Page:Bergey's manual of determinative bacteriology.djvu/283

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FAMILY VII. SPIRILLACEAE
261

When the gelatinous mass disintegrates, swarm cells are formed which are pre- sumably polar flagellate. The individual cells are granular and stain rather poorly. During reproduction, the filaments be- come somewhat elongated and expand the gelatinous mass to an ellipsoidal shape. As the gelatinous sphere undergoes transverse fission, there is a concomitant division of the filament, the daughter cells finally separat- ing from each other. Lankester (Quart. Jour. Micros. Sci., 13, (N.S.), 1873, 408) erroneously believed this gelatinous form to be a stage in the life cycle of a Spii-ilhim, probably Spirillum undula Ehrenberg. These organisms have not been cultivated on artificial media. Source : Found in the surface scum of sul- fur-water in a jar with decomposing algae, especially Spirogyra sp. (Cohn, op. cit., 1875, 183). Also found by Migula {op. cit., 1900, 960) in peat bogs between Weingarten and Karlsruhe. Hansgirg (Osterr. Vot. Ztschr., 38, 1888, 265) frequently found this organism among his algal cultures in Bo- hemia. Habitat: Fresh-water ponds.