GENERATION OF INSECTS. The world is now generally convinced, that insects are not bred of corruption, but ex ovo; though the contrary was believed by the ancients, because of the vast numbers that were sometimes hatched, as it were at once, and because they could not discern the particular manner of their propagation.
Malpighi, Swammerdam, and Redi, have abundantly disproved the doctrine of equivocal generation, as well as the chimerical transformation of the caterpillar into the butterfly, and other the like metamorphoses; and have shown, that all the members of the butterfly were originally inclosed under the skin or nymph of the caterpillar, as the parts of a plant are in the seed.
Insects take particular care to deposit their eggs or feed in such places where they may have a sufficient incubation, and where the young, when hatched, may have the benefit of proper food till they become able to shift for themselves. Those whose food is in the water, lay their eggs in the water; those to whom flesh is a proper food, in flesh; and those to whom the fruits or leaves of vegetables are food, are accordingly deposited, some in this fruit, some in that tree, and some in one plant, and some in another; but constantly the same kind in the same tree or plant. As for others that require a more constant and greater degree of warmth, they are provided by the parent animal with some place in or about the body of other animals; some in the feathers of birds, some in the hair of beasts; some in the scales of fishes, some in the nose, some in the flesh, nay, some in the bowels and inmost recesses of man and other creatures. And as for others, to whom none of those methods are proper, the parents make them nests by perforation in the earth, in woods, in combs, and the like; carrying in and sealing up provisions that serve both for the production of their young, and for their food, when produced. In flies, butterflies, &c. it is observed, there is a kind of gluten, by which the female fastens her eggs to the bearing buds of trees, &c. so that the rains cannot wash them off. These eggs will not be hurt by the greatest frost.