208 



MIND IN EVOLUTION 



CHAP. 



link and into the hole. The chain was too tight for 

 Jack to get at it with his teeth, and the only resource was 

 to pull out the skewer. 



During five trials Jack 1 bit and pulled indiscriminately at 

 lever, chain, and skewer. At the sixth trial he pulled skewer out 

 awkwardly. 2 



At the seventh he pulled it half out with an effort, and then 

 gave up, returning after an interval, and pulling it out. There 

 was then an interval, after which his record is as follows : 



8. Scratches long time at chain ; does not try to pull skewer out 

 with teeth. 



9. Half pulls out with teeth ; tries to scratch out rest of the 



BOX ARRANGED WITH LOOP. 



/, lever ; A, loop ; g, gimlet. 



BOX ARRANGED WITH SPIKE. 



/, lever ; c, chain ; s, spike. 



way and to push his nose through the door. Shown. Time 

 3 minutes. 



10. Half pulls skewer, gets it out at last ; declines to open for 

 some time, at last opens. 



11. Knocked skewer further in with nose, scrabbled, barked, 

 gave up. I put skewer so as to project beyond bar ; he opened. 

 Time, little over I minute. 



12. Pulls it out and opens with very little scrabbling. 



13. Reluctant, little scrabbling, opens. Time 30". 



14. Pulling at skewer nearly all time j skewer-head in beyond 

 bolt. 35". 



15. Does not try to bite skewer for long time, but pushes at 

 lever and chain. I pull skewer out beyond bolt, thinking he 



1 In the first trial I had used a string, which he managed to get off (he 

 had had a previous experiment of this kind which failed owing to defective 

 mechanism). I then substituted the chain. At the fourth trial he took 

 the skewer in his teeth as I was pulling it out. 



2 I left it projecting further, so that it was more easily grasped. 



