An introductory guide to modem dragonfly wing venation is presented. Some remarks are made on tracheation, and on the venational nomenclature of the theory of pre-tracheation. The wings of fossil dragonflies are then considered. The meganeurids, the Protozygoptera, the Protanisoptera, the Liassic Anisozygoptera, and the Jurassic and Tertiary fossils are discussed in turn. Finally the primitive and specialized features of venation are considered.