HBMIPTBRA AND IIOMOPTERA. 279 



the case of Pirates stridulus, this is said'-- to be effected by tbe 

 movement of the neck within the pro-thoracic cavity. Accord- 

 ing to Westring, Reduvius personatus also stridulates. But I 

 have no reason to suppose that this is a sexual character, except- 

 ing that with non-social insects there seems to be no use for 

 sound-producing organs, unless it be as a sexual call. 



Order, Homoptera.' — Every one who has wandered in a tropical 

 forest must have been astonished at the din made by the male 

 Cicadse. The females are mute; as the Grecian poet Xenarchus 

 says, "Happy the Cicadas live, since they all .have voiceless 

 "wives." The noise thus made could be plainly heard on board 

 the "Beagle," when anchored at a quarter of a mile from the 

 shore of Brazil; and Captain Hancock says it can be heard at the 

 distance of a mile. The Greeks formerly kept, and the Chinese 

 now keep these insects in cages for the sake of their song, so that 

 it must be pleasing to the ears of some men.-^ The Cicadidse 

 usually sing during the day, whilst the Fulgoridae appear to be 

 night-songsters. The sound, according to Landois,^* is produced 

 by the vibration of the lips of the spiracles, which are set into 

 motion by a current of air emitted from the tracheae but this view 

 has lately been disputed. Dr. Powell appears to have proved^' 

 that it is produced by the vibration of a membrane, set into ac- 

 tion by a special muscle. In the living insect, whilst stridulat- 

 ing, this membrane can be seen to vibrate; and in the dead in- 

 sect the proper sound is heard, if the muscle, when' a little dried 

 and hardened, is pulled with the point of a pin. In the female 

 the whole complex musical apparatus is present, but is much less 

 developed than in the male, and is never used for producing 

 sound. 



With respect to the object of the music. Dr. Hartman, in 

 speaking of the Cicada septemdecim of the United States, says,^'' 

 "the drums are now (June 6th and 7th, 1851) heard in all di- 

 "rections. This I believe to be the marital summons from the 

 "males. Standing in thick chestnut sprouts about as high as my 

 "head, where hundreds were around me, I observed the females 

 "coming around the drumming males." He adds, "this season 

 "(Aug. 1868) a dwarf pear-tree in my garden produced about fifty 

 "larvffi of Cic. pruinosa; and I several times noticed the females 



22 Westwood, 'Modern Class, of Insects,' vol. ii. p. 473. 



^ These particulars are taken from Westwood's 'Modern Class, of 

 Insects,' vol. ii. ISIO, p. 422. See, also, on the Fulgoridae, Kirby and 

 Spence, 'Introduct.' vol. ii. p. 401. 



24 'Zeitschrift fur wissenschaft Zoolog.' B. xvii. 1867, s. 152-158. 



== 'Transact. New Zealand Institute,' vol. v. 1873, p. 286. 



2« I am indebted to Mr. Walsh for having sent me this extract from 

 a. 'Journal of the Doings of Cicada septemdecim,' by Dr. Hartman. 



