igoo-i.] The Ripening of Cheese. 123 



Following de Freudenreich's plan of obtaining the liquefying germs, 

 surface cultures were occasionally made. This method also helped in 

 the isolation of yeasts, the surface colonies of which were far easier to 

 spot than those deep in the gelatin. 



Anaerobic methods of culture failed to show any obligate anaerobes. 



Pake's apparatus was used for counting the colonies, but when these 

 were too numerous, a low power of the microscope was employed and 

 from five to ten per cent, of the total number of microscope fields in a 

 Petri dish of eighty m.m. diameter were counted, and computations 

 made therefrom. 



