Opening Remarks.- A. Theoretical Part.- Destruction of Complement-Target Cell Complexes by Mononuclear Leukocytes.- Discussion.- Anticomplementary Activity of Guinea Pig Serum Euglobulin: Its Relation to C 1 and to TAMe Esterase.- Discussion.- Experimental Inhibition of Complement.- Discussion.- Molecular and Stereochemical Properties Required of Antigens for the Elicitation of Allergic Reactions.- Discussion.- Mammalian Erythrocyte Receptors: Their Nature and Their Significance in Immunopathology.- Studies on the Structure and Formation of Antibodies.- Structure and Formation of Antibodies.- Discussion.- The Significance of the Carrier for the Induction of Antibodies.- Discussion.- The Effect of Cytostatic Agents on Nucleic Acid and Protein Synthesis and on Immunological and Non-Immunological Inflammation.- Discussion.- Studies on the Cytotoxicity of Lymphocytes.- Discussion.- Contact Sensitivity and Immunological Tolerance as Competitors in Sensitization to Simple Chemical Compounds.- Discussion.- Results of some Investigations on Lymphocyte Transformation in Vitro.- In-Vitro Stimulation of Lymphoid Cells by Antilymphocytic Globulins.- Discussion.- The In Vitro Transformation of Lymphocytes of Premature and Mature Infants.- Cell-Bound Antibodies to Streptococcal Cell-Wall Preparations.- Discussion.- Delayed Hypersensitivity and Tumor Specific Immunity.- Discussion.- Histological Changes in NZB/NZW Mice.- Discussion.- B. Clinical Part.- Clinical and Serological Aspects of the Aetiologic Differentiation of Auto-Immune Haemolytic Anaemias.- Discussion.- The Pathogenesis of Hemolytic Diseases of the ABO-System of the Newborn.- Discussion.- Immune Phenomena in Pernicious Anaemia.- Discussion.- Immune Reactions in Chronic Liver Diseases.- Discussion.- Cellular Immune Reactions in Experimental Hepatitis.- Quantitative Serum Immunoglobulin Determinations in Active Chronic Hepatitis and Idiopathic Cirrhosis.- Discussion.- The Possible Role of Lipid-Containing RNA Viruses for the Ethiology of Autoimmune Diseases.- Discussion.- Humoral Antibodies in Older Humans.- Discussion.- Experimental Glomerulonephritis in Unresponsive Rabbits after Termination of Immunologic Tolerance.- Discussion.- The Long Acting Thyroid Stimulator (LATS) in Thyrotoxicosis.- Discussion.- Immunological Investigations in Myasthenia Gravis and other Skeletal Muscle Disorders.- Discussion.- Comparative Studies of the Immunopathology of Inflammatory Cardiovascular Diseases.- Discussion.- Possible Bithermic Pathomechanism in Cryoglobulinemic Vasculitis.- Discussion.- Amyloid Involvement and Monoclonal Immunoglobulins.- Discussion.- Research in Drug Allergy: A Search for Impurities ?.- Discussion.- Immunogenicity of Semisynthetic Penicillins.- Discussion.- Author Index.