LEARNING IN THE MONKEY 261 



would usually induce E to come away from the box and give 

 B an opportunity to dash by him. 



In the beginning the study was not intended for publication, 

 so a count of the distinct attempts to reach into the box was 

 not made. It is safe, however, to estimate that D and E each 

 made more than two hundred, probably twice that number of 

 attempts to reach the food and neither seemed to make any 

 progress. They repeated over and over again about the same 

 futile movements. D and E would both often crouch at right 

 angles to the box, look over the bar into the box and thrust 

 their arms through the aperture up to the elbow. Although they 

 would pronate the forearm they could not bend the elbow to 

 lower the hand into the box, being anatomically impossible in 

 the narrow aperture with the body at right angles to the opening 

 and the head above the bar. They would then usually shake 

 the box back and forth or try to lift it or turn it around. 



The observations of two periods are given here to make clear 

 what happened. The period of April 8 is typical of all the 

 periods previous to it. During the period of April 19 D suc- 

 ceeded for the first time in his efforts to obtain food. 



OBSERVATIONS 



April 8. — D and F are in the cage together. Several prunes 

 were dropped into the problem box. D reached through the 

 aperture to the elbow. F pushed his way to the aperture, 

 crouched and extended his arms through the aperture and 

 helped himself to the prunes. D crouched right beside F, watch- 

 ing him intently, especially F's hand reaching for food, and he 

 moved his forearm through the aperture the way F did but did not 

 turn his body properly. He clearly tried to imitate F's method of 

 reaching. (Subjective learning through imitation.) F grabbed 

 all the prunes. A few minutes later F grabbed all the nuts and 

 bread without exception. This is about what occurred each 

 time the problem was tried throughout twelve weeks. 



April 19. — D and F in a cage together. One dried peach 

 was dropped into the box. F grabbed it. D pursued F to take 

 it from him. Piece of dried bread dropped into the box. F 

 grabbed it. Bread again dropped into the box before F finished 

 eating. D turned the box around and pulled it back and forth; 



