THE MULTIPLICATION OF MICRO-ORGANISMS 227 



most interesting feature of all in this figure is the beha- 

 viour of the bacteria in Ourcq canal-water. This water, 

 containing to start with about 8,000 organisms in 1 c.c, 

 requires as long as twenty days before the numbers 



Number of 

 Bacteria in 

 1 c.c. 



90,000 



80,000 



70,000 



GO.OOO 



50,000 



40,000 -4 



30,000 



20,000 



10,000 



60 



Days. 



Fig. 17. Multiplication of Bacteria in Impure Waters. 

 (Miquel.) 



present reach 60,000, after which point a slight decrease 

 is noticed ; but the number of bacteria subsequently 

 remains almost stationary at this high level, and exami- 

 nations made of this sample at the end of six months, a 

 year, and even after, revealed practically no alteration. 

 Miquel goes on to say that the bacteria in the Seine 



a 2 



