Chapter V: Section I: Insects undergoing Metamorphosis

1. _Coleoptera_ (from two Greek words signifying sheathed wings).
These are the beetles, which are all furnished with membranous
wings, with which they fly, and which are protected by horny upper
wings, or wing-cases, called elytra. They are all masticators, and
are all provided with mandibles or projecting jaws, and maxillæ.

2. _Orthoptera_, or straight-winged insects. This order comprises
the crickets, grasshoppers, locusts, and similar insects. They have
their upper wings of the consistence of parchment, and have
mandibles and maxillæ.

3. _Hemiptera_, or half-winged insects, have frequently half the
upper wing membranous, like the under ones, while the other half is
leathery. To this division belong the bugs, the water-scorpions,
the cicadæ or froghoppers, and the aphides. These insects have
neither mandibles nor maxillæ, but in their place have a sheath and
sucker.

4. _Neuroptera_, or nerved-winged insects, such as the
dragon-flies, have both pairs of wings membranous, naked, and
finely reticulated. The mouth is adapted for mastication, and
furnished with mandibles and maxillæ.

5. _Hymenoptera_, membranous winged insects, such as bees, wasps,
ichneumon flies, &c. All the four wings are membranous, but they
have fewer nervures, and are not reticulated like those of the
preceding order. The mouth is furnished with mandibles and maxillæ,
and the abdomen is terminated either by an ovipositor or a sting.

6. _Lepidoptera_, or scaly-winged insects. These are the
butterflies and moths, which are characterised by the farinaceous
or scaly aspect of their wings, and the tubular or thread-like
extension of the parts of the mouth.
7. _Strepsiptera_ or _Rhipiptera_, with twisted wings. These
creatures resemble the ichneumon, in laying their eggs in the
bodies of other insects, though they generally attack wasps and
bees. The principal genera are Xenos and Stylops. They are
generally considered to be closely allied to the Beetles.

8. _Diptera_, or two-winged insects, including the flies. The mouth
is furnished with a proboscis, and there are two small wings called
_halteres_ placed behind the true wings, which act as balancers.

9. _Suctoria_, or sucking insects, such as the flea, which have no
wings, but are furnished with an apparatus for sucking blood.