MILLER'S SPIRILLUM, 403 



Another spirillum that has been likened to that of 

 Koch is the one obtained by Miller from a carious tooth. 

 It has so many characteristics in common with the or- 

 ganism of Finkler and Prior that Miller was inclined 

 to consider them identical. In morphology they are 

 indistinguishable. (See Fig. 81.) It grows rapidly, 

 and, like the spirillum of Finkler and Prior, causes 

 rapid liquefaction of gelatin with the coincident pro- 

 duction of a peculiar aromatic odor. 



FIG. 81. 



Spirillum of Miller. From agar-agar culture twenty-four hours old. 



The colonies on gelatin plates appear after twenty- 

 four hours as small, transparent pits of liquefaction, in 

 the centre of which can be seen a minute white point, 

 the colony itself. Under a low lens the largest of these 

 points are uniformly granular and regularly round, and, 

 as a rule, are surrounded by a peripheral zone that is a 

 little darker than the central portion of the colony. 

 The circumference is delicately fringed by short, cilia- 

 like prolongations of growth which are not, as a rule, 

 straight, but are twisted in all directions and can only 

 be detected upon very careful examination. (See a, 

 Fig. 82.) When located deep in the gelatin the col- 

 onies are round, sharply circumscribed, of a pale yel- 



