MENTAL LIFE OF MONKEYS AND APES 87 



almost incredible that he should continue, day after day, to 

 make incorrect choices in a particular setting while choosing 

 correctly in some other setting which from the standpoint of 

 the experimenter was not more difficult. 



The evidence suggests that in this young orang utan idea- 

 tional learning tended to replace the simpler mode of problem 

 solution by trial and error. Seemingly incapable of solving 

 his problems by the lower grade process, he strove persistently, 

 and often vainly, to gain insight. He used ideasin effectively. 

 Animals far lower in intelligence (e. g., the pig), surpass him in 

 ability to solve these relational problems because they use the 

 method of elimination by trial consistently and effectively. 

 Julius, in these experiments, made a poor showing because his 

 substitute for trial and error is only slightly developed. Would 

 he have succeeded better with the same problems if mentally 

 mature? 



There are many important features of the results which, for 

 lack of space, have not been indicated or discussed. They can 

 be developed from later comparative studies of the data, for 

 in the tables appear all of the essential facts of response apart 

 from those mentioned in the text. 



