166 MASS. EXPERIMENT STATION BULLETIN 167. 



2X indicates the medium of double concentration. 

 F.N. indicates the formol titrating nitrogen. 



In this preparation n/1 HCl and n/1 NaOH were used instead of n/5 

 because it appears that the smaller the quantity the easier the manipu- 

 lation and the greater the accuracy. The results thus obtained are fairly 

 satisfactory. 



In flasks 4 and 5 the contents became turbid with the addition of the 

 n/1 acid, while all others remained clear. This turbidity may be due to 

 the precipitation of meta-protein or some other similar substance. 



Acclimatization of the Culture. 



In general bacteriology it is commonly recognized that environment 

 exerts a great influence upon the physiologic function and morphology 

 of microorganisms. To secure an organism of constant habits the author 

 resorted to the following procedure : — 



Six flasks containing 25 cubic centimeters of Medium IV. (Ph = 6.80) 

 were prepared. One of these was inoculated with B. subtilis which was 

 obtained from the American Museum of Natural History, New York. 

 After maintaining this flask at 37° C. for twenty-four hours, subinocula- 

 tion from it was made into another flask of the same lot as above, by 



