The Locusts: their Organ of Sound 



more than this similarity between the two 

 surfaces is that all these nervures are smooth. 

 Lastly, the lower edge of the wing-cases, the 

 edge rubbed by the thighs which serve as a 

 bow, also has nothing particular about it. 

 We see, as Indeed we do all over the wing- 

 cases, nervures that are powerful but de- 

 void of any rasping roughness or the least 

 dentlculation. 



What can this artless attempt at a musical 

 instrument produce ? Just as much as a dry 

 membrane will emit when you rub It. And 

 for the sake of this trifle the Insect lifts and 

 lowers Its thighs. In sharp jerks, and Is satis- 

 fied with the result. It rubs Its sides very 

 much as we rub our hands together in sign 

 of contentment, with no intention of making 

 a sound. That Is Its own particular way of 

 expressing its joy In life. 



Examine it when the sky Is partly ob- 

 scured and the sun shines Intermittently. 

 There comes a rift In the clouds. Forthwith 

 the thighs begin to scrape, increasing their 

 activity as the sun grows hotter. The strains 

 are very brief, but they are renewed so long 

 as the sunshine continues. The sky becomes 

 overcast. Then and there the song ceases, 

 to be resumed with the next gleam of sun- 



371 



