Abstract
The results of our experiments do not substantiate in full the theory of the power of selective action of Streptococcus viridans. A few strains showed a remarkable constancy in location and type of lesion, but these strains were greatly in the minority. The location of the lesions in animals seemed to bear no relation to the origin of the organism or to the lesions produced by it in the patient from which the strain was obtained. Streptococcus viridans, regardless of site of origin in the patient, produced most lesions in the heart and joints.