Page:American Journal of Psychology Volume 21.djvu/72

62 was used to pull the door open when the latch was raised. He had opened the door some three times in all prior to the 123rd test. At this time the strings were removed to the niche in the left end, place 3, but just around the corner from where they were. As may be seen from the results, Jim made this transition with very little if any difficulty. He continued to do so for four more tests when Young Crow 1 opened the door from the top of the box. In the next Jim struck at the string but missed, when Young Crow 1 at once pulled the same string. Both worked at exactly the same time in the third trial following. In succeeding trials the Young Crow often opened only after Jim had made one attempt.

On the 146th trial the strings were changed to the rear position on the left end. Jim opened the first time, but had to make three different approaches. He looked for the strings in the old position, as did the Young Crow 1 in the next trial, before working them in the new location. In the next two trials Jim made attempts on the old positions.

From the standpoint of imitation the results of this series now come to be more interesting. Young Crow 1 pecked at the top of the door a great deal. Young Crow 2 had now been placed in the cage. Jim struck the door sixty-two times or until Young Crow 1 pulled the string and opened it. The extent to which the latter understood what he was doing may be guessed from the fact that he went on pulling after the door was open. Young Crow 2 was successful next time, and he, too, continued to pull as the other had done. In the next Jim made seventeen errors by working on the door and the rubber band.

Several trials later Young Crow 1 stood on the ground and opened the door as Jim did. It is very difficult to classify this as imitation, though he did it a number of times, for the reason that this crow was so versatile. He did everything to the box in every way in which he could peck or pull at any part of it. He even went so far as to stand on the ground and pull the same string as Jim. Inasmuch as he had the same day stood on top and struck at the top string immediately after Jim opened by using the lower string we may call it imitation according to the more difficult criterion. It involved' a change from previous behavior.

In order to make a place for the strings on the rear side of the box so that this series should correspond exactly with that on the Sparrows, etc., Series A, the boards were removed and posts and wire were put in on the rear, Fig. 22. This change made Jim and even Young Crow 1 afraid whenever they caught sight of the wire. This caused the times to be somewhat longer.