PASTEURIZING AND STERILIZING MILK 121 



one of the tubes of milk treated by each process with the 

 plate cultures, and leave the other tubes with a tube of the 

 fresh milk at the room temperature. 



At the next exercise note carefully the condition of the milk 

 in each of the various tubes and also the number of colonies 

 on the agar plates. 



Examine the cultures made in Exercise LIII. 



