Pp. 2 -- Need for classification. pp .3 -- Studies on dissociation. pp. 6 -- Factors affecting the production of acetylmethylcarbinol. pp. 12 -- Storage of fat. pp. 18 -- Fermentation studies. pp. 20 -- Agglutination responses. pp. 24 -- Bacteriophagy. pp. 28 -- Methods and mediums. pp. 31 -- Key to species of the genus. pp. 35 -- Descriptions of species studies. pp. 39 -- Group 1. Sporangia not definitely swollen. pp. 39 -- Group 2. Sporangia definetly swollen by oval spores. pp. 78 -- Group 3. Sporangia swollen by round spores. pp. 94 -- Unclassified cultures. pp. 99 -- Literature cited. pp. 102 -- Index to measophilic members of the genus Bacillus. pp. 109.