How pure are our inbred strains of mice?

Abstract
Sixty-six individual tests on an array of skeletal variants showed an essential absence of parent-offspring correlations in the inbred strains C57BL, A and CBA in the mouse. It is concluded that these strains, and inbred strains of mice in general, are genetically homogeneous except for the differentiation of genetically distinct sublines as the result of mutations.