Modification by Experience 297 



and similar observation was made where the mechanism 

 was a lever. Haggerty (281), as the result of long obser- 

 vation and experimenting on the monkeys in the Bronx 

 Zoo, got some excellent instances of inferential imitation, 

 of which one may be quoted. The act to be performed 

 was that of climbing up the side of the cage, thrusting the 

 arm up inside a wooden chute, and pulling a string inside 

 it, as a result of which food came tumbling down. Mon- 

 key number 13 was allowed to watch monkey number 4 

 go through this process four times. "Number 4 was now 

 removed and Number 13 was released in the cage. At 

 first he looked about over the floor for food and then 

 climbed the front wire, stopping on the brace opposite the 

 chute. He leaned over to the chute and while still stand- 

 ing on the brace with his feet, tried to thrust a hand into 

 the bottom of the chute. Failing in this, he ran along the 

 brace . . . and back again to opposite the chute ; catching 

 the rung of the chute in his hands he drew himself over to 

 it ; finding himself above the end of the chute he tried to 

 let his body down, first on one side and then on the other, 

 until in the most awkward manner he managed to get near 

 enough to the end to thrust a hand up the inside far enough 

 to reach the string. At once he pulled and the food came 

 tumbling down on his chest and to the floor. Dropping to 

 the floor he picked up the food and ate it" (281, pp. 

 360-361). Such persistence of endeavor to carry out a 

 definite act would certainly in a human being be guided 

 by ideas. 



Again, in Hunter's (350) work by the Delayed Reaction 

 Method, the raccoons showed behavior which would seem 

 to indicate the presence of a memory idea. Although 

 they could not go in the right direction if more than twenty- 

 five seconds had elapsed since the light was turned off, 



