THE MORPHOLOGY OF BACTERIA II 



5. THE FORMATION OF ENDOSPORES 



Under unfavorable conditions of environment, as deficiency of 

 food supply, unfavorable temperature or drying, bacterial cells 

 may produce within their substance strongly refracting, roundish, 

 or oval bodies known as endospores. The formation of endo- 

 spores in Bact. anthracis consists in a contraction of the cellular 

 protoplasm which collects as a naked body toward one pole of the 

 rod, Fig. 6, H. This naked mass continues to contract through loss 

 , of water of imbibition, and becomes more strongly refracting and 



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FIG. 6. Showing methods of spore germination. 



Polar germination of B. butyricus after Prazmowski. B. Equatorial germination of 

 B. subtilis after Prazmowski. C-D. Equatorial germination of B. tumescens (c) and 

 of Bact. carotorum after A. Koch. E-F. Polar germination of Bact. sessile after L. 

 Klein. H. Germination by absorption of B. anthracis after De Bary. G. Endo- 

 germination in Spirillum endoparagogicum after Sorokin. I-K. Spore formation in 

 Bact. anthracis after Migula. 



symmetrically oval in form. Here it becomes invested with a 

 capsule, where it remains enclosed in the empty cell until by 

 the dissolution of the latter it is set free. In B. subtilis the 

 cell plasma becomes granulated, and later a number of minute 

 strongly refracting granules appear, which collect and aggregate 

 themselves at one pole. These by their coalescence produce a 

 dense mass which by later investing itself with a membrane 

 becomes a mature spore. A spore consists of a central highly 



