THE CATERPILLAR. 
i03 
other insects ; they neither follow the opposite sex, nor bear 
any enmity to each other : after fluttering for an hour or two, 
they drop upon land, without seeming to receive wiims for 
any other purpose but to satisfy an idle curiosity. It is 
otherwise with the females ; they are scarce risen from the 
surface of the water, and have dried their wings, but they 
hasten to drop their eggs back again. If they happen also 
to flutter upon land, they deposit their burden in the place 
where they drop. 
Of all insects, this appears to be the most prolific; and it 
would seem that there was a necessity for such a supply, as, 
in its reptile state, it is the favourite food of every kind of 
fresh-water fish. It is in vain that these little animals form 
galleries at the bottom of the river, whence they seldom re- 
move; many kinds offish break in upon their retreats, and 
thin their numbers. For this reason, fishermen are careful 
to provide themselves with these insects, as the most grateful 
bait ; and thus turn the fish’s rapacity to its own destruction. 
But though the usual date of these flies is two or three 
hours at farthest, there are some kinds that live several days; 
und one kind in particular, after quitting the water, has ano- 
ther case or skin to get rid of. These are often seen in the 
fields and woods, distant from the water ; but they are more 
frequently found in its vicinity. They are often found 
sticking upon walls and trees; and frequently with the head 
downwards, without changing place, or having any sensible 
potion. They are then waiting for the moment when they 
shall be divested of their last incommodious garment, which 
sometimes does not happen for two or three days together. 
CHAP. XXXVII. 
Of Insects of the Third Order— Caterpillars — Change 
to the Aurelia — To the Butterfly — Moths — Singular 
Cause for the Destruction of Caterpillars — The Silk- 
worm — Mode of rearing it — Its changes. 
Caterpillars may be easily distinguished from worms 
or maggots by the number of their feet ; and by their pro- 
ducing butterflies or moths. When the sun calls up vegeia- 
l| on, and vivifies the various eggs of insects, the cateipillars 
are the first that are seen, upon almost every vegetable and 
