On the Origin of European and North American Ants

Abstract

QUESTIONS belonging to zoogeography may be practical or theoretical, actual or genetic; ultimately the resolution of them, whatever they may be, takes its chief interest from their relations to genetical problems, that is, to the explanation of the origin of actual faunae, and to the knowledge of the original home of phyletic groups, and of the ways followed in their gradual diffusion over the whole or part of the world. To this purpose, not only living animals, but also fossils, have to be determined, and their affinities exactly worked out; changes in the distribution of land and sea and in the shape of continental areas must be investigated, and analogies and differences in the diffusion of various groups of living beings taken in consideration, as far as they are known. The work involved is long and difficult, and its results will form the science of the future.