62 PHARMACEUTICAL BACTERIOLOGY 



Microbes do not multiply in the air itself, rather upon the organic dust 

 particles present, provided warmth and moisture are adequate. 



Since microbes multiply rapidly, perhaps one septation in from twenty 

 to thirty minutes, it is evident that the rate of numerical increase, under 

 favorable conditions, is very great. Allowing thirty minutes for each 

 septation, there would be a colony of 2,097,152 microbes in ten hours, 

 developed from a single cell, or about 75,000,000,000,000 cells in twenty- 

 four hours. However, under natural conditions septation never proceeds 

 in such uniform ratio. All manner of checks to septation come into play 

 sooner or later which may finally bring about complete cessation of septa- 

 tion and sporulation. 



