At the outset it seems desirable to emphasize the view that ecology is not a new division of biology, or indeed a division at all. It is merely a point of view, a new method of attack, which has been as natural a rebound from the intensive laboratory research of the last twenty-five years as this was a logical reaction from the more diffusive studies of natural history. The viewpoint of ecology inheres in the “oikos,” or habitat, as the motive force in the life processes of plants and animals, both as individuals and as communities. As a consequence of this vital relation ecology is essentially synthetic. It is deeply concerned with soil and climate, but never as ends in themselves, merely as intrinsic parts of basic biological processes. While the ecologist can not ignore the static forms of plant and animal life, he is interested in them chiefly as . . .