AUDITORY POWERS OF GIANT SILKWORM MOTHS. 327 



reasons why the thresholds cannot be accurately determined by 

 this method and partly on account of practical difficulties, I 

 confined my experiments to a few notes of the middle range. 

 When I remind you that I often had on hand from fifty to 

 seventy-five moths, you will readily see that it was impossi- 

 ble to test each moth, each time, with the entire range of 

 pitches. 



The results of these investigations were recorded upon blanks 

 that were prepared especially for this work. A portion of one 

 of those blanks is reproduced in the preceding table. 



After the work on all of the moths had been completed, the 

 contents of these blanks were condensed into the following tables. 



TABLE II. 



REACTIONS OF GIANT SILK-WORM MOTHS TO SOUNDS. 



1 The above table does not record the three specimens of T. polyphemus, which 

 were used in the special tests recorded on pages 333-334. 



