342 



SEXUAL SELECTION. 



[Part IL 



it can be heard during the niglit at the distance of a 

 mile ; " and that made by certain species is not mimusical 

 even to the human ear, so that the Indians on the Ama- 

 zons keep them in wicker cages. All observers agree that 

 the sounds serve either to call or excite the mute females. 

 But it has been noticed " that the male migratory locust 

 of Russia (one of the Acridiidaj), while coupled with the 

 female, stridulates from anger or jealousy when ap- 

 proached by another male. The house-cricket when sur- 

 prised at night uses its voice to warn its fellows." In 

 North America the Katy-did {Platyphyllum concavum^ 



one of the Locustidse) is 

 described ^' as mounting 

 on the upper branches of a 

 tree, and in the evening be- 

 ginning his noisy babble, 

 while rival notes issue from 

 the neighboring trees, and 

 the groves resound with the 

 call of Katy - did - she - did 

 the live-long night." Mr. 

 Bates, in speaking of the 

 European field-cricket (one 

 of the Achetidai), says: 

 "The male has been ob- 

 served to place itself in the 

 evening at the entrance of 

 its burrow, and stridulate 

 until a female approaches, when the louder . notes are 

 succeeded by a more subdued tone, while the success- 

 ful musician caresses with his antennne the mate he has 



-' L. Guilding, ' Transact. Linn. Soc' vol. xv. p. 154. 

 ^^ Kiippen, as quoted in the 'Zooloffical Record,' for 1867, p. 460. 

 " Gilbert White, 'Nat. Hist, of Selbornc,' vol. ii. 1825, p. 262. 

 " Harris, 'Insects of New England,' 1842, p. 128. 



Fig. 10.— Qryllus campestris (from Lan- 

 dois). 



Risht-hand floiire. under side of part of 

 the wing-nervuro, much maguifled, 

 showinn; the Iceth, st. 



Left-hand fitrure, upper surface of wing- 

 cover, with the projecting, smooth ner- 

 vure, r, across which the teeth {st) are 

 scraped. 



