?2 JOSEPH U. Y ARE ROUGH 



responses for Group XIII are given in Table XIV. In the test 

 series only one term of the pair to be associated was presented. 

 These trials would, therefore, not be added to the regular train- 

 ing series in order to secure the number of trials necessary to 



TABLE XIV 



Rat Training Trials Test Trials % on Last 100 



53 J 40 60 90 



54 120 50 92.5 



55 140 60 94 



56 120 50 91 



Average 130 55 91.8 



make the association. Their effect would really be expected to 

 hinder the rate of learning, since each time they took the place 

 of a regular day's work, thus making a break in the regular 

 training series. Since each animal completed his work on the test 

 series, the percentage of right response on the last 100 trials, pre- 

 sented in the last column on the table, includes four series (40) 

 of test trials and three (60) of trainnig trials. It was planned 

 to use only the test trials as a basis for this percentage, but since 

 each animal had held a percentage of 90 or above for a period 

 of seven days we were satisfied that the transfer of response 

 was completely made. 



From Graph 13 in Fig. 8 the rate at which the association was 

 made can easily be observed. The values in this curve represent 

 the percentages of correct response in the test trials given at the 

 end of the first 40 trials and following each series of 20 trials 

 thereafter. The test series was not introduced in these groups 

 until after the first 40 trials, because it was assumed that not 

 until after then would the transfer of response be sufficiently 

 made to make it worth while to interrupt the regular training 

 series. Since the correct response in the 30 per cent of trials in 

 which no stimulus was given had become thorougly learned in 

 the previous training, mistakes in these trials seldom occurred. 

 Consequently, the percentage records of this group may be ex- 

 pected to begin at 30 and increase to 90 and above as the motor 

 response is transferred to the auditory stimulus. Since the test 



