280 TEXT-BOOK OF BACTERIOLOGY. 



are usually shorter and thicker, but nevertheless more strongly- 

 bent, than those of the vibrio of cholera asiatica. Like the latter, 

 in liquid media it forms longer threads — twisted spirilla of varying- 

 extent, the coils being generally rather steep. The vibrio Metsch- 

 nikoff has lively voluntary movement, which is produced by a long, 

 fine, undulating flagellum at the end of each cell, which can be 

 stained by Loffler's method. 



The occurrence of spores is no more proved with the vibrio 

 Metschnikoff than with the cholera bacterium, and the positive re- 

 sults of Gamaleia (who claims to have established in the interior 

 of the single links the presence of structures accessible to double 

 staining) have never been confirmed. Facts are wanting to show 

 that this micro-organism is possessed of great resisting power. It 

 stands in this respect on an equal footing with the cholera vibrio, 

 and, like it, succumbs to the influence of acids, of high tempera- 

 tures, and especially of drying, just as rapidly and completely. 

 Its attitude toward oxj'gen and growth at ordinary as well as at 

 breeding temperature is similar to that of Koch's comma bacillus. 



Gamaleia's vibrios are easily stained. It is frequently seen that 

 in treating with watery color- solutions only the two ends of the 

 single links are colored, while the centre remains pale and sep- 

 arated from its surroundings as a bright gap, an appearance met 

 with in the bacteria of hen cholera in a more pronounced manner. 

 The vibriones are decolored by Gram's method. 



On the gelatin plate the colonies appear after the average 

 time requisite. 



Their appearance is intermediate between those of Koch's and 

 Finkler's vibrio and may be ranged with Deneke's bacterium. It 

 must be remarked, however, that the colonies do not always de- 

 velop in the same manner. 



Take two gelatin plates of Koch's comma bacillus and Metsch- 

 nikofC's vibrio three days old. They present an altogether different 

 picture. In one of them we see the gelatin closely beset with small 

 depressions, sharply bordered and whitish, similar to air -bubbles; in 

 the other we are struck by capacious saucer-like, circular areas of 

 liquefaction filled with grayish-white, turbid contents, and so strongly 

 reminding one of the appearance of the colonies of Finkler's vibrio 

 that at the first glance we may think that it is in fact the latter. 

 In looking more closely we may recognize, even with the naked 

 eye, between and along the large, strongly-liquefied colonies, a 

 number of smaller ones lying partly at some depth in the gelatin 

 and partly near the surface. They have, however, only caused a 

 moderate softening of the gelatin ; they appear as round cavities 



