402 BIOLOGY OF PNEUMOCOCCUS 



after crisis or lysis, it lacked the property in the great majority 

 of instances where the patient had died of the disease. The height 

 of bacteriotropic activity of the serum of pneumonia patients was 

 found by Adler (1923) 3 to occur at the time of crisis. 



THE MECHANISM OF PHAGOCYTOSIS 



The factors and processes involved in the response of rabbits to 

 intravascular injection of pneumococci were investigated by Kita- 

 gawa (1915). 717 When the living organisms were injected directly 

 into the blood stream of rabbits there was an immediate, initial 

 drop in the count of circulating cocci, followed by either a slow 

 increase or decrease in number depending upon the dosage and viru- 

 lence of the injected culture. When similar injections were made 

 into actively immunized rabbits, the cocci disappeared with great 

 rapidity from the circulation, the blood usually becoming sterile 

 within ten minutes after the injection. Kitagawa concluded that 

 the speedy disappearance of the injected pneumococci from the 

 blood stream of actively immunized rabbits was not due to destruc- 

 tion of the organisms by plasma or leucocytes, but rather to their 

 mechanical removal or destruction by the fixed tissues. Kline and 

 Meltzer (1915) 727 also noted that pneumococci promptly vanished 

 from the pneumonic lung of dogs infected by intrabronchial in- 

 sufflation after previous repeated intravenous injections of pneu- 

 mococci. 



The same phenomenon was studied by Winternitz and Kline 

 (1915). 1522 In normal rabbits the reaction to inoculation was im- 

 mediate and the ultimate result was bacteriemia and death ; in pas- 

 sively immunized animals the organisms rapidly disappeared from 

 the blood and recovery took place; in rabbits previously rendered 

 aplastic with benzol and then injected with specific immune serum, 

 there was an immediate effect on the injected pneumococci, but 

 bacteriemia recurred and death ensued; in actively immunized, 

 aplastic rabbits, the initial reaction was the same as in the pas- 

 sively immunized, aplastic rabbits, but the actively immunized, 



