x SOME EXPERIMENTAL RESULTS 207 



learning. There was only one occasion after her first 

 success in which she so far forgot herself as to try the 

 lever first. 



(70 (Loop). 



As already mentioned, Jack's box had an iron lever 

 projecting from the lid by which it was opened. I drove 

 a gimlet into the side of the box parallel with the lever, 

 and placed a brass loop over it and the lever. As I 

 placed the box for Jack, the loop had to be pushed up in 

 order to open the box. Jack learnt this after being shown 

 twice. 



During the first two trials Jack " scrabbled " a good deal, once 

 or twice nearly knocking the loop up with his nose in the course 

 of his random movements. The loop was twice pulled off, and 

 he was left to open the box. The third time he knocked up the 

 loop with his nose, and with some difficulty opened the box. He 

 did not fail again, though for three or four trials there was some 

 useless preliminary scrabbling. 1 Sometimes the loop stuck a little, 

 and he would then push hard and repeatedly. Next day, there 

 was a little scrabbling at the first trial, but no failure. 



There may have been an element of accident in the 

 first success. It was within the scope of a random move- 

 ment. The dog seemed quite clear in this instance as to 

 what had to be done. The persistence and gradual dying 

 away of useless scrabbling is noteworthy. 



The cat did this trick at sight. 



No doubt attracted by the novelty of the loop (which for his 

 benefit was put sideways), he began clawing at it at once, and in 

 about 90 seconds got it off and opened the box. He repeated 

 this eight times, but showed a tendency to claw at the gimlet 

 (also a novelty) before the lever. The total times varied from 

 60" to 1 5". The next night he refused to try, but the next he 

 succeeded, awkwardly, three times. 



This was a clear case of a single random success having 

 a permanent effect. 



(8.) Spike. 



Taking out the gimlet I put a small chain over the 

 lever, and, stretching it tight, stuck a skewer through a 



1 From the seventh to eleventh trials inclusive, his average time for the 

 whole process was under 14*. 



