PHYSIOLOGY OF THE INVERTEBRATA. 435 



movement of the extensor and deflexor muscles ; and the 

 grasshoppers to the same end employ the subtile elevator 

 and depressor muscles of their agile leaping legs," 



The following table gives the orders of the Insccta which 

 possess the power of emitting musical sounds : — 



Many sounds emitted by insects are certainly not musical 

 to the human ear ; nevertheless, as the latter is only capable 

 of appreciating sonorous vibrations within narrow limits, the 

 sounds produced by the Inseda may be musical to them ; at 

 any rate these sounds have their uses, or the organs which 

 produce them would not be so well developed as they are in 

 the Inseda. If many of us are incapable of appreciating 

 insect music, the ancients, and especially the Greeks, appear 

 to have regarded it with feelings of great satisfaction ; and 

 the Cicada is often referred to by certain Greek poets. 

 Anacreon, for instance, has devoted an ode to singing the 

 happiness of this insect. An element of this happiness, 

 according to Zenachus, is, that the Cicadcv] "all have 

 voiceless wives," an opinion which will probably find sup- 

 porters in the joresent day. 



Besides stridulation, many insects produce sounds by 

 means of their wings (wing-beating), and stigmata, spiracles, 



* Various Cicadce, 



t For a full description of these insects, see Buckton's Monograph of the 

 British Ciccuhi: or Ttttifjldce. 



