QUANTITATIVE BACTERIAL ANALYSIS 



26t 



Counts on " certified " or " inspected " milk shall be expressed 

 ss closely as the dilution factor will allow. 



The whole number of colonies on the plate shall be counted 

 the practice of counting a fractional part being resorted to only^ in 

 case of necessity, such as partial spreading. 



Fig. 66. 



Counting-Box, 



Various counting devices have been recommended by differ- 

 ent workers. The more simple ones, where the whole plate cart 

 be seen at once, are more desirable on account of there being less 

 likelihood of recounting colonies. Colonies too small to be seen 

 with the naked eye or with slight magnification shall not be 

 considered in the count. 



