Book excerpt: Fundamental research on sheep and cows has often provided answers to significant questions, not only for investigators of the gastrointestinal tract of ruminant and other species, but also for workers in practical areas such as world food supplies, animal husbandry, and medical practice. This book is an interdisciplinary survey of some of the most recent advances in ruminant research, especially on comparative aspects of the digestive tract. Fourteen articles by an international group of leading scientists cover a wide range of topics: comparative anatomy related to digestive function; microbial ecology; pathophysiology; neurophysiology; endocrinology; ionic transport; energy, intermediary, and mineral metabolism; and differential rate of flow of digesta.