58 o. iSHii 



medium is not suitable for the agglutination test for Bad. 

 paratyphosum A. 



Occasionally spontaneous agglutination in pepton water 

 cultures is difficult to prevent, while in plain broth it is relatively 

 easy to prevent; in pepton water there is but a slight tendency 

 to spontaneous agglutination even with non-spontaneous agglu- 

 tinating bacilli. Specific agglutinations with pepton water 

 cultures were slightly weaker than with plain or glucose broth 

 cultures. With formalin the reaction was slightly stronger than 

 without. 



With agar cultures the agglutination reaction was generally 

 slow and weak and appeared somewhat incomplete, dependmg 

 however upon the strain and age of the culture. With or without 

 formalin almost the same results are obtained with non-spon- 

 taneous agglutinating bacilli. 



Bact. paratyphosum B. Glucose broth cultures of Bad. para- 

 typhosum B usually show weak motihty and strong spontaneous 

 agglutination, which is not prevented when treated with formalin ; 

 even non-spontaneous agglutinating bacilli give the same result. 

 This medium does not appear to be satisfactoiy for the Widal 

 test with Bad. paratyphosum B. 



Cultures in plain broth and pepton water showed more vigor- 

 ous motility and ahnost the same agglutinating reaction with 

 specific serum. But in pepton water with non-spontaneous 

 agglutinating baciUi, there was a slight tendency to spontaneous 

 agglutination even when the cultures were mixed with salt solu- 

 tion or with formalin. It appears that plain broth cultures are 

 more reliable than are those in pepton water. 



The agar cultures showed weak specific agglutination m com- 

 parison with the other three kinds of media, but did not have the 

 tendency to spontaneous agglutination. 



Bact. call. Glucose broth cultures of most strains of Bad. 

 coli grown for eighteen to twenty-four hours at 37°C. showed con- 

 siderable spontaneous agglutination with both spontaneous and 

 non-spontaneous agglutmating bacilli; hence this medium can- 

 not be used for the specific agglutination test. 



