The Physiology of Insecta, Second Edition, Volume II, is part of a multivolume treatise that brings together the known facts, the controversial material, and the many still unsolved and unsettled problems of insect physiology. Since the first edition of this multivolume treatise was published, there has been a notable expansion of scientific endeavor in each of the various aspects of insect physiology. The original three-volume work has now grown to a thoroughly revised six-volume treatise. The book contains nine chapters that focus on the impact of environmental factors on the physiology of insects. The first chapter discusses the influence of temperature on insects, with attention to aspects likely to be of significance in relation to the rate at which individuals are born and die in natural populations. Separate chapters follow on the effects of humidity and radiation. Subsequent chapters deal with insect chemoreception and mechanorception; visual system, with a focus on compound eyes; sound production and the behavior associated with it; luminous insects; and the role of internal circadian oscillations in the life of insects with respect to the ""day"" outside, and on the role of the circadian system in biological time measurement.