234 



MASS. EXPERIMENT STATION BULLETIN 187. 



Table XL VIII. — Effect of Clarification on Pure Cultures of Molds and 

 Yeasts. 



Rhizopus nigricans spores. 



Penicillium glaucum spor( 



10, or 1,000 per cubic centimeter, 

 40, or 4,000 per cubic centimeter, 

 20, or 2,000 per cubic centimeter. 



Sterile, 



1, or 100 per cubic centimeter, 



2, or 200 per cubic centimeter. 



Sterile. 

 Sterile. 

 SterUe. 



Oidium lactis spores. 



Saccharomyces cerevisice. 



Aspergillus nige.r spores. 



16, or 16,000 per cubic centimeter, 

 7, or 7,000 per cubic centimeter, 

 5, or 5,000 per cubic centimeter. 



6, or 600 per cubic centimeter, 

 4, or 400 per cubic centimeter, 

 1, or 100 per cubic centimeter. 



Sterile. 

 SterUe. 

 SterUe. 



Note. — Molds were grown in pure culture; spores were swept up with sterile filter paper and 

 introduced into 1,000 cubic centimeters of sterile milk. After thorough agitation milk was clari- 

 fied under sterile conditions. Counts were made immediately before and after. 



Cultures of Saccharomyces cerevisice were grown on wort medium at room temperature for three 

 days; 5 cubic centimeters of the culture were inoculated directly into 1,000 cubic centimeters of 

 sterile milk. After thorough agitation, milk was clarified under sterile conditions. Counts were 

 made immediately before and after. 



' "Sterile" means that no colonies appeared when plates were made of the dilutions indicated. 

 ' Oidium was grown directly in sterile milk at room temperature for three days, untU small 

 colonies appeared on surface. 



