Turner, Homing of Ants. 407 



detect no response whatever. But usually there would be a 

 slight movement of the antennae, or a slight but sudden acceler- 

 ation of speed, or else a halting movement. Sometimes the ant 

 would stop still. All of these movements were slight, usually so 

 slight that they might easily be overlooked by an observer who 

 was not expectmg a response of some kind. 



Even with single individuals confined to a test-tube which was 

 suspended by a string (a method much used by Weld), I some- 

 times obtained no response. Indeed, I seldom received more 

 pronounced responses than a slight movement of an antennae, 

 or a twitch of one or more legs, or a more tense attitude of the 

 body. In most cases, however, I did get these slight movements, 

 and, occasionally, I observed wide sweeping movements of the 

 antennae or other easily observed bodily movements. 



The pronounced positive results obtained by Weld and my- 

 self do not seem to harmonize with the equally pronounced nega- 

 tive results obtained by Huber, Forel and Lubbock. One 

 cannot believe that the American ants are physiologically as much 

 unlike the European as these antagonistic results would seem to 

 indicate. It seems to me that these contradictory results can be 

 harmonized in the following manner. 



Lubbock's experiments were made either upon ants that were 

 carrying pupae home, or else upon ants that were confined to paper 

 bridges. As has been stated above, my experiments show that 

 under such conditions the ants usually do not respond at all to 

 sounds, or else react with movements so slight that they might 

 easily be overlooked by one not expecting movements of the kind 

 made. I am fully convinced that experiments conducted upon 

 European ants colonized in Janet nests, would yield the same 

 positive results obtained by Weld and myself. 



To harmonize Fielde and Parker's ('04) work with mine is 

 not an easy task. We agree that, up to about 4000 vibrations 

 per second, ants respond to a long range of vibrations which a 

 human ear would sense as sounds. They claim that these vibra- 

 tions are responded to only when received through a solid medium; 

 while my experiments seem to show that they are responded to 

 when received through the air. Yet two of the species used by 

 me (F. sanguinea and F. fusca var. subsericea) were also used by 

 them. They used the piano, the violin and the Galton-whistle; 

 I used organ pipes and the Galton-whistle. It seems to me that 



