226 MIND IN EVOLUTION CHAP. 



ments, in which he had learnt to get food by the method 

 by which I had previously got it for him ; and the ques- 

 tion therefore seemed here to come to a head. If he was 

 influenced by what he saw me do, there would be some 

 tendency to pull the string which 1 had pulled. But if 

 this influence was subordinate to the desire of getting the 

 biscuit, he would soon learn that for once he was wrong in 

 following me ; and he would as before take to watching 

 where the biscuit was put, and pulling the string that led 

 to that place. This is in fact what fell out. In the first 

 four trials, he three times pulled the string which I had 

 pulled previously. 1 After this, he six times in succession 

 pulled the right one, to the neglect of that which I had 

 pulled before. 



This experiment seemed to me to show at once the 

 influence of previous perception, and its subordination to 

 the results connected with it. The experiment also illus- 

 trated once more the function of attention. Comparing 

 its earlier and later stages, it would seem that Jack's 

 attention was rapidly cultivated. He began with great 

 carelessness ; and his successes were actually below the 

 average of pure chance. By the end of the day, he had 

 improved so much as to be nearly always right. 



Tied cord. 



I was struck by a performance of the chimpanzee with a 

 cord which I had knotted round a bar outside his cage. 

 He was accustomed to pulling in food by means of this 

 cord, and I wished to see how he would act if I tied the 

 cord round a staple, so that the end in his possession 

 became inoperative. I found that without any hesitation, 

 he "made a long arm," and reached beyond the knot ; and 

 I thought it would be interesting to compare the action of 

 other animals on this point. I therefore arranged a cord 

 for Jack's benefit, which passed from the leg of a table 

 diagonally upwards, round a support of the sideboard at 

 about three feet from the ground, and from there up to a 



1 At the first trial he nearly pulled the right one, but passed to mine. 

 Both strings fell. In the third trial he pulled neither the right string nor 

 mine. It must be added that each time, after having pulled down the 

 card, I replaced it immediately before placing the biscuit on another card, 

 so that his attention to the wrong card was maintained. 



