Section III: Initiating Mechanisms and Early Pathogenesis.- 1 Gene Expression and Its Regulation.- 2 Developmental Genetics.- 3 Numerical and Structural Chromosome Abnormalities.- 4 Cell Death and Reduced Proliferative Rate.- 5 Altered Biosynthesis.- 6 Embryonic Intermediary Metabolism under Normal and Pathological Conditions.- 7 Altered Electrolyte and Fluid Balance.- 8 Abnormal Cellular and Tissue Interactions.- 9 Cell Morphogenetic Movements.- 10 Alterations in the Metabolism of Glycosaminoglycans and Collagen.- 11 Time-Position Relationships, with Particular Reference to Cleft Lip and Cleft Palate.- 12 Teratogenesis and Oncogenesis.- Section IV: Examples of Abnormal Organogenesis.- 13 Abnormal Organogenesis in the Eye.- 14 Abnormal Organogenesis in the Cardiovascular System.- 15 Abnormal Organogenesis in the Urinary Tract.- 16 Abnormal Organogenesis in the Reproductive System.- 17 Abnormal Organogenesis of Facial Structures.- 18 Abnormal Organogenesis in the Limbs.