BACILLUS MUCOSUS CAPSULATUS 721 



The bacillus is characteristically surrounded by a well-developed 

 capsule which is most perfectly demonstrated in preparations taken 

 directly from some animal fluid, such as the secretion or exudate 

 from infected areas. It is also seen, however, in smears made from 

 agar or gelatin cultures. The capsule is usually large, twice or three 

 times the size of the bacillus itself. When seen in chains or in 

 groups, several bacilli may appear to be inclosed in one capsule. 

 Prolonged cultivation on agar or gelatin may result in disappearance 

 of the capsule, The bacillus is easily stained with the ordinary 



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FIG. 71. BACILLUS MUCOSUS CAPSULATUS. 



dyes, but is decolorized when stained by the Gram-method. Capsules 

 may often be seen when the more intense anilin dyes are employed. 

 They are brought out with much regularity by any of the usual 

 capsule stains. 



Cultivation. B. mucosus capsulatus is easily cultivated. It grows 

 readily on all the usual culture media, both on those having a meat- 

 infusion basis and on those made with meat extract. Growth takes 

 place at room temperature (18 to 20) and more rapidly at 37.5 C. 

 A temperature of 60 C. and over kills the bacilli in a short time. 

 The thermal death-point- according to Sternberg is 56 C. Growth 



