SECTION FOUR 



FEATURES BEARING ON TRANSFER 



A. Positive 



(1) Light to Sound, — Two groups were trained with the 

 light stimulus and transferred to sound. Group I was 

 transferred directly from the light to the sound when once 

 the response to the light had been learned. With Group II 

 each animal was given ten series or two hundred trials with 

 the light and sound stimulus presented simultaneously, 

 after the response to the light had been learned, and then 

 transferred to the sound. 



The curves given on page 20 show the general results. 

 These curves show the learning of the response to the light 

 stimulus, but they also show the record for the control 

 series in each case, the record for any simultaneous light 

 and sound stimuli, and the record for the sound stimulus 

 alone which was substituted for the light stimulus. 



The immediate result of the transfer was that the two 

 groups dropped in efficiency 36 per cent and 26 per cent 

 respectively, or down to that degree of efficiency which 

 can be. accounted for by chance or position habits. Three 

 of Group I were given 25 series or 500 trials with the sound 

 alone and at that time showed an average efficiency of 72 

 per cent whereas they started the sound with an average 

 of 67 per cent. The other two of this group were given 

 11 series or 220 trials with the sound, and ended with an 

 average of 70 per cent, whereas they started the sound 

 with an average of 55 per cent. All six members of Group 

 II were given 20 series or 400 trials with the sound alone 

 after the series with sound and light simultaneously and 

 ended the 20 series with an efficiency of 67 per cent whereas 

 they began the sound alone with an average of 73 per cent. 

 As stated above a study of the records shows that the 

 animals all began to depend almost wholly upon alterna- 

 tion when the sound was substituted for the light, although 



