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give more extension to this term, if we agree that all the noises 
(‘bruits’), that all the sounds (‘ sons ’), by means of which animals 
induce those of their species to perform certain actions deserve 
the name of voice, then we shall find as regards voice among insects 
and the organs of that of the Cigale, that they will be well worthy 
of our admiration.” 
Duges proposed the word " stridulation,” which has since 
become classical, to designate the sound caused by the vibration 
of solid plates ; but he reserved the name of u voice ” for that 
produced in a larynx by means of expired air. But in these 
days it has been fully demonstrated that in the act of phonation 
it is the vocal chords which form the vibrating body, while the 
current of air is simply the motor element ; the cavities of the 
pharynx and the thorax acting as a veritable sounding-box. All 
these elements, then, are to be found in the musical apparatus 
of the Cicada, the vibrating body being there represented by the 
“ timbales,” the motor agent by the muscles of the “ timbales,” 
and the sounding board by the cavities of the thorax and abdo- 
men. In both cases, then, it is a vibrating membrane which 
produces the sound ; the sole difference being in the fact that, 
on the one hand, this membrane is set in motion by a current of 
air, while, on the other, it is put in vibration by a motor muscle. 
From this it follows that there will be no incongruity in pre- 
serving the name song to indicate the vocal manifestations of 
the Cicada, although, scientifically speaking, the term stridula- 
tion would be preferable. In the neighbourhood of Grenoble 
the Cicadse usually sing from the season of the flowering of the 
vine until the second week in August.* The Cicada hcematodes 
is the first to appear, but does not sing much longer than the 
middle of July, when the C. plebeia begins to be heard, thus 
soon completely replacing the former. It is only during the 
day that the Cicada sings, and almost only during the sunshine 
— “ sole sub ardente,” as Virgil sang.f The large green grass- 
hopper, which is often erroneously taken for the Cicada, on the 
contrary, makes itself heard during the night ; and its zic, zic , 
* The parallel of the forty-fifth degree of North latitude, on which the 
town of Grenoble lies, is a northern limit which the Cicadse scarcely trans- 
gress in France. Nevertheless, they are to be heard a little, in all years, in 
the vineyards of Burgundy, and some specimens may even be taken in the 
neighbourhood of Fontainebleau. Pliny states that the voice of the Cicada 
is loudest at the solstices — ‘circa solstitium.’ — Nat. Hist. Lib. XI. 107. 
t “ The cicada is supposed by some to pipe only during mid-day, but 
both in Central America and Brazil I found them loudest toward sunset, 
keeping up their shrill music until it is taken up by night- vocal crickets 
and locusts.” — Belt, “The Naturalist in Nicaragua,” p. 312. London. 
1874. 
