THE PROBLEM OF LEARNING 1 85 



the caterpillar off. The caterpillar elicited no fur- 

 ther response during the next forty-five minutes. 

 For four days the frogs were scantily fed and then 

 a caterpillar was put in the cage. Rana sylvatica 

 took no notice of it." This frog had formed the 

 habit of avoiding hairy caterpillars in seven trials, 

 but when the green frog is given lessons in escap- 

 ing from a single labyrinth, about one hundred 

 were necessary before the right route was regu- 

 larly taken. 



Cole made his observations on racoons. The 

 animals were rewarded with food on the success- 

 ful working out of their lesson. He began with 

 simple tasks and increased the details until all 

 of the animals succeeded in learning to work seven 

 fastenings: namely, two buttons, two bolts, lifted 

 by a pull on each of two loops hung in different 

 parts of a large box, one thumb latch, one bolt 

 raised by the animals, mounting a platform and a 

 horizontal hook placed at the left side of the door. 

 In boxes of two to seven fastenings there is almost 

 no tendency to follow a routine order in undoing 

 them. 



As a result of numerous trials extending over 

 several months, it was concluded in part that the 

 long practiced motor associations show a good de- 

 gree of permanence, others are very transient. 

 The racoon presents two types of learning and 

 two types of forgetting. 



