ORGANS OF INSECTS DESCRIBED. 
7 
spots ; and grubs, after their first transformation, are often 
named nymphs, for what reason does not appear. At the 
end of the second period, insects again shed their skins, and 
come forth fully grown, and (with few exceptions) provided 
with wings. Thus they enter upon their last or adult state, 
wherein they no longer increase in size, and during which 
they provide for a continuation of their kind. This period 
usually lasts only a short time, for most insects die imme- 
diately after their eggs are laid. Bees, wasps, and ants, 
however, which live in society, and labor together for the 
common good of their communities, continue much longer 
in the adult state. 
In winged or adult insects, two of the transverse incisions 
witli which they are marked are deeper than the rest, so that 
the body seems to consist of three principal portions, the first 
whereof is the head, the second or middle portion the thorax, 
or chest, and the third or hindmost the abdomen, or hind- 
body. In some wingless insects these three portions are also 
to he seen ; hut in most young insects, or larvae, the body 
consists of the head and a series of twelve rings or segments, 
the thorax not being distinctly separated from the hinder part 
of the body, as may he perceived in caterpillars, grubs, and 
maggots. 
The eyes of adult insects, though apparently two in num- 
ber, are compound, each consisting of a great number .of 
single eyes closely united together, and incapable of being 
rolled in their sockets. Such also are the eyes of the larvae, 
and of the active pupae of those insects that undergo an 
imperfect transformation. Moreover, many winged insects 
have one, two, or three little single eyes, placed near each 
other on the crown of the head, and called ocelli , or eyelets. 
The eyes of grubs, caterpillars, and of other complete ly trans- 
forming larvae, are not compound, but consist of five or six 
eyelets clustered together, without touching, on each side of 
the head ; some, however, such as maggots, are totally blind. 
Near to the eyes are two jointed members, named antenuce. 
