i8 The Story of the Bacteria 



the middle, and in the place of one there are 

 two full-fledged bacteria. These may at once 

 fall apart and each new individual go on di- 

 viding as before, or they may cling together, 

 forming threads or chains of varying length, 

 or clumps or masses. 



So rapid is this mode of reproduction that 

 a single germ by this process of growth and 

 subdivision- may give rise to more than sixteen 

 and a half millions of similar organisms within 

 twenty-four hours. It has been calculated by 

 an eminent biologist that, if the proper condi- 

 tions could be maintained, a little rod-like 

 bacterium, which would measure only about a 

 thousandth of an inch in length, multiplying 

 in this way, would in less than five days make 

 a mass which would completely fill as much 

 space as is occupied by all the oceans on the 

 earth's surface, supposing them to have an 

 average depth of one mile. 



Let not the timid soul tremble, however, for 

 the principle of the survival of the fittest and 

 the influences of environment have kept our 

 prolific organisms so well in check that the 

 world had grown very old and its favored 



