. 
272 CLASS VIII. 
Most Insects quit the eg¢ in a form entirely different from that 
which they afterwards possess. An impregnated female butterfly, 
for instance, deposits eggs, from which caterpillars proceed, which 
present not the slightest external resemblance with the mother. 
They are vermiform creeping animals, provided with different pairs 
of feet, which eat enormously, grow rapidly, cast their skin often, 
and at the last casting change into quite another creature, with a 
very hard and horny skin, which has no limbs, does not move from 
its place!, takes no food, and falls as into a death-sleep. There 
may however be generally discerned in the seemingly formless 
mass, on close observation, the external parts of the butterfly, 
which folded and rolled together are concealed beneath the horny 
shell, on whose surface they are traced out. After a longer or 
shorter time, sometimes only after many months, the perfect insect, 
the butterfly, quits its narrow cell. At first the wings are short, 
moist and unfit for flying, but soon unfold themselves, become dry, 
and then support the flapping Insect through the air, which soon 
fulfils its new destiny, the propagation of its kind, and dies?. 
In these changes of form (metamorphoses) of Insects the first 
form or first state is called that of the mask or larva, and the 
Insects are then named caterpillars, maggots, &c. The second state 
is that of nymph or pupa (in day-butterflies called also chrysalis). 
The third state is that of the perfect insect (insectum declaratum, 
amago). 
All Insects do not pass through this threefold state. The wing- 
less hexapod Insects, with few exceptions, leave the egg in the 
same form which they afterwards retain; only the rings and the 
feet become more numerous in the Myriapoda. ‘These Insects 
LATREILLE names Insects without metamorphosis. No winged 
Insect, on the other hand, comes from the egg with wings; but 
evolutione (De generatione Insectorum in ovo), Francof. ad Mcen. folio, Fasciculi 11. (not 
completed), relate principally to Musca vomitoria and some Lepidoptera, but do not 
give so much information as might have been expected from the diligent and patient 
investigations of the author. 
1 If the pupa be however in such a situation that the perfect insect would not be 
able to come out of it (in the branch of a tree, for instance), then it changes its place 
towards the period of the last change, by pushing on its body by contraction, a motion 
assisted in many cases by little hooks on the rings of the abdomen. 
? Sometimes the perfect insect, shortly after its coming forth, once more changes 
its coat, as is commonly known of the Ephemera. 
