Laboratory Animal Medicine has made enor We deeply appreciate the efforts of each of the mous strides in the 47 years since R. Jaffe published authors and co-authors of the 23 chapters in this his "Anatomy and Pathology of Spontaneous Dis two volume work. In some instances the reader will eases of Small Laboratory Animals" in 1931. So note what appears to be repetition in certain chap ters. This repetition was allowed to stand in some much new information had accumulated that in a cases because different approaches seemed useful, new edition in 1958, Jaffe, aided by Cohrs and Meessen, needed the assistance of 46 colleagues to although efforts were made to delete most of the do the subject justice. Like its predecessor, this two redundancy which inevitably arises in a venture of volume comprehensive treatise on "Pathologie der this kind. We will be grateful if our colleagues point out errors and send us specific and general Laboratoriumstiere" was written in German and criticism of this work to allow corrections in the thus not readily available to the widening circle of event of reprinting or a next edition. veterinarians and pathologists who now are inter One objective has been to assemble current in ested in laboratory animals. Aside from the need to have a comprehensive formation in the pathologic aspects of diseases of review of laboratory animal pathology in English, laboratory animals.