SOUNDS MADE BY INSECTS. 
7 
tions, more by their odor than by their visible characters. But no organ 
ot smelling has been discovered, and this sense is supposed, from anal- 
ogy, to be located in the lining membranes of the spiracles. 
T( iste and Touch .— It is impossible to determine, but there is no reason 
to doubt, that' insects, like other animals, taste and enjoy the food of 
which they partake ; and the manner in which they frequently touch 
their iood, and the surfaces over which they walk, with the tips of their 
palpi, which, indeed, have received the common name of feelers, renders 
it probable that these organs are endowed with a special sense of touch. 
SOUNDS PRODUCED BY INSECTS. 
The songs of birds, and the noises made by other animals, are pro- 
duced by the forcible passage of air through the glottis, which is the 
narrow opening at the top of the wind pipe, aided by the vibration of ' 
certain muscular folds near the outlet, called the vocal chords. But we 
have seen that insects never breathe through their mouths, and there- 
fore they never make any oral sounds. But the humming of bees and 
Hies is produced in an analogous manner, by the expulsion of air through 
the thoracic spiracles, and the vibration of a delicate valve-like ford 
just within the opening. 
But besides this, insects make a variety of noises, which are produced 
in different ways. The singing of the Cicada, which is the loudest noise 
made by any insect, is produced by the expulsion of air from the first 
abdominal spiracle, striking upon a large transparent drum-like appa- 
ratus, situated at the base of the abdomen. The chirping of crickets is 
produced by rubbing together their parcliment-like wing covers. The 
well-known noise of the katy-did is produced in the same way, but here 
the sound is intensified by a thin talc-like plate set into the base of each 
wing-cover. The stridulation of grasshoppers is caused by the friction 
ot their spined shanks across the edge of their wing-covers. The 
fainter, squeaking sounds, made by mauy insects when captured are 
produced simply by the rapid friction of one part of their bodies upon 
another; in certain Hemiptera, by the friction of the head upon the pro- 
thorax ; in the Capricorn beetles, by the friction of the pro-thorax upon 
the meso-thorax; and in some of the Lamellicoru beetles, by the friction 
of the abdomen against the wing covers. 
The more complex and special apparatuses of insects for the produc- 
tion of sounds, are possessed exclusively by the males, and are supposed 
to be exercised by them as calls to the opposite sex; but the simpler 
squeaking sounds are emitted by both sexes, and appear to bo mere 
notes of alarm. 
