BACTERIA PATHOGENIC FOR ANIMALS. 137 



CHAPTER IV. 



BACTERIA PATHOGENIC FOR ANIMALS BUT NOT FOR MAN. 



Bacillus of Symptomatic Anthrax. (Bellinger and Feser.) 



(Cliarbon symptomatique. Arloing, Cornevin, and Thomas. ) 



Origtn. This bacillus, described already in 1879, has only 

 lately been isolated, and by animal inoculation shown to be the 

 cause of the " black-leg" or ''quarter-evil" disease of cattle. 



Form. Large slender rods, which swell up at one end or in 

 the middle for the spore. 



Properties. They are motile, and liquefy gelatine quite 

 rapidly. 



A rancid odor is developed in the cultures. 



Cultures. The growth occurs slowly, and only in an atmo- 

 sphere of hydrogen, being very easily destroyed by oxygen and 

 carbon dioxide ; grows best at blood heat ; under 15 C. no 

 growth. 



Glucose-gelatine. In a few days little round colonies develop, 

 which, under low power, show hairy processes around a compact 

 centre. 



Stab Cultures in full test tubes. The growth first in the lower 

 portion of the tube not very characteristic. Gases develop 

 after a few days, and the gelatine becomes liquid. 



Agar at brood temperature, in 24 to 48 hours, an abundant 

 growth with a sour odor and abundant gas formation. 



Staining. Ordinary methods. Gram's method is not appli- 

 cable to the rods ; but the spores can be colored by the regular 

 double stain for spores. 



Pathogenesis. If a small amount of the culture be injected 

 under the skin of a guinea-pig, in twenty hours a rise of tempera- 

 ture, pain at the site of injection, and in a few hours more 

 death. At the autopsy, the tissues blackened in color and 

 soaked with a bloody serous fluid ; in the connective tissue large 

 collections of gas, but only in the neighborhood of the point 



