The Senses of Animals. 267 



an auditory organ, as shown by Sir John Lubbock, in the 

 tibia of the front leg. But in locusts it is situated on the 

 first segment of the abdomen. In flies there are a number 

 of vesicles, generally regarded as auditory (but by some as 

 olfactory), at the base of the rudimentary hind wings the 

 so-called halteres, or balancers. 



Observation seems to point to the fact that in most 

 insects the sense of hearing is lodged in the feelers, or 

 antennae. Kirby made the following observation on a little 

 moth : " I made," he says, " a quiet, not loud, but distinct 

 noise; the antenna nearest to me immediately moved 

 towards me. I repeated the noise at least a dozen times, 

 and it was followed every time by the same motion of that 

 organ, till at length the insect, being alarmed, became 

 more agitated and violent in its motions." Hicks wrote, 

 in 1859, " Whoever has observed a tranquilly proceeding 

 Capricorn beetle which is suddenly surprised by a loud 

 sound, will have seen how immovably outward it spreads 

 its antennae, and holds them porrect, as it were, with great 

 attention, as long as it listens." The same observer 

 described certain highly specialized organs in the antennas 

 of the hymenoptera (ants, bees, and wasps), which he thus 

 describes : " They consist/' he says, " of a small pit lead- 

 ing into a delicate tube, which, bending towards the base, 

 dilates into an elongated sac having its end inverted." Of 

 these remarkable organs, Sir John Lubbock says there are 

 about twelve in the terminal segment, and he has suggested 

 that they may serve as microscopic stethoscopes. 



Mayer, experimenting with the feathered antenna of 

 the male mosquito, found that some of the hairs were 

 thrown into vigorous vibration when a note with 512 

 vibrations per second was sounded. And Sir John Lubbock, 

 who quotes this observation, adds,* "It is interesting 

 that the hum of the female gnat corresponds nearly to this 

 note, and would consequently set the hairs in vibration." 

 The same writer continues, " Moreover, those auditory 

 hairs are most affected which are at right angles to the 



* " Senses of Animals," p. 117. 



