242 MASS. EXPERIMENT STATION BULLETIN 187. 



the action of clarification upon pure cultures, and the results secured by- 

 direct counts, — all of which testify to the elimination of micro-organisms 

 by the clarifier in no small degree. No differentiation between pathogens 

 and non-pathogens can be made. The larger the micro-organisms, speak- 

 ing generally, the greater the proportion cast out. 



10. Frequently, yes, commonly, the action of the clarifier upon the micro- 

 organisms is so significant as to alter their respective power or capacity 

 for change in the milk. This is easily detectable by the appearance of 

 clarified and unclarified samples when observed from day to day over a 

 period of time. It is also readily determined by filtering out the curd, 

 when formed, upon filter paper, and allowing it to undergo fermentation 

 for a few days under proper conditions. 



In Part II we shall consider this alteration in clarified milk as com- 

 pared with unclarified milk. The work has progressed to a point that 

 it is safe and only fair to say that an intimate study is confirming the 

 general statements above. 



