Modification by Experience 



271 



gradual learning by a gradual elimination of unsuccessful 

 movements and a gradual reenforcement of the successful 

 one, these are unanimous, save in the very hardest, in 

 showing a process of sudden acquisition by a rapid, often 

 apparently instantaneous abandonment of the unsuccess- 

 ful movements and selection of the appropriate one, which 

 rivals in suddenness the selec- 

 tions made by human beings 

 in similar performances" 

 (708). Kinnaman further 

 complicated the box tests 

 with his Macacus monkeys 

 by constructing " combina- 

 tion" fastenings, which re- 

 quired the performance of a 

 set of actions in a certain 

 order, and found that these 

 were mastered by the animals 

 (401) (Fig. 14). 



Cole's (134) work on the 

 raccoon indicates that in speed of learning this animal 

 stands "almost midway between the monkey and the 

 cat," while "in the complexity of the associations it 

 is able to form it stands nearer the monkey." The rac- 

 coons, like the monkeys, learned combination locks, al- 

 though they did not learn to perform the various move- 

 ments involved in a definite order. They showed an in- 

 teresting tendency to skip at once to the movement that 

 immediately preceded the opening of the door. The 

 porcupine also proved gifted with the ability to learn com- 

 bination locks (651), while the squirrel's puzzle-box ex- 

 ploits were limited to boxes which could be entered by the 

 simple process of digging in sawdust (832). The learning 



FIG. 14. Combination fastening used 

 in Kinnaman's work on monkeys. 

 The figures indicate the order in 

 which the parts of the combination 

 had to be dealt with. 



