HABIT-FORMATION IN A WASP {VESPA SP.). 287 



on the queen Wasp were conducted in the open ah-, the lighting 

 conditions remained unaltered, and tlie instinctive modes of 

 response to specific sensory stimuli were not affected. 



It is hardly worth while attempting to draw any conclusions 

 from a curve of learning based on the reaction times. The 

 learning curve shows the usual raj)id initial descent and subse- 

 quent irregularities, the most of which may readily be explained 

 as being due to the variable nature of the plug used to close the 

 entrance of the burrow. The method of learning was obviously 

 trial and error or, as some prefer it, trial and success. When 

 the normal sequence of motor activities was interrupted by the 

 presence of the plug, the motor energy of the Wasp liberated 

 itself in random movements which were of two kinds, each kind 

 having a different result. The assumption could not, however, 

 be justified that the two modes of response always function 

 differently in the Wasp. In the present instance the distinctive 

 ends of the two types of movement were clearly the result of 

 accident. The high-speed random flights produced no more 

 than the proper direction by means of an accidental success. 

 The slow exploratory random movements gave position, and 

 eventually, by the elimination of useless movements, established 

 an habitual air-line from the plug to the nest. The Wasp had 

 the power to modify its behaviour in a regulatory way, and she 

 had retention. The Wasp had associative memory as defined 

 by Loeb,"^ and intelligence according to the definition of Jen- 

 nings. f The Wasp was able to form an association of a simple 

 kind. She did not connect an old motor-habit with a new 

 sensory stimulus, but formed a new motor-habit in response to 

 a new sensory stimulus. Strictly, one may doubt whether an 

 association was formed at all. There is a difference between 

 the association of a particular movement with a given sensory 

 stimulus and the release of a random, though successful, move- 

 ment by an adequate sensory cue. The former suggests activity ; 

 the latter passiveuess. The former has an imaginal or percep- 

 tual imphcation ; the latter is purely physiological and explicit. 

 The evidence is altogether in favour of the sufficiency of the 

 second explanation to account for the reactions of the Wasp 



* Loeb, 'Comparative Physiology of the Brain,' p. 213, 1900. 



i Jennings, ' Behaviour of the Lower Organisms,' p. 333 et seq., 1906. 



