290 A MUSICAL PERFORMANCE 



blade of grass in an open place where it can watch 

 for insects passing overhead. When an insect, not a 

 wasp or bee, though it sometimes makes a mistake, 

 comes flying by, it darts swiftly up as if shot from a 

 tube and, clasping its victim with its long spiny legs, 

 brings it to the ground and there struggles with it, 

 prodding it in the softer parts with its proboscis 

 until it is dead. Its ordinary flight is silent, or the 

 humming sound is so low as to be scarcely audible. 

 When the male catches sight of a female seated on 

 a stem he flies to her and balances himself motion- 

 less in the air about three inches from and on a level 

 with her. He then emits a clear sustained humming 

 sound, and after some seconds changes the key to a 

 higher, shriller note; and presently this again changes 

 to a still higher note, so sharp and fine that it is most 

 like the piping of a large species of mosquito. After 

 these three notes the highest and brightest is suc- 

 ceeded by a buzzing sound, like that of a buzzing 

 wasp, but not prolonged, and it comes like measured 

 strokes — buzz, buzz, buzz, and at each repetition the 

 fly drops down a space of about two inches, and at 

 the same time throws out and oars his legs, then rises 

 to the former level; then after this note has been 

 repeated a dozen or more times, again the deeper 

 sustained hum, and all the changes. 



It is all a musical performance, and the only motive 

 one can see or divine is simply the pleasure it gives 

 to the performer; for after it has lasted a long time 

 he flies away, or she flies off and leaves him. But 

 though it ends in nothing, and she sits immobile 



