VIBRIO METCHNIKOVI 353 



while again it is seen to be shorter. It is usually 

 more distinctly curved than the "comma bacillus." 

 (Fig.73.) 



It is supplied with a single flagellum at one of its 

 extremities and is, therefore, motile. 



It does not form spores. 



It is aerobic. 



Its growth upon gelatin plates is usually character- 

 ized, according to Pfeiffer, by the appearance of two 

 kinds of liquefying colonies, one strikingly like those 

 of the Finkler-Prior organism, the other very similar 

 to those produced by Koch's comma bacillus, though in 

 both cases the liquefaction resulting from the growth 

 of this organism is more energetic than that common to 

 the spirillum of Asiatic cholera. After from twenty- 

 four to thirty hours the medium-sized colonies, when 

 examined under a low power of the microscope, show a 

 yellowish-brown, ragged central -mass surrounded by a 

 zone of liquefaction that is marked by a border of 

 delicate radii. (Fig. 74.) 



Fig. 74. 



Colony of viJbrlo Metohnikovi In gelatin after thirty hours at 20° to 22° C. 

 X about 75 diameters. 



In gelatin stab cultures the growth has much the same 

 general appearance as that of the cholera spirillum, but 

 is very much exaggerated in degree. The liquefaction is 

 far more rapid and the characteristic appearance of the 

 growth is lost in from three to four days. (See a, b, 

 G, d, Fig. 75.) Development and liquefaction along 



