246 



COLLECTED STUDIES IN IMMUNITY. 



TABLE I. 

 HAEMOLYSIS OP GOAT BLOOD (1 cc. 5%) BY FRESH SERUM OF NORMAL RABBITS. 



HAEMOLYSIS OF GOAT BLOOD BY THE SAME RABBIT SERA ACTIVATED WITH 



0.15 GUINEA-PIG SERUM. 



HAEMOLYSIS OF Ox BLOOD BY THE SAME RABBIT SERA ACTIVATED WITH 



0.15 GUINEA-PIG SERUM. 



The fresh rabbit sera, even in amounts of 0.5, do not by themselves exert any hsemolytic 

 effect on ox blood. 



vation was effected by the addition of normal guinea-pig serum. 

 The hsemolytic action of the immune sera is seen in Table II. 



Rabbits were treated with goat serum which had been carefully freed from 

 all blood-cells by continued centrifuging. Usually the serum was inactivated 

 by heating it to 55 C. for half an hour, then it was injected intraperitoneally. 

 As a rule the animals received two to three injections of increasing doses of serum, 

 in all about 35-90 cc. More frequent injections caused no greater formation 

 of amboceptors, a behavior which corresponds to that seen with the injection 

 of ox blood or goat blood. 



These experiments show that specific amboceptors were developed 

 in all the rabbits treated with goat serum. Quantitatively this was 

 subject to individual fluctuations just as is seen following the injec- 

 tion of blood-cells; in some cases the development was quite con- 

 siderable. Most of the sera were examined fresh for their action on 

 ox blood, and invariably showed themselves without action even in 

 doses of 0.5 cc. 1 The addition of large amounts of normal rabbit 



l The method here employed to disclose amboceptors whose presence is 

 masked can often be used with success. Dr. Marshall and I shall shortly report 

 an analogous case dealing with the amboceptors of a pathological exudate. 



