what he called a methane bacillus which was used by Orla-Jensen (1909) as the type culture for the genus Methanomonas, and renamed as Methanomonas methantica. (Described in Bergey (1939)). Munz (1920) isolated and studied a somewhat similar methane-oxidizing organism which he classed as a facultative autotrope. St6rmer (1908) isolated an organism which he called Bacillus hexcarbovorum that was able to utilize toluene, xylol, and illuminating gas, in addition to methane, as a source of carbon. Organisms resembling Bacterium fluorescens, as described by Lehmann and Neuman (1896), capable of oxidizing methane completely to carbon dioxide and water, were isolated from rice swamp soils by Aiyer (1920). Sohngen (1913) reported that gasoline, kerosene, paraffin oil, and paraffin wax could be oxidized to carbon dioxide, water, and traces of organic acids by forms isolated from garden soil, ditch water and compost. The organisms studied by S6hngen belonged principally to the genera Mycobacterium and Pseudomonas. The following organisms were described and studied in this connection: Mycobacterium phlei, M. lacticola, M. album, M. luteum, M. rubrum, M. hyolinum, Bacterium fluorescers 661 The results indicate that the ability to utilize hydrocarbons is a common characteristic of this genus, particularly since known TABLE 2 Growth of stock cultures of Pseudomonas on mineral-8alts agar with kerosene