Immunology is largely a science of observation and experimentation, and these approaches have lead to great increases in our knowledge of the genes, molecules and cells of the immune system. This book is an up-to-date discussion of the current state of modelling and theoretical work in immunology, of the impact of theory on experiment, and of future directions for theoretical research. Among the topics discussed are the function and evolution of the immune system, computer modelling of the humoral immune response and of idiotypic networks and idiotypic mimicry, T-cell memory, cryptic peptides, new views and models of AIDS and autoimmunity, and the shaping of the immune repertoire by early presented antigens and self immunoglobulin.