The first edition of this book was published in 1930. The new material developed in the past ten years makes a new edition necessary. The chapters on animal parasites, on fungous diseases and on psittacosis have been entirely rewritten and new chapters have been added on louping ill, sore mouth in sheep, equine encephalomyelitis, Rift Valley fever, typhus fever and relapsing fever. In the development of this book, Dr. Hull has called on a large list of competent consultants who have been giving special attention to the subjects discussed. The book is a handsome production, quite up to date, and scientifically dependable.