ARTICULATA. 133 
(pl. 81, figs. 18, 28, 438, &e.). The inaccuracy of this will appear, upon 
reflecting that the thorax in the Hymenoptera bears the wings and all the 
feet, whilat the segment next to the head in the Coleoptera tithtra the anterior 
pair of feet alone, “corresponding only to one third the thorax of the former. 
In the Coleoptera, the elytra or wing-covers, when in a state of repose, 
generally cover the abdomen and two thirds of the thorax, keeping the 
latter out of view when the insect is viewed from above. A lateral or 
ventral view (pl. 81, figs. 105, 106, 180) will exhibit the remaining parts 
of the thorax bearing the*wings and the medial and posterior feet. In some 
cases the abdomen is entirely exposed, the elytra being so short as not to 
extend beyond the thorax (pl. 81, figs. 1-7). The three segments which 
comprise the thorax both of a hymenopter and a coleopter, may be recog- 
nised by the three pairs of feet; but whilst that next to the head (named 
the prothorax) is conspicuous in the latter, it is reduced to a mere collar in 
the hymenopter, where the next segment or mesothorax is largely developed, 
to bear the large anterior pair of wings, whilst the corresponding part in 
the Coleoptera have to bear the elytra, which are not used as organs of 
flight. Finally, the metathorax, or third segment of the thorax, is reduced 
in the Hymenoptera, the wings of this segment being small and of but 
secondary importance in flight, whilst in the Ccleoptera the same organs 
are the only instruments of flight. 
Most insects are oviparous; some, as Uusca carnaria, are ovo-viviparous, 
the eggs being hatched aren the body, and in the Baveaes the young 
advances to the pupa state before it is excluded, the apparent egg-shell being 
the pupa case. 
The egg of insects is generally oval, but there are many other forms, as 
globular, hemispherical, cylindrical, lenticular, conical, pyriform, &c. The 
egos of Hemerobius are attached to leaves at the extremity of a long thread. 
Some are crowned at one extremity, and others have ear-like appendages. 
In most cases the surface is smooth, but they sometimes occur ribbed or 
sculptured in various patterns. White, yellow, and green, are almost the 
only colors observed in them. The eggs of insects are deposited according 
to the wants of the young to which they are to give birth, either in earth, 
water, dung, upon dead animals, or in putrid vegetables, beneath the skin 
of caterpillars, in punctures in living vegetables, where they sometimes 
cause galls; some are glued to leaves or branches, and others are placed in 
cells where the young are fed. 
The darva appears when the shell of the egg is burst at the period of its 
inaturity. ‘The name larva is applicable to the young of all insects, although 
those of butterflies are also named caterpillars, and those of certain flies 
maggots. ‘The larva is in most cases unlike the adult insect, generally 
appearing as a cylindrical worm, either without feet or with six or more 
walking organs, of which six only are articulated feet. In this condition 
nourishment is taken, often in great quantities; the growth is rapid, and a 
series of moultings is undergone. When the larva has attained its full size, 
im many cases it becomes an inactive pupa without external organs, and 
incapable of locomotion or taking food; but when the pupa case is burst, the 
ICONOGRAPHIC ENCYCLOP£DIA.—VOL. II, 22 337 
