The Value of a "Functional Test" in Selecting Material for a Genetic Study of Mammary Tumors in Mice and Rats

Abstract

It has been pointed out by Little, Strong, and others that one of the basic weaknesses of the early work in the experimental study of the genetics of neoplasms occurring in mice was that the animal strains used were not of sufficient purity. This objection was met by the long and tedious process of close inbreeding of various stocks coupled with careful tabulation of all tendency to the spontaneous development of neoplasms.