318 BACTERIOLOGY. 



It is a short rod, with rounded or slightly pointed 

 ends, that usually takes up the stain somewhat irreg- 

 ularly. (See Fig. 64.) When examined in stained 

 preparations its continuity is marked by alternating 

 darkly and lightly stained areas. It is usually seen as 

 a single rod, but may occur in pairs, and less frequently 

 in longer filaments. 



The question as to its spore-forming property is still 

 an open one, though the weight of evidence is in oppo- 

 sition to the opinion that it possesses this peculiarity. 

 Certain observers claim to have demonstrated spores in 

 the bacilli by particular methods of staining, but this 

 statement can have but little weight when compared 

 with the behavior of the organism when subjected to 

 more conclusive tests. For example, it does not, at 

 any stage of development, resist exposure to 3 per cent, 

 carbolic acid solution for longer than five minutes, nor 

 to 1 : 5000 sublimate solution for more than two min- 

 utes. It is destroyed in ten minutes in some experi- 

 ments, and in five in others, by a temperature of 55° C, 

 and when dried it loses its vitality, according to dif- 

 ferent observers, in from thirty to forty days; all of 

 which speak directly against this being a spore-bearing 

 bacillus. 



It is not motile, and does not, therefore, possess 

 flagella. 



It grows readily on the ordinary nutrient media at 

 from 25° to 38° C. 



Upon nutrient agar-agar, both with and without gly- 

 cerin, it appears as a moist, opaque, glazed layer, with 

 nothing characteristic about it. This is true both for 

 smear-cultures and for single colonies. 



Its growth on gelatin is much less voluminous than 



