280 



MIND IN EVOLUTION 



CHAP, 



4. Bolt fastened by hook. 



I took the box with the push-back bolt, tied a string to 

 the knob, and, passing it round the box, fastened it by a hook 

 to a nail at the back. The string now held the bolt 

 forward in the staple, so that unless the hook was removed, 

 the bolt could not be pushed back. Jimmy at first failed 

 to find out how to open this box, but one day appeared to 

 learn it, as it were, in a flash. 



A. Diagram showing box with hook fastened to wire netting. 



B. Diagram showing hook fastened to nail at back of box. 



At the first trial, he worked a good deal at the bolt, bit the 

 string a little, and after a time, took the hook off. He then 

 began to work at the bolt, and might have found it all out, but 

 that his attention was suddenly distracted. After this, though he 

 two or three times took the hook off, the action was purposeless, 

 as he would go away again, and perhaps not try the bolt until a 

 minute had passed, or perhaps not at all. Two or three days 

 afterwards, however, I was putting my hand to the hook, mean- 

 ing to take it off without letting him see. Apparently this called 

 his attention to the hook. He at once took it off, and almost 

 immediately, came round the box, pushed back the bolt, and 

 opened it. He repeated this five times, and when the hook was 

 too tight to come off, he would pull the string till it slackened. 

 To baffle him, I now turned the box up so that the hook was 

 underneath. At first, not finding the hook, he pulled at the string 

 and worked at the bolt ; but at length he turned the box over, 

 the hook fell off, and he opened. 



I then further varied the experiment by fastening the hook to 

 the netting of his cage, pulling the box away from it so that the 

 string was taut. After trying the bolt a little, he attacked the 

 hook ; but it was too tight to come off. He then threw the box 

 about, until he turned it into a position in which the bolt fell. 1 

 After another trial, in which he failed to remove the hook, I 



1 He had an amusing struggle to keep the lid up while he got under- 

 neath it. Finally he threw the lid right back. 



