the maximum and minimum temperatures. It has further 

 a temperature at which it reaches its greatest develop- 

 ment, the optimum temperature. That at which bacteria 

 are destroyed is termed the death temperature. 



Some will grow at temperatures approaching the 

 freezing point of water, others at a heat of 150 degrees 

 Fahrenheit ; the greater number however find their maxi- 

 mum growth at a heat of 90 to 100 degrees Fahrenheit, 

 the heat of the animal body and of freshly drawn milk. 



The growth of most of the bacteria ceases or is very 

 slow at temperatures lower than 50 degrees Fahrenheit. 



Milk is one of the very best media for the growth of 

 a great variety of bacteria, especially if the temperature 

 is near body-heat, thus immediately after milking. 



The aim of the creameryman is to receive the milk 

 at the creameries as fresh as possible, with the lowest pos- 

 sible number of bacteria in it. He may then, by judicious 

 means, lead the fermentation processes in the direction 

 best fitted for the quality of the products he intends to 

 make. 



It is up to the dairymen to see that the milk is 

 handled on the farm in such a manner as is most favor- 

 able to the requirements of the creamerymen. 



13 



