Sensory Discrimination : Hearing 113 



vibrations responded to were those which were communicated 

 through the solid on which the ants stood, and received 

 through the legs (125). It is probable that the observers 

 who have come to opposite conclusions have not in every 

 case been careful to exclude the possibility of such vibration 

 of the substratum. Wasmann, for instance, thinks he has 

 seen reactions to sound; he noted that ants in an artificial 

 nest raised their antennae and lifted the fore part of their 

 bodies when he scratched with a needle on some sealing wax 

 with which the nest had been mended (423). He also quotes 

 Forel's account (129) of a species which makes an " alarm 

 signal" by striking the ground with its abdomen: this, 

 remarks Wasmann naively, must be perceived by the ants, 

 " otherwise it would not be an alarm signal"! (424). If 

 perceived, it may of course be as a tactile rather than an 

 auditory sensation. Weld has observed reactions to the 

 sound of whistles and tuning forks in several species of ants, 

 and even concludes that they perceive the direction from 

 which sounds come ; but since, of the four observations upon 

 which this latter opinion is based, two were cases where the 

 ants hurried toward the sound and the others cases where 

 they backed away from it, the possibility of mere coinci- 

 dence seems not to be excluded (433). 



As regards the auditory sense in bees, there is again a 

 difference of opinion. They do, of course, make sounds, 

 and sounds of different quality, under different conditions. 

 Yet Lubbock entirely failed to get bees to respond to any kind 

 of sounds artificially produced (248), while Bethe urges that 

 the sounds produced by bees are involuntary, like the sounds 

 of our own breathing and heart-beats, and that there is no 

 more evidence that bees can hear them than that we can hear 

 these sounds in our own case (32). Forel is positive that 

 insects in general cannot hear (130). Von Buttel-Reepen, 



