Throu 'hout this experiment there was no discoverable 

 increase in the opsonic activity of the blood against pneumo- 

 cocci. This is probably due to the fact that the initial in- 

 jection was so large as to closely approximate the lethal dose. 

 The reaction to the initial inoculation was so violent that 

 the animal lost 15,^ of its body weight in eight days. The sub- 

 sequent injections resulted in equally violent disturbances so 

 that the animal was practically in a kataphylactic state during 

 the whole period of the experiment. Yet in this weakened con- 

 dition, a state commonly characterized as "defenseless", the 



opsonic 

 blood revealed no diminution whatever in its^ activity against 



the bacteria commonly associated with terminal infections. 



In these experiments we have reviewed three types of 

 fatal pneurnococcus infections — one in vjhich the phagocytic 

 index for pnexmococcus was very high during the early stages 

 of the disease, but fell rapidly after the infection began to 

 gain on the bod^/-, and reached zero sometime before tne death 

 of the animal; in the second case there was a corresponding 

 increase in opsonins during the early stages of the infection 

 but the decrease following the break was gradual and the index 

 never at any time fell to the level of the normal; the third 

 type was one in which the character of the infection from the 

 start was so severe that there was no increase whatever in the 

 phagocytic activity above that observed in the normal. These 

 three types, however, are alike in that none shows a decrease 

 in the opsonic index for either Staph, aureus or B. coli . 

 during the period immediately preceeding death. 



(18) 



