From the examination of specimens
I have taken that had disfigured themselves, it appears that a moth
rubbed bare of down would seem as if covered with thinly cut, highly
polished horn, fastened together in divisions. This is called
`chitine' by scientists.
The thorax bears four wings, and six legs, each having five joints
and ending in tiny claws. The wings are many-veined membranous
sacs, covered with scales that are coloured according to species
and arranged to form characteristic family markings. They are a
framework usually of twelve hollow tubes or veins that are so
connected with the respiratory organs as to be pneumatic. These
tubes support double membranes covered above and below with down.
At the bases of the wings lie their nerves. The fore-wings each
have a heavy rib running from the base and gradually decreasing
to the tip. This is called the costa. Its purpose is to bear
the brunt of air-pressure in flight. On account of being compelled
to fly so much more than the females, the back wings of the males
of many species have developed a secondary rib that fits under
and supports the front, also causing both to work together with
the same impulse to flight.
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