THE DELAYED REACTION IN CATS 97 



his way, while in II the reaction was half completed. Jim was 

 given 20 trials all of which were correct. Bobby was given 

 60 trials with 57 correct. The reader will notice that the cats 

 have still met no difficulty. 



Delay IV. — Bobby was given 80 trials of which 66, or 82%, 

 were correct. Jim received 130 trials, 107 of which were cor- 

 rect, making also 82%. Here the first difficulty of bridging 

 over a period of delay appears. The door of the release box and 

 the cutting off of the stimulus were operated simultaneously and 

 without reference to where the cat was or what it was doing. 

 Thus the animal was forced to initiate the reaction and perhaps 

 make a choice of compartments, in the absence of the stimulus. 

 The data show that Jim took much longer to master this delay 

 than did Bobby, although he had held a higher percentage on 

 fewer trials in the three preceding delays. The fact that Jim 

 had received 100 trials less than Bobby in these preceding 

 delays can be offered as explanation of his need of 60 more trials 

 here. It seems natural that had he not been advanced so rapidly 

 from one delay to another he would have been better prepared 

 for this new delay, and, being better prepared, would have 

 bridged over it much more quickly. 



Two seconds delay. — At this point in the experiments a metro- 

 nome was placed in an adjacent room to mark the period of delay 

 in seconds. At this distance its sounds could be easily heard 

 by the experimenter, yet they were not thought to be strong 

 enough to distract the attention of the animals. 



Bobby was given 130 trials with 106, or 81% correct; while 

 Jim was given 200 trials, 143, or 71% of which were correct. 

 Of the last 40% of Bobbie's trials, 34, or 85% were correct; of 

 the last 40% of Jim's trials, 32, or 80% were correct. The 

 data do not show that the reactions were poor at the beginning 

 of the delay and grew better with successive trials, but rather 

 show an irregularity throughout. Bobby, e.g., was perfect on 

 the first 10 trials, while after having received 70 trials she made 

 only 50% on 10 trials. Again, Jim, after 160 trials, made only 

 30% on 10 trials, yet on the 10 just preceding, he made 90% 

 and 80% on the 10 immediately following. 



Four seconds delay. — In the four seconds delay experiment, 

 180 trials were given Bobby with 141 correct, and 150 given 

 Jim with 118 correct. Each made 78% correct. Jim's last 30 



