332 C. H. TURNER. 



about, gently squeezed and thrown upon its back. This was 

 repeated over and over again, sometimes in one order and some- 

 times in another. After the moth had quieted down, the pipe 

 was sounded five times in rapid succession. Each time the pipe 

 was sounded, the moth waved its wings vigorously. At intervals 

 of two hours, this experiment was repeated from early morning 

 until dark. Invariably the moth responded in the same manner. 

 On the following day the experiment was continued with the 

 same moth. The result was always the same. 



About a week later, similar experiments were conducted with 

 two other specimens of the same moth. These, like the one used 

 above, were females. With two exceptions, the results were 

 identical. The exceptions were as follows: (i) one of the moths 

 instead of moving its wings vigorously moved them slowly; the 

 other two moths moved their wings so vigorously that they were 

 lifted off of the support; in this case the body remained on the 

 support, although the wings moved each time the whistle blew; 

 (2) on two occasions a moth that had been experimented upon 

 several times, instead of waiting for the five tones that were 

 produced after the handling, waved its wings vigorously to each 

 of the five preliminary notes. Evidently Telea polyphemus can 

 hear. These experiments induced in those moths a state of 

 nervous excitability which caused them to respond to the sounds 

 produced. 



CONCLUSIONS. 



1. It seems certain that all four of the species of giant silk- 

 worm moths investigated can hear. Three of the species respond 

 readily to a large range of sounds. The third, Telea polyphemus, 

 normally does not respond to sounds; unless remaining as im- 

 mobile as possible be considered a response. By experimentally 

 causing the moth to associate some disagreeable experience 

 with certain sounds, it can be induced to respond to those 

 sounds. 



2. There is much evidence that the responses of moths to 

 stimuli are expressions of emotion. The fact that an insect 

 does not respond to a sound is no sign that it does not hear it. 

 The response depends upcn whether or no the sound has a life 

 significance. 



