SPIRILLUM TYROGENUM. 477 



to defend, without any new and better reason, those original 

 expressions which they hare introduced into the science of 

 bacteriology. 



Spirillu m tyrogcnum. 

 (Cheese spirilla.) 



These organisms were isolated by Deneke in the 

 iiuthor's laboratory from cheese which had been kept for 

 a long time ; morphologically and on cultivation they 

 show a greater resemblance to Koch's comma bacilli than 

 do Finkler's spirilla, but like the latter they can be 

 definitely distinguished from the cholera bacilli by 

 certain culture characteristics. 



The individual bacilli are somewhat smaller than Morphologic* 

 Koch's bacilli, and often show very long spirillar threads el 

 with somewhat narrower twists and smaller screws. In 

 drop cultivations they show active movements. 



On gelatine plates the youngest colonies form small Cultivation*, 

 white points after 24 hours, and under a low power they 

 present the form of circular discs with sharp outlines, 



. </ ""-- Fig. 128. Colonies of cheese 

 1 ^X> spirilla X 80. 



^r- a, after 16 hours. 



Fig. 127. Cheese spirilla &, 24 



X 700. c, 36 



and of a dark, greenish-brown colour. At a later period 

 the margin appears somewhat lighter, the centre of a 

 dark yellow colour ; at the same time liquefaction of the 

 gelatine commences, and the sharp outline of the colony 

 not uncommonly disappears. The liquefaction of the 

 gelatine is more energetic than in the case of the cholera 

 bacilli, but does not occur so quickly as in Tinkler's. 

 This fact is seen also in puncture cultivations, where a 

 sac-like liquefied tube is formed within 24 hours, and at 

 a later period there is complete liquefaction of the 



