The Decticus: his Instrument 



unknown to the other singing insects, is 

 worthy of remark. Both sexes are endowed 

 with the sound-producing apparatus. The 

 female, who, in the other Grasshoppers, 

 is always dumb, with not even a vestige of 

 bow or mirror, acquires in this instance 

 a musical instrument which is a close copy of 

 the male's. 



The left scale covers the right. Its edges 

 are fluted with thick, pale nervures, forming 

 a fine-meshed network; the centre, on the 

 other hand, is smooth and swells into an 

 amber-coloured dome. Underneath, this 

 dome is supplied with two concurrent ner- 

 vures, the chief of which is slightly wrinkled 

 on its ridge. The right scale is similarly 

 constructed, but for one detail : the central 

 dome, which also is amber-coloured, is 

 traversed by a nervure which describes a sort 

 of sinuous line and which, under the mag- 

 nifying-glass, reveals very fine transversal 

 teeth throughout the greater part of its 

 length. 



This feature betrays the bow, placed in 

 the inverse position to that which is known 

 to us. The male is left-handed and works 

 with his upper wing-case; the female is right- 

 handed and scrapes with her lower wing- 



269 



