Chap. X. 
HOMOPTERA. 
351 
in cages for the sake of their song, so that it must be 
pleasing to the ears of some men. 22 The Cicadidae 
usually sing during the day ; whilst the Fulgoridae 
appear to be night-songsters. The sound, according 
to Landois, 23 who has recently studied the subject, 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. It is increased by a wonderfully 
complex resounding apparatus, consisting of two cavi- 
ties covered by scales. Hence the sound may truly 
be called a voice. In the female the musical apparatus 
is present, but very 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, 24 “the drums are now (June 6th and 7th, 
“ 1851) heard in all directions. 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 larvae of Cic. pruinosa ; and I 
“ several times noticed the females to alight near a 
“ male while he was uttering his clanging notes.” Fritz 
Muller writes to me from S. Brazil that he has often 
listened to a musical contest between two or three 
males of a Cicada, having a particularly loud voice, and 
seated at a considerable distance from each other. As 
22 These particulars are taken from Westwood’s 6 Modern Class, of 
Insects,’ yol. ii. 1840, p. 422. See, also, on the Fulgoridse, Kirby and 
Spence, ‘ Introduct.’ vol. ii. p. 401. 
23 4 Zeitsehrift fur wissenschaft. Zcolog.’ B. xvii. 1867, s. 152-158. 
24 I am indebted to Mr. Walsh for having sent me this extract frcm 
a 4 Journal of the Doings of Cicada septemdecim,’ by Dr. Hartman. 
