22 



L. A. JULIANELLE 



a cone-shaped liquefaction. After that the liquefaction proceeds 

 uniformly in all the cultures by stratification. The difference, however, 

 is so superficial that we would hardly suggest a classification on this 

 characteristic. 



One significant feature brought out by the tables is the ability of 

 six cultures to attack gelatin-cultures which did not a year previously 

 manifest this ability. This shows above all the variability of the organ- 

 isms to be classified a variability which emphasizes the fact that in 

 order to classify staphylococci we must depend on more substantial 

 characters than functional differences. 



TABLE 12 

 RESULTS OF AGGLUTINATION 



* Figures represent the dilution at which agglutination was observed by naked eye read- 

 ing. All controls were negative. 



Reduction of Methylene Blue, At the December, 1921, meeting of 

 the Am. Assn. of Bacteriol., Avery reported his investigation of the 

 use of methylene blue in differentiating hemolytic streptococci from 

 human and dairy sources. He found that dairy strains bovine and 

 cheese reduced methylene blue, but that the human strains did not. 

 Because of these results, we tried reducing methylene blue by our 

 staphylococcus strains. The technic of the test consisted in adding to a 

 24-hour broth culture varying dilutions of methylene blue, and covering 

 with sterile paraffin. The cultures were reincubated for a second day, 



