40 
ELEMENTS OF ENTOMOLOGY. 
Of the LARVA, or Caterpillar state. All caterpillars are hatched 
from the egg, and when they first proceed from it are generally small 
and feeble, but grow in strength as they increase in size. The body of 
the caterpillar consists of twelve rings; the head is connected with the 
first, and is hard and crustaceous. N o caterpillar of the moth or butterfly 
has less than eight, or more t han sixteen, feet; those which have more 
than sixteen belong to some other order of insects. The six anterior 
feet, or those next the head, are hard and scaly, pointed and fixed to 
the first three rings of the body, and are in number and texture the 
same in all Lepidopterous larva*. The posterior feet are soft, flexible, or 
membranaceous; they vary both in figure and number, and are observa- 
ble only in the caterpillar state, the perfect insect having only six feet, 
the rudiments of which are the six anterior scaly feet before mentioned. 
These spurious feet are either smooth or hairy, soft to the touch, or 
hard like shagreen. On each side of the body arc nine small oval 
apertures, which are the spiracles or organs of respiration. 
The caterpillar, whose life is one continued succession of changes, 
often moults its skin before it attains its full growth. These changes are 
the more singular, because when it moults it is not simply the skin that 
is changed; for we find in the exuviae the jaws, and all the exterior parts, 
both scaly and membranaceous. 
1 he change in tne caterpi I lar is effected by the creature’s withdrawing 
itself from the outer skin as from a sheath, when it finds itself incom- 
moded from being confined withina narrow compass. Out to accomplish 
this change is the work of sonic labour and time. Those caterpillars 
which Live in society, and have a nest or habitation, retire there to change 
their skin, fixing the hooks of the feet, during the operation, firmly* in 
the web of their nest. Some of the solitary species spin at this time a 
slender web, to which they affix themselves. A day or two before tire 
critical moment approaches, the insect ceases to eat, and loses its usual 
activity ; in proportion as the time of its change approaches, the colour 
of the caterpillar delines in vigour, the skin hardens and becomes 
withered, and is soon incapable of receiving those circulating juices by 
which it was heretofoie nourished and supported. The insect is now 
seen at intervals with its back elevated, or with the body stretched to 
the utmost extent; sometimes raising its head, moving it from one side 
to another, and then letting it fall again. Near the change the second 
and third rings arc seen considerably swollen. By these" internal ef- 
forts the old parts are stretched and distended as much as possible, an 
operation attended with difficulty, as the new parts arc all weak and 
tender. However, by repeated exertions, all the vessels which con- 
veyed nourishment to the exterior skin are disengaged, and cease to 
act, and a slit is made on the back, generally beginning at the second 
or third ring. The new skin may now be just perceived, being distin- 
guished by its freshness and brightness of colour. The caterpillar then 
