76 



O. ISHII 



TABLE 2— Continued 



Key, — No change. 



(a) Different organisms showed a differentiation into two 

 types of colony at different periods of growth, Bact. coli showing 

 a change in from 2 to 30 days. 



(6) Bact. paratyphosum A showed the change within 3 to 14 

 days (some strains however, remaining constant even after 

 30 days). 



(c) Bact. paratyphosum B showed a transition period of from 

 4 to 30 days, while some strains did not show the spontaneously 

 agglutinated type of colony even after 60 days. 



(d) Bact. dysenteriae group showed changes in from 4 to 22 

 days (some strains bemg negative after 30 days). 



(e) Bact. enteritidis changed in from 5 to 24 days. 



(0 Bact. typhosum showed the longest period, the time vary- 

 ing from 6 to 50 days in some strains, whUe others did not show 

 changes even after 3 months or more. 



From colonies of known type (as determined above) isolated 

 on agar plates, the different members of the colon-tj^phoid group 

 were inoculated into broth media and allowed to grow at room 

 temperature without sub-culture, plates being made every 

 five or ten days to determine the type of colony. In 33 strains 

 of Bact. typhosum of both types, changes were observed to take 

 place in 30 strains in fifteen to ninety days, while three strains, 



