em to
entangle her prey, there are marks of evident design, for she adapts the
form of each net to its situation, and strengthens those lines, that
require it, by joining others to the middle of them, and attaching those
others to distant objects, with the same individual art, that is used by
mankind in supporting the masts and extending the sails of ships. This work
is executed with more mathematical exactness and ingenuity by the field
spiders, than by those in our houses, as their constructions are more
subjected to the injuries of dews and tempests.

Besides the ingenuity shewn by these little creatures in taking their prey,
the circumstance of their counterfeiting death, when they are put into
terror, is truly wonderful; and as soon as the object of terror is removed,
they recover and run away. Some beetles are also said to possess this piece
of hypocrisy.

The curious webs, or chords, constructed by some young caterpillars to
defend themselves from cold, or from insects of prey; and by silk-worms and
some other caterpillars, when they transmigrate into aureliae or larvae, have
deservedly excited the admiration of the inquisitive. But our ignorance of
their manner of life, and even of the number of their senses, totally
precludes us from understanding the means by which they acquire this
knowledge.

The care of the salmon in choosing a proper situation for her spawn, the
structure of the nests of birds, their patient incubation, and the art of
the cuckoo in depositing her egg in her neighbour's nursery, are instances
of great sagacity in those creatures: and yet they are much inferior to the
arts exerted by many of the insect tribes on similar occasions. The hairy
excrescences on briars, the oak apples, the blasted leaves of trees, and
the lumps on the backs of cows, are situations that are rather produced
than chosen by the mother insect for the convenience of her offspring. The
cells of bees, wasps, spiders, and of the various coralline insects,
equally astonish us, whether we attend to the materials or to the
architecture.

But the conduct of the ant, and of some species of the ichneumon fly in the
incubation of their eggs, is equal to any exertion of human science. The
ants many times in a day move their eggs nearer the surface of their
habitation, or deeper below it, as the heat of the weather varies; and in
colder days lie upon them in heaps for the purpose of incubation: if their
mansion is too dry, they