Abstract
Of 126 strains of hemolytic streptococci, 90 of animal and 36 of human origin, the animal cultures produced a higher acidity in glucose broth than did the human. 94% of animal strains could be differentiated from human cultures by the fact that they produce acid from sorbitol and fail to ferment trehalose. Streptococci of human origin all fermented tre-halose and failed to attack sorbitol.