PSYCHICAL FACULTIES OF ANTS AND OTHER INSECTS. 589 



wasps noticed this immediately, showed symptoms of disgust, and did 

 not return. When he replaced the honey with alum the}' at first 

 came back, but after experiencing the unpleasant taste ceased to come. 

 It may be said, by the way, that this is also a testimony as to their 

 memory for tastes and their power of association. 



Various organs for hearing have been described. The auditory 

 reactions do not change, however, after the removal of such organs, 

 whicli leads to the supposition that there is a sort of pseudo-audition 

 by means of a perception of delicate vibrations through the tactile 

 organs (Duges). 



The tactile sense has for its organs tactile hairs or tactile papilhe. 

 It reacts especially to delicate vibration-s of the air or of the support. 

 Certain articulate animals, especially spiders, orient themselves pref- 

 erably^ by means of the tactile sense. 



It ma}^ be demonstrated that insects are accustomed to combine their 

 various senses for the orientation and recognition of the outer world 

 according to the species and the needs of their life. Eyes and vision 

 are wanting in many species. Others, on the contrary, have a very 

 dull olfactory sense; certain forms lack tactual smell — for example, 

 most of the diptera. 



The great power of orientation possessed by some aerial animals, like 

 ])irds (carrier pigeons), bees, etc., demonstral)ly depends upon vision 

 and visual memories. It is of enormous value in aerial flight. The 

 semicircular canals of the auditory nerves provide a sense of equilib- 

 rium and give sensations of acceleration and turning (Mach-Breuer), 

 but they do not orient the individual as regards the outer world. A 

 specific power of orientation, magnetic or otherwise, independent of 

 the other senses does not exist. 



Taking these senses as elements, we have a basis for insect ps}"- 

 chology. 



Domain of 2)<^rc€2)tion. — It may be considered as established that 

 many insects (apparently all in some rudimentary degree) possess 

 memory, i. e., the power of storing up sense impressions in their brains 

 and turning them to account later. Bees, wasps, etc., will find their 

 way back to a concealed place, not visible from their nest, where they 

 had found some substance they liked, even after its removal and when 

 days and weeks have elapsed. They do this, too, by flight through 

 the air, during wind and rain which would remove every trace of odor, 

 and even after excision of their anteini.e. 



The topochemical sense possessed by the antennee also gives excel- 

 lent evidence as to the possession of memory by ants, bees, etc. An 

 ant will make a difficult journc}', sometimes as far as 80 meters, from 

 a nest that has been destroyed, and, finding there a place suitable for 

 building a new nest, will return (orienting itself with its antenna^), 

 and seize a companion, which he rolls around himself and carries to 



