FAMILY PSEUDOMOiVADACEAE 



213 



bb. Light yellowish-orange growth on potato. 



2. Spirillum serpens. 



aa. No liquefaction of gelatin. Of small size (0.5 micron in diameter). 

 b. Colonies on agar white becoming brownish black and slightly 

 wrinkled. 



3. Spirillum itersonii. 

 bb. Colonies on agar white and smooth. 



4. Spirillum tenue. 

 2. No volutin granules observed. 



b. Single flagellum. 



5. Spirillum virginianum. 

 bb. Tuft of flagella. 



6. Spirillum minus. 

 II. Over one micron in diameter. 



1. Grows poorly on peptone agar and potato. 



7. Spirillum kutscheri. 



2. Xot positively known to have been cultivated on artificial media. Very 

 evident volutin granules. 



S. Spirillum volulans. 



3. Cells more or less deformed by fat drops. 



9. Spirillum lipoferum. 



1. Spirillum undula rMiiller) Ehren- 

 berg. {Vibrio undula MtiUer, Animal- 

 cula infusoria et marina, 1786 ; Ehrenberg, 

 Infusionstierchen, 1838; Spirillum 

 undula minor Kutscher, Cent. f. Bakt., 

 I Abt., 18, 1895, 614.) From Latin, 

 undulatus, wave-like. 



Stout threads, 0.9 micron in diameter, 

 with one-half to three turns. The wave 

 lengths are 6 microns. Width of spiral, 

 3.0 microns. Tufts of three to nine 

 flagella at each pole. Volutin granules 

 present. Gram-negative. 



Gelatin colonies : The surface colonies 

 are circular, granular, greenish-yellow, 

 entire. 



Gelatin stab: Thick, white, rugose 

 surface growth. Very slow liquefaction. 



Agar colonies: Grayish-white, smooth. 



Broth : Turbid. 



Potato: Grayish-brown growth. 



Indole not formed. 



Catalase positive. 



Nitrites not produced from nitrates. 



Aerobic, facultative. 



Optimum temperature 25 °C. 



Cohn (Beitrage z. Biol. d. Pflanzen, /, 

 Heft 2. 1875, 132) reports that he could 



not distinguish this organism from Vibrio 

 prolifer Ehrenberg. 

 Habitat: Putrid and stagnant water. 



2. Spirillum serpens (MuUer) Winter. 

 {Vibrio serpens Miiller, Animalcula in- 

 fusoria et marina, 1786, 43; Winter, in 

 Rabenhorst's Kryptogamen-Flora, 1, Die 

 Pilze, 1884, 63.) From Latin, serpens, 

 serpent. 



Long, curved rods with two to three 

 wave-like undulations, 0.8 to 1.0 micron 

 in diameter; wave length, 8 to 9 microns. 

 Width of spiral 1.5 to 1.8 microns. Vo- 

 lutin granules in cytoplasm. Motile, 

 possessing tufts of flagella at both poles. 

 Gram-negative. 



Gelatin colonies : Yellowish to brown- 

 ish, granular, entire. 



Gelatin stab : Yellowish surface growth. 

 Slow liquefaction. 



Agar colonies : Heavj- cream-colored 

 growth. 



Agar slant: Grayish, with yellowish 

 center, granular, entire. 



Broth: Turbid. 



Litmus milk : Unchanged. 



Potato: Clear orange-yellow growth 



Indole not formed. 



