220 MIND IN EVOLUTION CHAP. 



seeing it done. I kept putting the hook on, and removing it 

 while his attention was distracted by something else. This had 

 no effect ; he merely bit and clawed at the string, and at times 

 succeeded in biting it through. When I substituted wire, he 

 would still pull so hard that the wire sometimes broke. After an 

 interval of some days, I tried the same trick, only showing him. 

 Unfortunately, the hook several times gave, which encouraged 

 him in pulling hard at the wire. It was not until the twentieth 

 trial that he made any attempt at the hook, though he had twice 

 before come to look at it, probably because I called his attention 

 to what I was doing. He then pawed at it a little, but failed to 

 get it off. This seemed to discourage him. He tried at the 

 hook vaguely two or three times afterwards, but never succeeded. 



It seemed indeed that an accidental failure, when the 

 trick was attempted in the way shown, was abnormally 

 discouraging. Thus, I tried Jack with the simple trick of 

 opening a cupboard door by pulling a key arranged so 

 that he could easily get hold of it. He was so quick about 

 this that at the first trial he jumped up to help me to 

 pull, and at the second he began to pull at once. Unfortu- 

 nately, to reach the key he had to put his forepaws on the 

 ledge below the door, and they rested against the door 

 itself, neutralising his efforts to open it. 1 After this 

 failure, though several times shown, he refused to make 

 the slightest effort surely a suggestive result. 2 



5. Habit and Discrimination. 



To these experiments, in so far as they may be 

 offered in proof of learning by perception of results, two 

 objections may be raised. The first is that, after all, 

 each trick might have been performed in the first instance 

 in a more or less random way, and that such an accidental 

 success, not the sight of what the teacher did, would 

 be really responsible for the establishment of the trick. 



1 Instances of animals thus hindering their own actions are fairly 

 common, but both Jack and the elephant frequently showed some adroit- 

 ness in overcoming that kind of hindrance. I thought my Rhesus, 

 Jimmy, very stupid for trying to open his box upward while he sat on the 

 lid, but my respect for him increased when, after many trials, he managed 

 it by sidling to the edge of the hinges. 



2 I mean that the effect was more marked than that of an ordinary 

 failure, and points to more subtle psychological forces than that of bare 

 perception and its application namely, to the dog's confidence in his 

 master and what he points out to him. 



