THE SONG- OP THE CICADA. 
357 
zic quite differs from the stridulation of the Cicada, which can 
be represented sufficiently correctly thus : 
dz sss - - - s ssst* 
When the Cicada sings in a state of freedom, it keeps rapidly 
moving its abdomen, depressing and raising it in turns, so as to 
approximate or separate the operculcc (“volets ”) ; of which organs 
more anon. During this period the wings are motionless and 
applied close to the body. But if the insect be in captivity, in 
a cage for example, the abdomen does not habitually show any 
movements during the song. Lastly, if one holds a Cicada 
between the fingers, it violently vibrates its wings and sets in 
motion all the free part of its body, uttering piercing cries which 
sensibly differ from its ordinary song ; but soon the cries cease, 
and the wings droop immovable with fatigue. 
Before proceeding to describe the special structure of the 
sound-producing organs of the Cicada, it may be as well first to 
state, for the information of readers who are not zoologists, that 
all members of the group Insecta , to which the Cicada belongs, 
have the body primarily divided into “ head,” “ thorax,” and 
“ abdomen.” These parts are further differentiated into rings, 
segments, or “ somites,” f of which the head usually has six, 
fused together, the thorax consisting of three, distinct and fur- 
nished with limbs, while the abdomen is made up of from seven 
to eleven, usually nine, “ somites,” all limbless in the adult 
insect.^ In nearly all perfect insects each ring of the thorax carries 
on its under side two pairs of legs ; and on the sides of the two 
hindermost rings (the “ meso- ” and “ meta-thorax ”) two pairs 
of wings or their representative organs. Our attention, however, 
need only be specially directed to the last “somite” of the 
thorax and the first two of the abdomen in the Cicada. All 
descriptions hitherto given by authors of the musical organs of 
the Cicada are copied from Reaumur, and, inasmuch as they 
are incomplete and inexact, fail in clearness. The following 
description of them will be founded upon the record of the 
researches of M. Carlet, to which reference has been already 
made. 
* u Added to these noises were the songs of strange cicadas, one large hind 
perched high on the trees around our little haven, setting up a most piercing 
chirp ; it began with the usual harsh jarring tone of its tribe, but this 
gradually and rapidly became shriller until it ended in a long and loud note, 
resembling the steam-whistle of a locomotive engine.” — Bates, “The 
Naturalist on the River Amazon,” p. 230. 3rd edition. London. 1873. 
t From the Greek word crania, “ a body.” 
% The sole exception is a beetle ( Spirachtha eurymedusa), whose third, 
fourth, and fifth abdominal somites carry two-jointed limbs. — Vide Professor 
Macalister’s u Introduction to Animal Morphology,” . 386, Lond. 1876. 
