I 6 . BACTERIA 



found in bacteria of high thermal death-point, are called by 

 Heuppe arthrospores. It is believed that they are without 

 significance. Arthrospores are common among the micrococci 

 and may be associated with capsule formation and cell enlarge- 

 ment. The whole cell may stain more intensely. They are also 

 to be sought among the Streptothrix genus. 



Spores resist chemicals for a long period, and withstand drying, 

 even in lime plaster, for years. It is believed that the thick 

 capsule enables them to resist these deleterious agents. 



FIG. 13. Pest bacilli showing capsules. (Kolle and Wassermann.) 



Sporulation is more apt to occur under poor nutritive conditions. 



The anthrax bacillus thrives at i3C. but cannot sporulate 

 below i8C. Anthrax spores have been known to resist the 

 germicidal action of a 5 percent carbolic acid solution for forty 

 days. 



Capsules. Certain well-known pathogenic bacteria have 

 thick well-marked capsules. The pneumococcus, pneumobacillus, 

 and Bacillus aerogenes capsulatus, are well-known examples of 

 such capsulated organisms. The capsule is not always constant. 

 It often disappears when the organism is grown in culture 

 media (Figs. 12 and 13). 



