AGGLUTINATED TYPHOID BACILLI. 153 



than do those which do not normally possess agglutinins has not 

 been confirmed, for out of seven animals (Table VI) in whose serum no 

 typhoid agglutinin could be demonstrated previous to treatment, 

 three did not react to the injection of agglutinated typhoid bacilli, two 

 reacted feebly and two very distinctly. On the other hand, out of three 

 animals in which, previous to treatment, a typhoid agglutinin could 

 be demonstrated, two reacted distinctly to the injection of agglutinated 

 bacilli and one not at all. 



Another assumption was, that in the animals which had reacted 

 but feebly or not at all, an increase of the sensitiveness against agglu- 

 tinated bacilli could be brought about artificially by repeated injec- 

 tions of agglutinated bacilli. This also has not been confirmed. 

 Thus three animals (Table VII) reacted to the second injection of agglu- 

 tinated bacilli just as little as they did to the first, one animal reacted 

 feebly, as it had done previously, and only two animals (Nos. 131 and 

 133), which had failed to react to the first injection, reacted distinctly 

 to the second. The protocols of these last two animals, however, point 

 out a peculiarity. On the first occasion these animals were injected 

 intraperitoneally and it is noted that at this time the intestine was 

 pricked. The first injection may therefore have mostly gone into 

 the bowel and so produced no effect. The second injection would 

 then have really been the only effective one. These two cases can- 

 not therefore be used to prove that by means of a previous injection 

 of agglutinated bacilli an artificial increase of the sensitiveness against 

 a subsequent injection of agglutinated bacilli can be effected. The 

 previous injection of agglutinated bacilli, however, in no way influences 

 the sensitiveness against non-agglutinated bacilli, as is shown by 

 the four control animals (Table VII). 



Finally experiments were made regarding still another assump- 

 tion. It was conceivable that the previous injection of a certain 

 amount of non-agglutinated bacilli would have sufficed to bring about 

 a sensitiveness against a subsequent inoculation with agglutinated 

 bacilli. This assumption also has not been borne out. Out of five 

 animals (Table VIII) which, after a previous injection of non-aggluti- 

 nated typhoid, received an injection of agglutinated typhoid, two 

 showed a slight increase and three no increase in agglutinating value. 



It follows from all these experiments that there is a distinct dif- 

 ference between the injection of agglutinated and of non-agglutinated 

 typhoid bacilli. The injection of non-agglutinated typhoid bacilli 

 is always followed by an increase of the agglutinating power. This 



