I Differentiaton and Organization of Reproductive Processes.- 1 Sexual Organogenesis.- Body Sex.- Role of the Fetal Testis.- Dual Nature of the Testicular Chemical Signals.- Testicular Androgens.- M?llerian Inhibitor (or Anti-M?llerian Hormone).- Estrogen Production by the Fetal Ovary.- Gonadal Sex.- Testicular Organogenesis.- Ovarian Morphogenesis.- Control of Gonadal Differentiation.- References.- 2 Gonadal Hormones during Sexual Differentiation in Vertebrates.- Steroid Hormone Production in Developing Birds and Amphibia.- Morphology of the Embryonic Chick Testes.- Biosynthetic Capacity of Chick Gonads for Steroid Production.- Effects of Sex Steroids on Amphibian Development.- Steroid Production of Endocrine Tissues of Developing Amphibia.- Steroid Hormones in Developing Rodents.- Morphological Considerations.- Steroid Hormone Production by Fetal and Neonatal Gonads of Short-Gestation Rodents.- Steroid Hormone Production by Fetal Gonads in Long-Gestation Rodents.- Trophic Control of the Fetal Gonads in Rodents.- Functional Considerations of Fetal Rabbit Gonads.- Fetal Hormones of Domestic Animals.- Production of Steroid Hormones in Primate Fetuses.- Differentiation of the Fetal Testes.- Capacity of the Fetal Testes for Steroid Biosynthesis.- Androgens in the Systemic Circulation of Primate Fetuses.- Other Hormones and Sexual Differentiation.- Summary.- References.- 3 Nonmammalian Psychosexual Differentiation.- Psychosexual Differentiation in the Domestic Chicken (Gallus gallus).- Sex Differences and the Reproductive Behavior of Chickens.- Effects of Hormonal Manipulations before Hatching on the Behavior of Chickens.- Neurobiological Mechanisms of Psychosexual Differentiation in Domestic Fowl.- Psychosexual Differentiation in Japanese Quail (Coturnix coturnix japonica).- Sex Differences and the Reproductive Behavior of Quail.- Effects of Hormone Manipulations before Hatching on Reproductive Behavior.- Psychosexual Differentiation in Zebra Finches (Poephila guttata)lcä