Motility in a Species of Non-Flagellated Bacteria

Progressive gliding motility, lashing around a fixed pole, and flexion were found in five strains of Fusobacterium girans when examined in fluid suspensions by dark-field microscopy. Electron, phase contrast, and polarized light microscopy failed to reveal flagella on these organisms. The presence of a slime layer was indicated by electron microscopy, and by the use of India ink preparations. Motility apparently was not affected by the addition to the medium of either “Tween 80” or alkylated aryl sulphonate. Motility was inhibited in the presence of specific antiserum. No explanation is offered for the mechanism of motility in Fusobacterium girans.