294 KAN-ICHIRO MORISHIMA 



of acid production. We attempted to accomplish this result by add- 

 ing rhamnose (0.1 to 0.25 per cent) to brilliant green lactose agar, in 

 the expectation that the daughter colonies within the typhoid colonies 

 would furnish such a positive characteristic; however, we soon per- 

 suaded ourselves that this method has no practical value. 



13. Salicin. No daughter colonies developed. 



14. Sucrose. No daughter colonies developed. 



15. Xylose. Fifty strains were planted. All xylose slow fermenters, 

 thirteen in number, gave rise to daughter colonies on plates containing 

 from 2 per cent to 0.04 per cent of xylose. The rapidly fermenting 

 strains did not give rise to daughter colonies. 



Sometimes xylose plates which contain 0.25 per cent glucose or which 

 contained brilliant green eosin (Teague and Clurman) were used without 

 interfering with the growth of the daughter colonies. 



16. Control plain plates. 



Some typhoid bacilli produced papillae-like forms on plain 

 plates two or three weeks later when the plates w^ere nearly 

 dried up; such papillae sometimes occur also on plain plates 

 inoculated with paratyphoid bacilli or Bad. coli. They never 

 increase in size or in thickness. Therefore, we could not consider 

 them true daughter colonies. 



Under anaerobic conditions, we tested four strains, xylose 

 slow fermenters (Rawling's, C-59, 57 and C-188) on 1 per cent 

 xylose china blue plates; only two strains (C-59 and 57) produced 

 daughter colonies on the eighth day; while under aerobic con- 

 ditions, all four strains produced daughter colonies within three 

 to five days. 



RELATIONSHIP BETWEEN RAPID AND SLOW XYLOSE FERMENTERS 



Kowalenko (1910, 1911) obtained Bad. coli cultures from Neisser, 

 Massini (1907) and Burk,and tried to separate fermenters and non- 

 fermenters from them after plating on Endo plates, and also from cul- 

 tures which he isolated from a fever patient's stool on the Endo plate. 

 He always obtained red-colored colonies after plating on Endo plates 

 from a red-colored colony on the Endo plate, but he obtained white colo- 

 nies and red colonies from a white colony on replating just as we 

 observed above. He reached the conclusion after more study that 

 mutation of bacteria could not be effected by influences from without, 



