SPIRILLUM FINKLER AND PRIOR, 473 



we find " S " forms similar to those of the cholera bacillus, 

 and also longer screw-like threads, which, however, do 

 not occur so frequently in gelatine cultivations, and do 

 not show so many twists as in similar cultivations of the 

 cholera bacilli. When examined in drop cultivations 

 they show active movement. 



According to Buclmer, Finkler's bacilli have a great Involution 

 tendency to alter their form when the state of the 

 nutrient medium is unfavourable (Buchner has there- 

 fore proposed to give the bacillus the name Vibrio 

 proteus). Under these circumstances they form some- 

 times spheres, sometimes spindles, and sometimes 

 monad-like bodies ; the latter may present an oval 

 form as much as 4 p.. in breadth, or may appear as 

 large spheres, or as very broad and fat portions of 

 twisted threads, and they are obtained very easily by the 

 addition of 5 per cent, of sugar, or 2 per cent, of 

 glycerine, to the gelatine. These structures can only 

 be looked on as pathological or involution forms. 



On gelatine plates Finkler's bacilli form after 24 Cultivation* 

 hours white points, which under a low power present 

 the appearance of circular yellow or yellowish-brown 

 discs ; in contrast to the young colonies of Koch's 

 comma bacilli the outline of Finkler's colonies is very 

 sharp, dark, and almost absolutely circular, while in the 

 case of the cholera bacilli a wavy irregular outline is 

 observed ; the colour is also distinctly darker, and the 

 surface does not present such 

 a highly refracting, granular 

 appearance as in the case of 



the true cholera colonies. a o 



Liquefaction of the gelatine Fig. 125. Colonies of Finkler 



, . , and Prior's spirilla X 80. 



begins very early : as soon ., 



. J J . , after 16 hours. 



as this occurs the outline of *, 24 ,, 



the colonies loses its sharp- 

 ness, the periphery often appears dentate or as if 

 eaten away, while, on the other hand, the external 

 zone of liquefaction has a sharp border. One can 

 often observe at this stage zones of different colour 

 in the colony ; a darker central zone, then a lighter, 



