Diagnostic laboratory support for the management of a large colony of nonhuman primates will be provided. Complete necropsies will be done on all animals that die. This will allow early detection of conditions affecting colony health and provide a search for animal models of human diseases. Colony problems to be given particular attention are encephalitazoonosis in squirrel monkeys and immunosuppression among Macaca arctoides. A continuing search for naturally-occurring diabetes mellitus especially among M. fascicularis will continue.