1. The hemophilic bacilli can be divided into two large groups according to the ability of certain strains to produce hemolysis.
2. Both the hemolytic and the non-hemolytic groups may be further subdivided according to the ability of some strains to produce indole, to form gas, and to ferment certain carbohydrates.
3. The hemophilic bacilli of both the hemolytic and the non-hemolytic varieties when grown in meat infusion broth containing 1 per cent of dextrose reach a final hydrogen ion concentration of about pH 6.4. In addition, practically all the strains possess the power to reduce nitrates to nitrites.