negative strains according to the slide clumping reaction, were the test organisms. In the clumping factor-positive series, there were 13 coagoulase-positive (including the Smith strain) and three coagulase-negative organisms. The clumping factor-negative group was composed of eight coagulase-positive and six coagulase-negative staphylococci. Of the coagulase-positive, clumping factor-negative ...