INSECT BEHAVIOR 365 



the worker Polistes does not learn to feed the larvae by imi- 

 tating the queen. 



It is extremely difficult, however, if not impossible, to draw 

 the line between instinct and intelligence ; and in doubtful cases 

 there is a general tendency to exaggerate the importance of 

 intelligence rather than that of instinct. For example, the 

 well-known discrimination on the part of ants between mem- 

 bers of their own colony and those of other colonies, even of 

 the same species, would seem to imply intelligent recognition. 

 This recognition, however, is due simply to a characteristic 

 odor, which is derived from the mother of the community. 

 An ant after being washed receives hostile treatment from 

 others of its own colony; while an alien ant after being 

 smeared with the juices of hostile ants is treated by the latter 

 as a friend. 



Each instance of apparent intelligence must be examined 

 impartially on its own merits. At present it may be said that, 

 while most of the behavior of insects is purely instinctive, there 

 is some reason to believe that at least gleams of intelligence 

 appear in the most specialized Hymenoptera. 



Lack of Rationality. However intelligent the social Hy- 

 menoptera may be in their way, they show no signs of the 

 power of abstract reasoning. Even ants, according to the 

 experiments of Lubbock, display profound stupidity in the 

 face of novel emergencies when they might extricate them- 

 selves by abstract reasoning of the simplest kind. The 

 thoughts of an ant or bee seem to be limited to simple associa- 

 tions of concrete things. Miss Enteman observed a Polistes 

 worker which gnawed a piece out of the side of a dead larva 

 of its own kind and, turning, actually offered it as food to the 

 mouth of the same larva. In another instance, a larva was 

 attacked and killed, and then offered a piece of its own body. 



Such examples as these emphasize the strength of the reflex 

 factor in the behavior of insects. Indeed, the basis of all 

 behavior is being sought in the reactions of protoplasm to 

 external stimuli. Possibly even memory, consciousness and 

 other attributes of intelligence will eventually be reduced to 

 this basis, improbable as it may now seem. 



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