Abstract
A numerical classification using fifty-two characters was done on 72 strains of mycobacteria, including Mycobacterium avium, M. terrae, the pathogenic nonphotochromogens and the pathogenic scotochromogens. The results indicated that the test strains could be divided into two subgroups, the first consisting of M. avium and M. terrae and the second of the nonphotochromogens and the scotochromogens. Distinguishing characters for differentiation between these organisms were described, and taxonomic position of these organisms was discussed.
