Zoogeographic studies can be pursued in the laboratory or library, but far preferably should be largely based on careful, first-hand field work. A familiarlty with species in the field is a prerequisite to a thorough understanding of both their zoogeography and their systematics. Naturally, knowledge of the actual relationships of the species, and of the geology and geographical history of the areas involved, are also prerequisites to a complete understanding of the zoogeography of a group of insects.