THE HIGHER ORGANISMS 171 



so as to cause external activities of the organism, which 

 usually characterize a whole species and are usually 

 adaptive." 



It is usually characteristic of instinctive acts that they 

 are performed but once, or if repeated, are done again and 

 again under the same conditions without substantial 

 change. It even sometimes happens that any interrup- 

 tion in the proceeding may make it necessary to begin 

 again at the very beginning instead of continuing from 

 the stage of interruption. The 'act is automatic rather 

 than rational and consecutive. Thus, when the Peck- 

 hams, on one occasion, stole a spider that a female Pom- 

 pilus quinquenotutus was about to carry into her sub- 

 terraneous nest, the insect, discovering its loss, repaired 

 it by capturing a new spider, for which it then proceeded 

 to dig another nest instead of utilizing that previously 

 prepared and now abandoned. 



Careful observation of the multitudinous and multi- 

 farious forms of instinctive action among animals results 

 in the conclusion that instinct consists of serial and 

 elaborately coordinated reactions, to stimuli arising within 

 or without the. animal, occurring in regular order and 

 eventuating in fairly uniform results. 



That the end-results of the instinctive acts of animals 

 of the same kind are not uniform and invariable is no more 

 than is to be expected when one considers that the animals 

 themselves, though of the same species, are not invariable. 

 In morphology the variations show themselves in size, 

 strength, brilliance of coloring, agility, etc.; in their be- 

 havior the differences appear as carefulness and careless- 

 ness in the details of performance. 



Many observers, however, find it difficult to escape the 

 conviction that associated with instinctive behavior there 

 is at least a glimmering of intelligence. The animal 

 seems to appreciate the fact that it is doing something 

 and to know what it is about. This brings us to a brief 

 consideration of intelligence. 



Intelligence. Intelligence is shown by the adaptation 



