1919] Walker — Synchronous Movements in Vanessa antiopa Larvce 15 



not auditory and probably not olfactory, though the function is 

 doubtless a mechanical one." 



Before passing from mechanical considerations, it should be 

 noted that the telephone receiver and transmitter are practically 

 of the same construction, and while rejecting any electrical influ- 

 ence, if insects are equipped with means for receiving vibrations, 

 it may also be possible for them to transmit them. 



In the matter of the attraction of the males of certain species of 

 moths by the females at apparently long distances, Fabre notes 

 that the male moths came with the wind at one time, and that the 

 reflux of scented atoms in a direction contrary to the aerial current 

 seems inadmissible. 



I have tried the experiment of fastening a female turnus butterfly 

 to a twig with varying results. On one occasion during the summer 

 of 1917 I captured what appeared to be a freshly emerged specimen 

 of this species and even before the act of securing it to a leaf was 

 completed, the males began to arrive and I took about twenty 

 specimens in a short time. They came from many directions, some- 

 times varying greatly from a direct line but always reaching the 

 goal. If I remember correctly a light air was stirring, the butter- 

 flies coming with the wind as well as against it. The sense of 

 smell was doubtless the controlling factor for a limited distance, as 

 however erratic the flight at a distance the course was direct in 

 the last few rods. 



Smell concerns matter and it is diflacult to conceive of the divis- 

 ibility of matter to such an extent as to fill the air with scent atoms 

 unperceived by the human sense of smell particularly against the 

 wind or in the absence of perceptible air currents except for limited 

 distances. Fabre^ endeavored to mask or stifle any possible 

 effluvia emanating from his female moths by surrounding them 

 with various noxious odors but apparently without the slightest 

 effect, the males arriving in undiminished numbers and without 

 hesitation. 



In strict justice to the case of Sympathetic Vibratory Communica- 

 tion vs. The Sense of Smell, I shall have to testify for the de- 

 fendant in so far as to say that a female dog belonging to a 

 neighbor at certain times seemed to attract the males from all 

 directions regardless of air currents; and her only known external 

 vibratory organ had been amputated in infancy. 



> Life of the Caterpillar, pp. 275, 276. 



