The plover comes in place of the grouse; the partridge in place of the plover; and where coppices become abundant, the pheasant, in turn, invades the dominion of the partridge.

The trees and plants, with more succulent leaves, that cul- tivation introduces instead of the heath, the hard grass, the furze, the broom, and all those native vegetables of the north that have austere juices, necessarily bring along with them a vast number of insects.

We say necessarily; for wherever the proper food for any of the productions of nature is to be found, thither will that production come to it, by means that no one can find out : as, for instance, if roses or cherries are intro- duced, there are sure to be aphides ; if any of the brassicas, there are sure to be caterpillars ; and, if there be even an introduction of nettles, their beautiful butterflies will visit them.

When they have increased to a certain amount, they are sure to bring not only those resident birds that feed them- selves and their young upon larvae, but also the warblers and other summer visitants.

" These remarks we can verify by similar instances, which have come within our own experience.