General Immunology provides a general overview of the immune system. It presents topics in immunology from all living groups, treating cells, tissues, organs, and organismal levels of biological organization. The book contains 23 chapters organized into eight sections. Section I serves as an introduction to immunology—a science, a sketch of its history, some of its more recent contributors, something about gathering facts, immunology journals, and the entire biomedical enterprise of which immunology is just a part. Section II is devoted to antigens while Section III examines the immune system in chordates and the ontogeny of the immune system. Section IV on cells of the immune system covers monocytes, macrophages, the three granulocytic types, and mast cells. Section V deals with phagocytosis and the interaction of lymphocytes. Section VI is devoted to antigens in relation to antibody synthesis, antigen-antibody interactions, immunologlobulin structure, and immunologlobulin assembly. Section VII on organs of the immune system examines bone marrow, thymus, spleen, lymph nodes, and lymphoid aggregations. Section VIII discusses the evolution of the immune system. This text was written for advanced undergraduates. However, its comprehensiveness makes it useful to immunologists and biologists at all levels as well as medical students and clinicians.