356 'Journal of Comparative Neurology ajid Psychology. 



On Jau. 9, Jan. 13, Jan. 20, lie was tried again and on tlie latter date 

 he opened the trap door ten times in twenty-seven minutes. He was then 

 counted to haA'e learned sufficiently to set the copy for No. 1. 



C. Behavior of No. 1. 



Preliniiuanj trials. — No. 1 was first put into the experiment box on Jan. 7. 

 She was quite hungry and scolded and chattered all the time. She picked 

 crumbs from the floor and climbed the wire on the front and the end of 

 the cage. During the thirty minutes she was in the cage she took no notice 

 of the chute. 



On thirteen succeeding days for the same length of time she repeated this 

 behavior. On Jan. 21, her jumping about the cage jostled open the trap 

 door. This called attention to the door and several times later she climbed 

 the front of the cage and reached one hand over to the edge of the door. 

 There was, however, no evidence that the chute and door were connected by 

 the animal. 



Imitation tests. No. 1 imitating No. 2. — First test. At this time, it seemed 

 evident that No. 1 would not of her own accord learn to work the device. 

 For the imitation test she was placed within a wire-covered box, inside and 

 at the end of the experiment cage opposite the chute. No. 2 was then 

 placed in the cage and allowed to open the food door. The small box served 

 as a place from which No. 2 could jump to the chute and thus modified the 

 conditions of the experiment. The box was removed and the two animals 

 were placed in the large cage together. Prof. Yerkes was present and we 

 were agreed that out of the seven times which No. 2 opened the door, No. 1 

 saw the entire performance twice, and in part, at least, four other times. 

 No. 2 was removed from the cage and No. 1 was left alone for thirty minutes. 

 The following observations are quoted from Prof. Yerkes' notes : "After a 

 few minutes of climbing about. No. 1 looked up at the chute from the 

 floor, stood on her feet, lifted her body and face upward, climbed the side 

 of the cage as if she were making right for the chute, but she did not jump 

 across to it. I am not certain tliat she looked across at the chute from the 

 side of the cage. During the remainder of the interval I saw no evidences 

 of the influences of what she had seen." 



Second test. No. 2 was again placed in the cage and allowed to operate 

 the mechanism. Each time No. 1 got food; sometimes she took all of it. 

 Twice again she saw the entire performance and four times more she 

 saw it in part. No. 2 was then removed and No. 1 was left in the cage 

 for thirty minutes. There were no indications that the l)ehavior of No. 2 had 

 in any way influenced the behavior of No. 1. 



The test was repeated on sixteen difiCerent days. No. 2 operated the device 

 a total of 253 times. No. 1 saw 204 of these. On no day did she see the 

 entire performance fewer than thx-ee times nor oftener than twenty times 

 (see Table 2). 



On each day, after being given the opportunity to witness the behavior of 

 No. 2, No. 1 was left in the cage alone for thirty minutes. On Feb. 6, after 

 being alone for a few minutes, No. 1 stood under the chute and looked up at 



