196 MIND IN EVOLUTION CHAP. 



(4). Pull-bolt. 



The same and similar boxes were fastened by a loose 

 bolt which could be drawn right out. I call this the 

 pull-bolt. 



I first showed this box to Jack placed on a chair in such a 

 way that the bolt being drawn the lid would fall. He pulled 

 the bolt out at once with his teeth. This was not extraordinary 

 cleverness, but rather a c< false analogy " from the lever experi- 

 ment. He had been accustomed to seize the lever in his mouth 

 and pull, and he now treated the bolt in the same way. To 

 determine how far he could discriminate the two things, I gave 

 him the two boxes alternately, and found that he got on very 

 well as long as one box was on the floor and the other on the 

 chair so arranged that the bolt was end on to him as he approached 

 it. But next day I placed both boxes on the floor, and much 

 confusion resulted. Four times Jack pulled the bolt as though it 

 were the lever, at right angles, and had to be shown. The fifth 

 time he got it roughly out, helping himself at the end with his 

 paw. 



I subjoin the rest of his " record " under this head. 



Same afternoon (this from imperfect notes jotted after series 

 was over) he had to be shown the lever once, and was then suc- 

 cessful. (His experience with the bolt would of course put him 

 off the lever.) Then was thrice shown bolt. Then succeeded 

 twice. 



Next day the bolt and bar are put on the same box, which 

 is now slightly tilted so that it is necessary to paw bar (after 

 the bolt is drawn out) to open it. 



1. Pulls out bolt, but puzzled because door does not open. 

 Shown. 



2. Scrabbles and pulls more or less in right direction, but has 

 to be shown and also have door opened for him. 



3. Gets bolt out, and opens door half by accident. 



4. Pulls out bolt very awkwardly, and after delay, opens door. 



1 now give him the bar alone. 



i. He takes it in his teeth, but has his paw against the door, 

 and gets violent. I have to set the box to rights and give it him 

 again, when he opens it. 



2 and 3. Opens bar upwards. 



We return again to bolt, which he pulls out better, but he 

 scrabbles so hard at door that it breaks. 



Two or three days after, pulls out bolt and opens box three 

 times, though coming up from off side and from behind. Also 

 twice pulls out bolt by string attached to it. 



