96 ETEXIIfGS AT THE MICROSCOPE. 



tiiisr both off, he examined the mutilated flv with a mi- 

 croscope, and found tliat the remaining fragments of 

 the wings were in constant motion all the time that the 

 buzzing continued ; but that by pulling them up by 

 the roots, all sound ceased. Sh elver's experiments go 

 to prove, with respect to the insects that he exam- 

 ined, that the winglets are more particularly concerned 

 with the buzzing. Upon cutting off the wings of a fly 

 — but he does not state that he pulled them up by the 

 roots — he found the sound continued. lie next cut off 

 the poisers — the buzzing went on. This experiment 

 was repeated eigliteen times with the same result. 

 Lastly, when he took off the winglets, either wholly or 

 partially, the buzzing ceased. This, however, if cor- 

 rcL't, can only be a cause of this noise in the insects 

 that have winglets. Kumbers have them not. He 

 next, therefore, cut off the poisers of a crane-fly {Tipula 

 crocata)^ and found that it buzzed when it moved the 

 winii;. lie cut off half the latter, vet still the sound 

 continued ; but when he had cut off the whole of these 

 oro-ans the sound entirely ceased." * 



There is a pretty little beetle {Clf/tus), not uncom- 

 mon in summer in gardens, remarkable for the brilliant 

 gamboge-yellow lines across its dark wing-cases, which 

 makes a curious squeaking sound when you take it in 

 your hand. You think it is crying ; but if you care- 

 fully examine it with a lens M'hile the noise is uttered, 

 you will perceive that the cause is the grating of 

 the thorax against the front part of the two wing- 

 cases. Several other beetles produce similar sounds 

 when alarmed, bv rubbinoj the other end of the wing- 

 sheaths with the tip of the abdomen. Many of 



* Introd. to Entom. Lett. xsiv. 



