Packahd] IXSECTS of THE PLANT HOUSE. 



101 



of his body in the direction of the sound. Experiments 

 under tlie microscope show that the mosquito can thus detect 

 to within five degrees the position of the sonorous centre. 

 To render assurance doubly sure, Prof. Ma^-er, having found 

 two fibrils of the antennae of a mosquito which vibrated pow- 

 erfully to two different notes, measured these fibrils very 

 accurately under the microscope. He then constructed some 

 fibrils out of pine wood, which, though two or throe feet 

 long and of the thickness of small picture-cord, had exactly 

 the same proportion of length to thickness as the fibrils of 

 the antennae of the mosquito. He found that these slender 

 pine rods or fibrils had the same ratio of vibration to each 

 other as the fibrils of the mosquito." 



Here a question arises. The song of the mosquito is un- 

 doubtedly a sexual call. Does the male detect the presence 



Fig. 71. 



Ocean Gn.tt. 



of its female charmer by the different tones of her voice? 

 Certainly the ears of the male with its feathered antennae 

 arc far more acute than those of the opposite sex, the an- 

 tcnujie in her case mostly wanting those long vibratile hairs 

 that give to him his acuteness of hearing. In this case 



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