240 THE INTELLIGENCE OF MAMMALS 



ever she made her escape, the cat came to enter the box of 

 her own accord. Does she associate the idea of being hi 

 with the idea of eating fish and enter accordingly? Thorn- 

 dike endeavored to answer this question by dropping cats 

 into the box through a door in the top, and then feeding 

 them as before when they got out. The cats had the same 

 opportunity of associating the idea of being in the box with 

 the idea of eating fish, but the element lacking was the 

 impulse to walk in through the door. All of these cats, 

 three in number, failed to enter the box after fifty, sixty 

 and seventy-five trials respectively. "Either a cat cannot 

 connect ideas, representations, at all," says Thorndike, 

 " or she has not the power of progressing from the thought of 

 being in to the act of going in. ... The impulse is the sine 

 qua non of the association. The second cat has everything 

 else, but cannot supply that." 



In several other experiments cats and dogs were placed 

 in a box, and the experimenter would take the paw of the 

 animal and make the movement necessary to open the box, 

 after which the animal would be allowed to go out and get 

 food. This was repeated ten or fifteen times and then the 

 animal was left to its own devices. After numerous ex- 

 periments of this sort with various kinds of boxes it was 

 found that the animals uniformly failed to profit by this 

 mode of instruction. None of the animals which failed to 

 get out of a box of their own accord succeeded in escaping 

 after having been several times put through the necessary 

 movements. They had the opportunity to associate the 

 idea of certain movements with escaping and getting food, 

 at least provided they paid attention to what was being 

 done with them. But the animal's own impulse to do the 

 act was lacking. "The animal cannot form an association 

 leading to an act unless the particular impulse to that act 



