First published in 1986, this volume reviews the immune system of domestic ruminants, with particular emphasis on mechanisms of immunity and resistance to infectious diseases. Topics of comparative interest in other species are also covered. The cellular components of the immune system are discussed first, including ontogeny, structural organization and how they interact during the generation of immune responses. This is followed by information on specific aspects of humoral and cell-mediated immune responses, and finally a section on the relevance of various types of immune responses in protection against a number of important infectious diseases of ruminants. The papers included were presented originally at an international conference held in Nairobi, Kenya in September 1983. They provide authoritative coverage of a wide range of topics in ruminant immunology. Together, they comprise a valuable reference text for those involved in all aspects of immunological research in ruminants.