420 C. H. TURNER 



retecta, var. luctuosa, C. robinsona, C. vidua, C. arnica, C. epione, 

 C. neogama, C. ilia, and C. innubens. The human voice, the 

 Galton whistle and organ pipes were used to produce sounds. 

 Except for special reasons, these instruments were always sounded 

 where they could not be seen by the insect. To test the ability 

 of the moths to respond to sounds to which they were usually 

 passive, the following method was employed. Simultaneously 

 with the sounding of the note the moth was gently touched. 

 This was repeated one or more times and then the pitch was 

 sounded without the tactile sensation. These authors reached 

 the following conclusions: — " 1. Our field experiments demon- 

 strate that several different species of Catocala moths respond 

 to certain high pitched notes of the Galton whistle; but that 

 they do not usually respond to notes of low pitch, such as the 

 rumbling of trains, etc. 2. Most specimens responded to a high 

 note by flying to a nearby tree*; but some, and this was especially 

 true of C. retecta, responded by making quivering movements with 

 its wings. 3. The degree of responsiveness was not the same for 

 all species. Among the least responsive were C. vidua, C. neo- 

 gama; and at the other extreme were C. flebelis, C. kahilis and 

 C. Robinsoni. 4. We do not consider the failure of these moths 

 to respond to certain sounds of a low pitch a proof that they 

 do not hear such sounds; indeed, we are inclined to believe 

 that these creatures respond only to such sounds as have a 

 life significance. Three things render this last supposition prob- 

 able: (1) the fact that unijuga, which at first did not respond 

 to whistling, did so readily after once a blast of air had been 

 allowed to strike her body simultaneously with the sounding 

 of the whistle; (2) that most of the natural enemies of these 

 moths produce high pitched sounds and trains and brass bands 

 and other producers of low pitched sounds do not directly affect 

 the survival of these moths; and (3) by carefully conducted 

 field experiments we were able to induce three specimens of 

 C. neogama to respond to sounds to which the species does not 

 usually react." 



Turner (86) reports the results of laboratory experiments with 

 79 specimens of Samia cecropia Linn., 104 of Philosamia cynthia 

 Drury, 41 of Callosamia promethca Drury, and 81 of Telea poly- 

 phemus Cramer. These experiments were conducted in a build- 

 ing so constructed that it was impossible for the vibrations of 



