14 BACTERIA 



from each other only by the way in which they sporulate, whether 

 from the poles or the equator. /^ 



j^The Bacteriacea are the prominent spore producers. Certain 

 round bodies found in bacteria of low thermal death-point, are 

 called by Heuppe arthrospores. It is believed that they are without 

 significance. A high thermal death-point in bacteria indicates 

 that the organism produces spores. Arthrospores are common 





FIG. 13. Capsules. Bact. pneumonia (Friedlander) . (After Weichselbaum 

 from Frost and McCampbell.) 



among the micrococci and may be associated with capsule forma- 

 tion and cell enlargement. The whole cell may stain more 

 intensely. They are also to be sought among the Strep to thrix 

 genus. t 



^ 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. 4> 

 ^ Sporulation is more apt to occur under poor nutritive conditions, 

 The anthrax bacillus thrives at 13 C. but cannot sporulate below 



