FAMILY VII. SPIRILLACEAE 



253 



3. Cellfalcicula fusca Winogradsky, 

 1929. (Ann. Inst. Pasteur, A3, 1929, 622.) 



fus'ca. L. adj. fuscus dark, tawny. 



Plump, curved spindles, 0.5 by 1.2 to 2.5 

 microns, with slightly pointed ends and a 

 central chromatic granule. Motile by means 

 of a single, polar flagellum. Gram-negative. 



Produces diffuse, brownish, slightly 

 marbled or veined colonies on cellulose silica 

 gel medium. 



Filter paper streak: Paper becomes a 

 partially transparent, dry, non-mucilagi- 

 nous pellicle adherent to gel. 



Aerobic, facultative. 



Optimum temperature, 20° C. 



Source: Isolated from a pile of old, damp 

 sawdust. 



Habitat: Probably rotting wood. 

 Genus VI. Microcyclus 0rskov, 1928.* 



(Cent. f. Bakt., I Abt., Orig., 107, 1928, 180; also see Riassunti d. Communicazioni, 

 VI Cong. Internaz. d. Microbiol., Roma, 1, 1953, 24.) 



Micro. cyc'lus. Gr. adj. micrus small, little; Gr. cyclus round, circle; M.L. mas.n. Mic- 

 rocyclus small circle. 



Small, slightly curved, non-motile rods which form a closed ring during growth. These 

 rings grow into bodies which subdivide again into rod-shaped elements as at the beginning. 

 Encapsulated. Attack few sugars and then only slowly. From fresh-water ponds and from 

 soil. 



The type species is Microcyclus aquaticus ^rskov. 



1. Microcyclus aquaticus 0rskov, 1928. 

 (Cent. f. Bakt., I Abt., Orig., 107, 1928, 180; 

 also see Riassunti d. Communicazioni, VI 

 Cong. Internaz. d. Microbiol., Roma, 1, 

 1953, 24.) 



a.qua'ti.cus. L. adj. aquaticus living in 

 water. 



Very small, slightly curved rods about 1 

 micron in length. During growth, the rods 

 form closed rings 2 to 3 microns in diameter. 

 The next stage is a body consisting of horse- 

 shoe-shaped halves that are fastened to- 

 gether without visible divisional lines. 

 These halves further subdivide into separate 

 rods ; the rods then form rings and start the 

 cycle of growth all over again. Form and 

 capsule are seen most distinctly with direct 

 agar microscopy and direct India ink agar 

 microscopy. Encapsulated. Non-motile. 

 Gram-negative. 



Gelatin: No liquefaction in one month. 



butyrous. This species is not fastidious in its 

 growth requirements, although colonies are 

 small. It grows well on tap-water agar plus 

 0.5 per cent peptone. 



No acid from glucose, sucrose, lactose, 

 maltose, adonitol, dulcitol, sorbitol, inosi- 

 tol, rhamnose and salicin. After six weeks, 

 slight acid in arabinose and xylose. 



Indole not produced. 



Non-hemolytic. 



Grows at temperatures between 5° and 

 30° C. No growth at 37° C. 



Source: Originally found in the waters of 

 a woodland lake. Later isolated from fresh- 

 water ponds and occasionally from soil. 

 Sturges (Absts. of Bact., 7, 1923, 11) briefly 

 reports the presence of organisms with the 

 same unusual morphology in ham-curing 

 brines. 



Habitat: Presumably widely distributed 

 in fresh water and in soil. 



Agar colonies: Round, smooth edges. 



Genus VII. Spirillum Ehrenberg, 1832.^ 

 (Physik. Abhandl. k. Akad. Wissensch. Berlin, 1832, 38.) 

 Spi.ril'lum. Gr. noun spira a spiral; M.L. dim.neut.n. Spirillum a small spiral, generic 

 name. 



* Prepared by Dr. J. 0rskov, Director, Statens Seruminstitut, Copenhagen, Denmark, 

 November, 1953. 



t Revised by Prof . Robert S. Breed, Cornell University, Geneva, New York, April, 1954, 

 based on a Monograph by Giesberger, Inaug. Diss., Delft, Nov. 30, 1936. 



