This order of insects is known popularly by the names of Butterfly and
Moth. Linnæus gave them the name of _Lepidoptera_, meaning insects
with scaly wings ([Greek: lepis], a scale; and [Greek: pteron], a
wing). They are to be found in great numbers in all parts of the
world. All the insects contained in the order are, in their perfect
state, remarkable for the elegance of their shape, the rapidity and
airiness of their flight, and the multiplicity and beauty of their
colours. Before they arrive at this perfect state, the Lepidoptera
have to undergo three complete transformations. They leave the egg in
the larva or caterpillar state; they pass next to the state of pupa,
or chrysalis; they then assume, after a variable time, their final or
perfect form. We will study them in their three different states in
succession.