SPORULATION 13 



Endospores are produced under stress of circumstances, when 

 certain agencies' or conditions, such as absence of food, drying, and 

 heat, threaten the extinguishment of the organism. Spores are 

 bright, shining, oval, or round bodies, which do not take aniline 

 dyes readily, and which, when they are stained, retain the color 

 more tenaciously than the adult cells. They resist heat, often with- 

 standing a temperature of 150 C. dry heat for an hour. Steam 

 under pressure at a temperature of 150 C. will invariably kill them 

 after a short exposure. 



Spores are situated either in the ends of the adult organism 

 (polar) or in the middle (equatorial), and the spore is discharged 

 (sporulation) either from the end or through the side. 



o C O O 



FIG. 12. Spore germination, a, direct conversion of a spore into a bacillus 

 without the shedding of a spore- wall (B. leptosporus); b, polar germination of 

 Bad. anthracis; c, epuatorial germination of B. subtilis; d, same of B. mega- 

 terium; e, same with "horse-shoe" presentation. (After Novy.) 



The spore is developed in the bacterial cell as follows: If the 

 organism is a mobile one it becomes quiet before sporulation, during 

 which the flagella are retained. The diameter becomes greater in 

 one portion of the cell, and dust-like particles appear, then a bright 

 spot; a capsule then forms, the spore escapes, and the parent cell 

 dies. { 



>t Certain spore bearing bacteria grown for a week at 42 C. lose the 

 power to form spores, likewise their progeny. As a rule the anthrax 

 bacillus does not form spores in the bodies of animals. Free oxygen 

 'is required for sporulation by some bacteria. Qne_spore qm^us pro- 

 duced by an adult cell. Some forms of bacteria can be differentiated 



