218 BACTERIOLOGICAL EXAMINATION OF WATER. 



B. typhosus. To decide this question he immunised guinea-pigs 

 with the cultures ; of the sera so prepared, some agglutinated 

 the B. typhosus, while others agglutinated the B. coli, used 

 originally to infect the flasks ; consequently these atypical 

 bacilli appeared to be true descendants of the original cultures. 

 As a result of these experiments Remy arrived at the following 

 general conclusions : 



(1) The idea of the effacement of the B. typhosus by the 

 B. coli is not confirmed by researches on the antagonism of 

 these two organisms. 



(2) Association can profoundly modify the properties of the 

 two organisms, the B. typhosus losing its sensibility towards 

 agglutinins and the B. coli being deprived of its specific 

 characteristics. 



(3) The colonies of B. coli in the depth of the gelatine, after 

 the third or fourth week, insensibly approach in dimensions and 

 appearance the colonies of B. typhosus. 



(4) The diminution of the vital energy of the organisms 

 shows itself not only in a diminution in the size of the colonies, 

 but also by a delay in their appearance. 



(5) If the agglutination of a bacillus, presenting the characters 

 of the B. typhosus, by an experimental anti-typhoid serum in a 

 high dilution, suffices to authorise us to consider the organism 

 as typhoid in nature, the absence of sensibility towards the 

 specific agglutinins does not permit us to reject the organism 

 from the group of typhoid bacilli. 



(6) Bacilli which possess the attributes of the B. typhosus, 

 but which are no longer agglutinated by experimental anti- 

 typhoid serum, ought to be considered as typhoid bacilli if a 

 guinea-pig, which has received every second day J2 c.c. of a 

 forty-eight hours broth culture of the organism, produces after 

 fifteen days a serum which agglutinates a tvpical B. typhosus in 

 a minimum dilution of 1-40. 



(7) There may exist true typhoid bacilli which cannot be 

 agglutinated by anti-typhoid serum, and the typhoid nature of 

 which it is impossible to determine, either by the procedure given 

 above or by the means of diagnosis actually at our disposal. 



Remy's results are very interesting, but it is strange that the 

 effects of the association of B. coli and B. typhosus were only 



