TEMPERATURE AND B. COLI 



139 



the B. coli content of milk must be regarded as due more to 

 reproduction than to original contamination. Diagram No. 

 Ill, which shows the B. coli content of the Ottawa raw milk 

 supply compared with the mean atmospheric temperature, 

 demonstrates very clearly the effect of temperature. In the 

 autumn months the curves do not correspond because the mode 

 of the B. coli curve is lowered during the hot simuner months 



Diagram No. Ill 



50 s 



3 



by artificial cooling of the milk and the temperature of the milk 

 is, consequently, not proportional to the atmospheric, but it is 

 evident that artificial cooling is abandoned before the natural 

 agencies become entirely operative. It is also interesting to 

 note that after the very cold winter weather the B. coU content 

 does not increase imtU the mean atmospheric temperature 

 exceeds the critical temperature. 



