Musical Insects, 



461 



with in detail : we can only |)ick out a few rei)resentative species and describe 

 the nature of their sounds and how these are produ.ced. 



The Insect most celebrated for its sonp; from anti(|uitv is the cicada, concern- 

 ing; which the Greek y)oet Xenarchus wrote the ungallant couplet that has been 

 (]uoted almost (/(/ iinnseajn, possibly ever since it \\as written — 



Happy the cicadas' lives, 

 I^^or the\' all ha\'e voiceless wi\'es." 



The cicada stands apart from all other Insects, indeed from all other animals, 

 in the character of its musical instrunnnt. It is not here a case of scrapini,' one file 

 on another, or a file on a drum. There is a special ca\'itv in the trunk, divided 

 into chambers by films of different character, and a specially delicate drum or 

 tymbal, which is set vibrating by the Insect to produce the initial sound. These 

 vibrations are caught up and in- • 

 tensified bv the other membranes 

 and the two shields which cover 

 the entire apparatus on the under 

 surface of the Insect. There is a 

 special muscle which sets the tvmbal 

 \'ibrating, and these \-ibrations can 

 be watched when the Insect is 

 singing. Respecting the silence of 

 the females, which attracted the 

 attention of Xenarchus, it is not 

 due to want of the apparatus, but 

 to the fact that it is not fully 

 developed. Hartman speaks of the 

 music as the " marital ^lm^m()ns 

 from the males." 



Speaking of the sounds pro- 

 duced b\' American cicadas, Darwin 

 says that when the Beagle was 

 anchored at the distance of a 

 quarter of a mile from the shores 

 of Brazil, " the noi-^e thus made 

 could be plainh' heard on board 

 allude to it a 

 by a remark 



he was in the same region. Desciibing the " terrible discord " of mingled 

 noises set up at sunset bv birds and monkeys, the latter naturalist sa\-s : 

 " Added to these noises were the >()rigs of strange cicadas, one large kind ])erclu^d 

 high on the trees around ovu" little ha\en setting up a most piercing chirp ; it began 

 with the usual harsh, jarring iouc of its tribe, but this graduall\- and rapidly became 

 shriller, until it ended in a long and loud note resembling the steam-whistle of a 

 locomoti\'e (,'ngine. Half a dozen of these wonderful performers made a consider- 

 able item in the exeninu concert." 



Pholo by] 



CiCAD.\'s ■■ Drum." 



[H. B:islill. 



rill- 'ihicM on tho right side of a male cicada has been turned aside to 

 11 veal the nmsciilar "drum," which is set vibrating to produce the initial 

 MUinds. 'I'he X'ibrations are caught n]) and iiitiii<iMefl bv other portions 

 "1 tile apii.nalii--. 



It will be noted that Darwin does not 

 a musical sound, but a noise, and in this he i-^ jierhaps justified 

 )f Jjates, who was i)robably relerring to the same species, for 



