References in classic literature ?
The increase of these flies, numerous as they are, must be habitually checked by some means, probably by birds.
What a struggle between the several kinds of trees must here have gone on during long centuries, each annually scattering its seeds by the thousand; what war between insect and insect--between insects, snails, and other animals with birds and beasts of prey--all striving to increase, and all feeding on each other or on the trees or their seeds and seedlings, or on the other plants which first clothed the ground and thus checked the growth of the trees
she repeated, and suddenly checked herself on the point of saying more.