x SOME EXPERIMENTAL RESULTS 217 



(12). Sliding lid. 



1 taught Jack to open a child's toy box, the lid of which 

 slid out in one direction only. 



During three trials he clawed promiscuously. At the fourth 

 he pawed the top half open, but not seeing that he had succeeded 

 lay down dejectedly. I pointed at the top, and he jumped up 

 and finished his work. He repeated this four times, the last 

 three without any delay. The next day he had to be shown 

 twice, and after this he sometimes clawed from the side or at 

 random at first ; but he always got it right in the end. In the 

 fourth trial, for example, he came round, and clawed from the 

 end. In one case he tried to finish the work with his teeth. 



Clearly it would be possible to learn this by random 

 clawing, and I will not undertake to discriminate the 

 factors in Jack's success. Some of the details that I have 

 mentioned, however, show that, by whatever means, he had 

 acquired a pretty clear appreciation of what was to be 

 done ; that is to say, that the lid had to be pulled, and 

 pulled in a particular direction. My cat wholly failed in 

 this trick because he sat at the end where the meat was 

 put in, i.e. 9 the blind end of the box ; and persistently 

 scratched in that direction. Teufel, on the other hand, 

 learnt the trick in almost the same way as Jack. He is 

 described as watching anxiously during four trials. At 

 the fifth he scraped the lid, slightly opened it, and then 

 was helped. He did not fail again that night or the next, 

 but required a hint once on the third night. 



(13). Pushing of door. 



After Jack had learnt to pull the string, I put the card 

 with the meat on a high shelf, and tied the string to a 

 tack stuck into the top of a cupboard door, near by. The 

 door swung open so as to bring the tack near to the shelf. 

 When pushed away from that position, it would pull the 

 string, and with it the card and food, down to the floor. 

 Jack never showed any appreciation of the mechanism of 

 this arrangement, for after he had learnt to push at the 

 door, he frequently came to the wrong side. I must 

 admit, however, that by pushing hard enough on the 

 wrong side, he caused the door to rebound, and so several 

 times obtained his desire. 



