PATHOGENIC BACTERIA. 



305 



phoid fever, within a few minutes the motility of the typhoid 

 bacilli is abolished and they become agglutinated into 

 clumps or masses. Occasionally the bacilli may eventually 

 undergo disintegration into granular material. This re- 

 action does not take place with the blood-serum of healthy 

 persons or of those suffering with other diseases, nor when 

 the blood-serum of a typhoid fever case is mixed with motile 

 bacteria other than typhoid bacilli. It has been observed 

 in the blood-serum of an infant born while the mother was 

 convalescing from typhoid fever. 



FIG. 87. 



Application of the serum-reaction to typhoid bacilli. A shows the dis- 

 tribution of the bacilli before the reaction. It is to be remembered that 

 they are motile and their positions may change continually. B shows 

 clumping of the motionless bacilli after mixture with the serum of a case 

 of typhoid fever. Diagrammatic. 



The agglutinating substance has been found in blister- 

 serum and in the milk of typhoid cases, in fluids from the 

 serous cavities and inflammatory and edematous areas in 

 variable amounts, and occasionally in urine, bile and tears. 



The reaction may be obtained by adding blood-serum to 

 a young bouillon-culture of typhoid bacilli kept in the in- 

 cubator, when the occurrence of agglutination becomes 



