From mating #344 of rats purchased from a local breeder (Fischer). The colony was originated by M. R. Curtis, Columbia University in 1920. To the Germ-Free Animal Laboratory at CNRS, Gif-sur-Yvette, France from the Lobund Institute, University of Notre-Dame, South Bend, Indiana, U.S.A. Subsequently introduced to Charles River France in 1970 as an axenic colony.