During the years that have intervened since the third volume of the International Life Sciences Institute (ILSI) Monographs on Pathology of Laboratory Animals, Digestive System, was published, new information of interest to pathologists has developed at a rather remarkable pace. Standardized nomenclature has been proposed and gained significant acceptance during the period since the first edition and is being utilized on an international basis. This has resulted in improvement in communi cation of pathologic data to regulatory agencies and in scientific publica tions worldwide. This monograph...