STIMULI DURING DELAYED REACTION IN DOGS 



275 



The rhythm for these trials was very irregular, being selected 



"■forehand and only varied by keeping the dog at a compartment 



he had gone to it correctly. Then the regular schedule 



,,cts resumed. This method seemed preferable to that of keeping 



to the fixed schedule strictly, as it gave the dog extra practise on 



the compartments to which his cues seemed to be weakened. 



Fifteen Seconds Delay. C2 — The fifteen seconds delay type 

 of the experiments given under condition "C2" extended over 

 the j^riod between January 17th, 1914 and February 12th, 

 1914. In all there were sixty-seven trials, and of these forty- 

 four, or 66-2/3%, were successful reactions. The last twenty - 

 tWjO trials showed much improvement and gave 85% of them 

 as correct reactions. The highest record reached on any indi- 

 vidual day were those on February 6th and February 12th, 

 1914, when nine out of ten and twelve out of fourteen trials 

 were correct. The results of the earlier series were lower and 

 showed a decreased learning power instead of an increased one 

 as a result of training. This decrease was due to the apparent 

 failing, o r the cues to No. 3 compartment. This failing was 

 noted in. til the types of experiments going on at this time, and 

 a specjUl check series of twenty trials on No. 3 compartment 

 was $i sn to restore these cues. After regaining the cues, the 

 records given above as the highest obtained, were the results. 

 The reactions to the other two compartments became more 

 aca 1 ' :*;e, due to the training, as the records show, for while at 

 first ne errors on No. 3 were only 40% of the total number of 

 errors, they were 71% at the end, just before the check experi- 

 ments were given, and the total number of errors increased 

 onl) 7%. As the increase of errors on No. 3 was 74%, the 

 differ, ace can only mean that there was a strong decrease in 

 the ~ors on the other two compartments. The summarized 

 resm'ts for "Fifteen Seconds Delay"— "C2," are as follows: 



d-/17/14 17 trials 10 correct 57% Errors equal on No. 1, 



No. 2, and No. 3. 



Falling off on No. 3. 



6 of the errors on No. 3. 



Last five correct — Error 

 on No. 3. 



Last five correct — Errors 

 on No. 3. 



