AUDITORY POWERS OF GIANT SILKWORM MOTHS. 



331 



TABLE XII. 



EFFECT OF AGE ON THE RESPONSES OF Callosamia promethea TO SOUND. 



reasonable to conclude that they hear. How about Telea poly- 

 phemus? Of the seventy-eight individuals whose behavior is 

 recorded in Table II. only three made any responses whatever. 

 Of these three, two gave over ninety per cent, of responses and 

 the other less than thirty. Shall we conclude that Telea poly- 

 phemus is deaf and that these few responses were due to some 

 factor overlooked by the investigator; or, shall we consider the 

 responses made by all of these moths as expressions of emotion, 

 and attribute the non-responsiveness of polyphemus to a sluggish 

 temperament? 



To one who has worked much with Telea polyphemus, this last 

 suggestion is fascinating; for this moth is exceptionally un- 

 responsive to all ordinary stimuli. The opposite sex is about 

 the only thing that arouses much activity. There is another 

 possibility. Telea polyphemus is not a very conspicuous object; 

 indeed, in certain situations, it might be considered protectively 

 colored. It may be that correlated with this inconspicuous 

 coloration is an instinct to remain rigidly immobile in the presence 

 of all ordinary stimuli. To test the matter the following experi- 

 ments were conducted. 



A freshly emerged Telea polyphemus, the wings of which had 

 become thoroughly dry, was tested with an organ pipe set to 

 produce 256 vibrations per second. As was to be expected, 

 there was no visible response. The organ pipe was then sounded 

 five times in rapid succession. Immediately thereafter, the 

 insect was roughly handled for a few minutes. It was tossed 



