ILLINOIS DAIRYMEN'S ASSOCIATION. 123 



tors; to the introduction of germ life in varying qualities, and to the 

 presence of conditions which favor a rapid growth and development of 

 the organisms originally seeded in the milk. 



The composition of milk is such that bacteria find in it the most 

 favorable conditions for growth, all the necessary food nutrients are there 

 to promote rapid changes, and if the temperature is favorable a single 

 organism will multiply and increase its numbers many fold in a short 

 period of time. 



SLIDE- NO. 2.— TEMPERATURE AND BACTERIAL GROWTH. 





PROGENY OF A 

 SINGLE GERM 

 in twelve: hours 



NO. 2. — Showing the effect of cooling milk on the growth of bacteria. The 

 beneficial results of early chilling are readily apparent. 



The factors which account for this infection may be briefly summed 

 up in cleanliness and temperature. Unless the temperature of milk is 

 kept at a point where bacterial multiplication cannot go on even a few 

 germs in the course of hours will be able to increase so that the aggregate 

 will be very large. But our purpose is to point out more specifically the 

 way in which bacleria gain entrance to milk. 



We may divide the infection of milk into several factors: 



Utensils. 



Fore milk. 



Dirt derived from air and cow. 



