THE MOSQUITO 67 



man, the male is primarily the hearer, the 

 one who has to listen. 



Another American, Mayer, twenty years 

 later made some interesting experiments con- 

 firming the views held by Johnston. He man- 

 aged to cement with shellac a species of Culex 

 on to a glass slide, and, placing it beneath a 

 low-powered microscope, watched the response 

 of the antennae to tuning-forks of varying 

 strengths. He found that under the influence 

 of a fork producing 512 vibrations per second 

 certain hairs of the antennae vigorously 

 vibrated, whilst others were left unmoved. 

 He measured the amplitudes of the vibrations 

 of these hairs under the influence of the 

 sound emitted by various tuning-forks. Dif- 

 ferent hairs were seen to vibrate to different 

 notes. Mayer also observed that when the 

 sound came from a direction in line with the 

 long axis of the antennary hair vibrations 

 ceased altogether. Hence he argued that the 

 antennae could register the direction whence 

 the sound came. Observing the antennae 

 under the microscope, he confirmed the view 

 that the vibrations ceased when the hairs 

 pointed towards the source of sound, and on 

 drawing a line in the direction in which the hair 

 pointed, he found that it always cut within 5° 

 of the position of the source of sound. He 

 concludes : — 



F 2 



