THE PINE-CHAFER 323 



The sound is produced by the extremity of the 

 abdomen, which gently rises and falls, rubbing, as 

 it does so, with its last few segments, the hinder edge 

 of the wing-covers, which are held firm and motionless. 

 There is no special equipment on the rubbing surface 

 nor on the surface rubbed. The magnifying-glass looks 

 in vain for the fine striations usually found in the 

 musical instruments of the insect world. All is smooth 

 on either hand. How then is the sound engendered ? 



Rub the end of the moistened finger on a strip of 

 glass, or a window-pane, and you will obtain a very 

 audible sound, somewhat analogous to that emitted 

 by the chafer. Better still, use a scrap of indiarubber 

 to rub the glass with, and you will reproduce with 

 some fidelity the sound in question. If the proper 

 rhythm is observed the imitation is so successful that 

 one might well be deceived by it. 



In the musical apparatus of the Pine-chafer the pad 

 of the finger-tip anc the scrap of indiarubber are 

 represented by the soft abdomen of the insect, and the 

 glass is represented by the blade of the wang-cover, 

 which forms a thin, rigid plate, easily set in vibration. 

 The sound-mechanism of the Pine-chafer is thus of the 

 very simplest description. 



