222 GERMICIDAL SERA 



enzyme appears in the spleen first, and within twenty-four hours after 

 the inoculation. The bacteriolytic titer of the spleen extract increased 

 before that of the circulating blood. However, it must not be inferred 

 that the spleen is the only organ in which the specific enzyme is 

 formed. It is possible that many of the cells of the body are capable 

 of performing this function and that an organ specially active in 

 resisting one infection may play a subordinate role in another. Heck 

 made a comparative study of the persistence of the typhoid bacilli in 

 various organs of normal and immunized animals after intravenous 

 injections. In the normal animals, they were not found in the circu- 

 lating blood after six hours; were present in the kidneys and lungs 

 up to the third day; in the liver after the fifth day; in the spleen 

 after the twentieth day and in the bone marrow up to the sixtieth 

 day. In immunized animals, they disappeared first from the spleen 

 and bone marrow, and all organs were sterile on the third day. 



The constitution of the specific bacteriolysins is similar to that of 

 the non-specific in normal blood. They consist of alexin or complement 

 and fixator or amboceptor. Their specificity lies in the amboceptor 

 and it is this which combines with, or acts on, the bacterial cells. 

 PfeifTer describes the action of a highly immune serum on its homol- 

 ogous bacterium as follows : "The micro-organisms first lose their 

 motion, then swell and finally contract into balls, in which some motion 

 may be still seen, showing that living bacilli are being dissolved. For 

 a time the granules seem like micrococci and can be stained. They 

 gradually grow smaller and smaller and finally dissolve in the fluid 

 just as sugar or salt dissolves in water." 



