Modification by Experience 293 



observation that his dogs and cats were not helped to learn 

 a puzzle-box mechanism by being put through the move- 

 ments. The absence of ability to pass from the experience 

 of being put through a movement to the idea of performing 

 the movement is no proof of incapacity to form ideas; 

 moreover Cole (134) found that the raccoon did learn to 

 work a fastening by being put through the movements. 

 Hunter (351) made a similar observation on the rat, and 

 the method seems to meet with success in the hands of 

 animal trainers. 



In general, however, we must admit, the facts point 

 to the conclusion that ideas are very rare in the animal mind. 

 We can in some cases, however, present positive evidence 

 of their occurrence. One attempt to demonstrate them, 

 that of Cole (134), it is true, seems hardly conclusive. Cole 

 trained raccoons to discriminate between various stimuli. 

 Cards were placed on levers so that by a touch they 

 could be pushed up and down. The animals learned to 

 climb up for food when one of two differently colored 

 cards was shown, and to stay down when the other one 

 appeared; to distinguish in a similar way between a 

 high and a low tone, between a round and a square 

 card, and between a card 6f X 6| inches and one 4I X 4^ 

 inches square. Of course the action of climbing up was 

 not itself purely instinctive, but had become associated 

 with the food instinct. The raccoons also hit upon 

 the trick of clawing up the cards themselves, and if 

 the one that appeared was the "no-food" card, they would 

 either claw it down again and pull up the other, or proceed 

 at once to pull up the other, leaving the "no-food" one 

 also up. Since the cards were shown successively. Cole 

 concludes that "remembrance of the card just shown was 

 required for a successful response." "Why," he asks, 



