This volume details the origins and history of insect endocrinology, from its remarkably intuitive beginnings, through the occasionally circuitous, but ultimately successful, investigations by several generations of endocrinologists who have progressively transformed the field to one characterized by vigor, enthusiasm, and scientific excellence. From the opening chapter by the founder of the field, Sir Vincent Wigglesworth, documenting the origins of this science, to the chapter defining the new investigative area of comparative vertebrate-invertebrate endocrinology, this volume, augmented by volume 8 of this series, presents the evolution of insect endocrinology up to the most recent discoveries with a level of detail that makes it an unsurpassed resource for today's endocrinologist.