

 they had become accustomed to the sound. In Group III the 

 averages for the first 200 trials were 46, 49, 51, 53, 50, 51, 48, 

 54, 49, 56; just about what chance would give in the long run. 

 The records for the other groups show about the same 

 results. No signs appeared in the general behavior of the 

 rats, except in one or two individual cases, that would go to 

 support the contention that they were negative to the sounds 

 presented. Rat number 7 in group III was one of the ex- 

 ceptions. It was, however, an extremely nervous animal 

 and objected to being handled. Its daily record often 

 contains such a statement as the following; " Would not 

 work well today. Seemed frightened." With practically 

 all the animals, however, one could not tell from their gene- 

 ral behavior that they even .heard the sound at all. As 



