Relationships among colonies of the laboratory rat

Abstract
Morphometrical analysis of the shape of the mandible of the rat was carried od on 88 samples of rats com 41 separate colonies. Outbred Wlstar and Sprague bawley rats in the United Kingdom are shown to be heterogeneous with substantial overtsp between the two types. Inbred strains have distinct shapes that are unlike he outbred stocks they are supposed to be derived from. The shape of the rat's mandible can now be used for henetically monitoring colonies of rats as well as nice.