258 Studies in Animal Behavior 



teeth until it came undone. The mechanism of the 

 thing, how the hook stood in the way of opening 

 the door, she could not understand, simple as it was. 



When a button was substituted for the hook her 

 mode of attack was much the same; and her prog- 

 ress, such as she made in the course of thirty trials, 

 was after the same slow method. She never per- 

 ceived that when the button was turned in one di- 

 rection it left the door free to come open, and that 

 it prevented the door from coming open when it 

 was in another position. She bit and worried away 

 at the button, and pulled at the door until she got 

 it open and got her food. The idea of the thing 

 never got into her head. 



When both the hook and the button were used 

 Lizzie had a very hard time to get her food. Oc- 

 casionally after much varied and fruitless effort she 

 would succeed. If she got the button turned right 

 she would usually turn it the wrong way before she 

 undid the hook. The experiments would probably 

 have discouraged her observer had they not usually 

 wearied their subject before she met with success. 

 There was little hope that she would be able to 

 solve more complex problems. 



A peanut that was hung below her at the end of 

 a cord she obtained by pulling up the cord, hand 

 over hand, the very first time she saw it. I tried to 

 teach her to use a stick to pull in food with, as 

 monkeys have sometimes been described as doing, 

 but met with no success. Placing a bit of food out- 



