THE METAMORPHOSIS OF INSECTS. 237 
said, ‘‘ Were a naturalist to announce to the world the 
discovery of an animal which for the first five years of 
its life existed in the form of a serpent; which then, pene- 
trating into the earth, and wearing a shroud of pure silk 
of the finest texture, contracted itself within this cover- 
ing into a body without external mouth or limbs, and re- 
sembling more than any thing else an Egyptian mummy ; 
and which, lastly, after remaining in this state for three 
years longer, should, at the end of that period, burst its 
cerements, struggle through its earthy covering, and 
start into day a winged bird, what would be the sensa- 
tion excited by this piece of intelligence?” And yet this 
would be no more wonderful than the ordinary metamor- 
phosis of Insects. Indeed, many of the most marvelous 
circumstances in this change are not at all referred to in 
the supposition above made. 
406. The larva is produced from an egg, and the egg 
is laid by the perfect Insect or Imago. When the larva 
is first hatched it is very small, but it grows with a ra- 
pidity always great, in some cases enormous. The mag- 
gots of flesh Flies are said to increase in weight two 
hundred times in twenty-four hours. To make such an 
increase these animals must eat voraciously. With the 
great multiplication of their number, the amount which 
a collection of them will sometimes devour is wonderful. 
Linneus calculated that three fiesh Flies and their imme- 
diate progeny would eat up the carcass of a horse sooner 
than a lion would do it. 
407. In the Imago state the Insect eats but little, as it 
grows little or none ordinarily. The Butterfly or Moth 
comes forth from its prison fully grown; but the cater- 
pillar from which it was formed was very small at the 
outset, and became large by large eating. Our common 
Flies are small and delicate eaters, but the Maggots, the 
larvee from which they came, rioting in filth, devour 
largely what the Flies will not touch. | 
408. The great growth of larve obliges them to east 
