482 BACTERIOLOGY. 



to believe that it was related etiologically to the gastro- 

 enteritis from which the chickens had been suffering. 



Morphologically it appears as short, curved rods and as 

 longer, spiral-like filaments. It is usually thicker than 

 Koch's microspira and is at times much longer, while 

 again it is seen to be shorter. It is usually more dis- 

 tinctly curved than the " comma bacillus." (Fig. 79.) 



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- 



FIG. 80. 



Colony of microspira Metchnikovi in gelatin, after thirty hours at 20 to 

 22 C. X about 75 diameters. 



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-size 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 deli- 

 cate radii. (Fig. 80.) 



In gelatin stab-cultures the growth has much the 



