564 SA CTERIOL OGY. 



thrax bacilli in culture and the bacilli of malignant 

 oedema in the bodies of animals are frequently seen to 

 do. Under the hanging drop the bacilli are observed 

 to be actively motile, and in stained preparations flagella 

 may be demonstrated surrounding the periphery. The 

 spores are elliptical in shape, usually thicker than the 

 bacilli, lying near the middle of the rods, but rather 

 toward one extremity. This gives to the bacilli con- 

 taining spores a somewhat spindle shape. 



Stains with the ordinary aniline dyes, but not with 

 Gram's method, or only with difficulty and after long 

 treatment or intense colors. 



Biological Characters. Like the bacillus of malignant 

 oedema this is also a strict anaerobe, and cannot be cul- 

 tivated in an atmosphere in which oxygen is present. 

 It grows best under hydrogen, and does not grow under 

 carbonic acid. This bacillus develops at the room-tem- 

 perature in the usual culture media, in the absence of 

 oxygen, but it grows best in those to which 1.5 to 2 per 

 cent, of glucose or 5 per cent, of glycerin has been added. 



Growth on Agar. The colonies on agar are some- 

 what more compact than those of malignant oedema, but 

 they also send out projections very often. In agar stick 

 cultures, in the incubator, growth occurs after a day or 

 two also some distance below the surface, and is accom- 

 panied by the production of gas and a peculiar disagree- 

 able acid odor. 



Pathogenesis. The bacillus of symptomatic anthrax 

 is pathogenic for cattle (which are immune against ma- 

 lignant oedema), sheep, goats, guinea-pigs, and mice; 

 horses, asses, and white rats when inoculated with a cul- 

 ture of this bacillus present only a limited reaction; and 

 rabbits, swine, dogs, cats, chickens, ducks, and pigeons 



