Page:American Journal of Psychology Volume 21.djvu/70

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60
PORTER

again once each in two different tests, twice again on Aug. 3rd, and again on Aug. 6th. On Aug. 6th the pan of food was removed from just behind the strings to the front left corner. He noted the change but it did not affect his behavior. After three tests the food was placed in the left rear corner but this again made no change in his behavior. It is understood, of course, that each time after the door was opened I placed the food out next the door-sill so that Jim could get it. He would probably starve before entering the box.

On August 5th one of two young crows that were taken from the nest about the first of June and reared by hand was turned into the cage with Jim. The accompanying figure 20, gives a good idea of the tameness of these crows, and yet they were, when a month or so old, somewhat more fearful than as shown in the photograph. If a stranger fed them they might refuse to eat from his hand until very hungry. This young one, which we shall designate as Young Crow 1, was at first inclined to be rather cautious in his approach to the box. On the second day, however, he struck at the wire and nail heads.

On this same day the strings were removed from their place at the right of the door, place 1, and placed to the left of the door, place 2. This change was identical with that made in the box for the birds in Series A and others. It will be seen from the table that nothing was done during seventeen and one-half minutes except some efforts on the wire eyelets where the old strings had been attached. In the 2nd test Jim made fifteen unsuccessful trials in ten minutes and then returned to his perch. In the following trial of ten minutes Young Crow 1 played a good deal on top of the box. The young crows had shown signs of play when in their own cage. Jim made three unsuccessful efforts, but failed in ten minutes. Young Crow 1 opened the door by pulling the top string when standing on top of the box. Jim had already made five attempts during this trial. In the succeeding trial Jim worked very hard. He was successful only after making forty-eight vain efforts on the old side. He seemed to have very strong associations with the old place and not for the strings. The box is so made that the door swings back against these strings. Jim's great fear may well have been increased by this fact. The time required for the next trial was longer. Seventeen errors, all made by working on the old place, were recorded against Jim in this trial. Young Crow 1 was working on the top of the door. He struck it with the beak and jumped back suddenly each time.

By this time Jim showed signs of learning to work on the strings in the new position. There was some little interruption during a few tests at about this time. This was caused by the