Preface to the Progress Series; Preface to Volume X B; Contributors; Evolution of Steroid Hormones and Steroid-Hormone Receptors Gerd Käuser; Evolution of Developmental Peptide Hormones and Their Receptors Jozef Vanden Broack, Liliane Schoofs, and Arnold De Loof; Arthropoda-Insecta: Embryology August Dorn; Arthropoda-Insecta: Larval Development and Metamorphosis-Molecular Aspects Margarethe Spindler-Barth and Klaus-Deiter Spindler; Arthropoda-Insecta: Diapause David S. Saunders; Arthropoda-Insecta: Caste Differentiation Klaus Hartfelder; Arthropoda-Insecta: Endocrine Control of Phase Polymorphism August Dorn, Christof Ress, Silivia Sickold, and Silke Wedekind-Hirschberger; Arthropoda-Insecta: Migration Jack Kent Jr. and Mary Ann Rankin; Non-Veterbrate Chordata Mario Pestarino; Subject Index; Species Index.