ARAO ITANO AND JAMES NEILL 



425 



An interesting phenomenon was observed in the broth at pH 5, 

 6, and 9. At the time given in Table III only a few spores had germi- 

 nated. These first vegetative cells did not exhibit the characteristic 

 motility of this species, neither did rapid multiplication begin at once. 

 Several hours later, however, after most of the spores had germinated 

 the vegetative cells became actively motile and multiplication became 

 much more rapid, indicating that by the hfe processes of the organisms 



TABLE IV. 



Time in Hours Required by B. suUilis to Reach Variotis Stages of Development at 



Different pH Values. (Temperature 37°C.) 



Figures represent average of four experiments. 



S indicates no apparent change except slight swelling and a certain loss of 

 refrangibility. 



the reaction of the medium was approaching the optimum. In view 

 of facts shown in a previous publication,^ this behavior may be ex- 

 plained as a manifestation of the beginning of the automatic adjust- 

 ment of the medium. 



The behavior in pH 10 was also interesting. Only a few of the 

 spores germinated and these passed into the spore stage in a compara- 

 tively short time without much further multiplication. 



^ Itano, A., Massachusetts Agric. Exp. Sta., Bull. 167, 1916, 174. 



