BACTERIAL PROTEINS 29 



action does not disrupt the living bacterial cell. 

 (2) Thoroughly washed typhoid bacilli are not 

 agglutinable. (3) When typhoid bacilli are 

 thoroughly shaken in salt solution so as to re- 

 move their flagellse and the bacilli are deposited 

 in a centrifuge, the emulsion of flagellae is ag- 

 glutinable. (4) Neufeld has shown that when 

 cholera bacilli are thoroughly cleansed by be- 

 ing shaken with one per cent alkali, which does 

 not destroy them and only washes away adher- 

 ent matter, they are not inagglutinable but pro- 

 duce no agglutinin when injected into animals. 



Agglutination and precipitation are closely 

 related phenomena. When a bacterial culture 

 is filtered, some of the proteins about the cells 

 pass into solution and constitute the precipito- 

 gen while some of the same class of near-cell 

 proteins remain adherent to the cells and consti- 

 tute the agglutinable substance or the agglutin- 

 ogen. 



I find that the bacterial cellular substances on 

 standing undergo autolytic cleavage. We are 

 just now examining a bottle of colon cellular 

 substance which was prepared ten years ago. 

 It was only air dried and contains a small 

 amount of moisture. When freshly prepared 

 water or salt solution extracted no protein, now 



