580 EXPERIMENT STATION RECORD, [Vol.37 



the reaction. The results were similar to those noted in the case of the guinea 

 pig serum. 



IV. Agar anaphylatoxin: Rat serum, F. G. Novy and P. H. DeKruif (pp. 589- 

 617).— "Rat serum can be toxifled with agar in 7.5 minutes so that 0.25 cc. 

 will cause acute fatal shock; after incubation for only 2.5 minutes 1 cc. may 

 be fatal. The reaction concerned in the production of anaphylatoxin is one 

 of great speed. Agar and trypanosomes can work at the same speed since they 

 can toxify 1 cc. in 2.5 minutes. 



" The individual sera show some variation in the ease with which they can 

 be toxified. This is not due to the age of the serum or to the presence of 

 lipoids. Normal rat serum, without any addition, on long incubation may 

 become toxic so that 1 cc. will be fatal. 



" The physical state of the agar is an important factor in the production of 

 the poLson. Its inducing power is not affected by sterilization at 140°." 



The poison is not destroyed when kept at 56° for 24 hours, but is partially 

 destroyed in half an hour at 70°, and apparently completely in 5 minutes at 

 100°. 



V. Effect of 7nultiple doses of anaphj/latoxin, F. G. Novy and P. H. DeKruif 

 (pp. 618-628). — Rat anaphylatoxin, in amounts representing from 1 to 40 lethal 

 doses, invariably produced death in guinea pigs in essentially the same time. 

 " The larger doses gave an intense quiet shock ; the autopsy findings in all 

 cases were typical, but with larger doses the petechias in the lungs were most 

 pronounced ; the blood was always free from clot. The blood when transferred 

 to a test tube showetl delay in coagulation. Slow injection of very large doses 

 gave an almost incoagulable blood. The in vitro mixtures of rat anaphylatoxin 

 and normal blood likewise showed retarded coagulation. The white rat pos- 

 sesses a remarkable immunity against anaphylatoxin ; weight for weight it 

 can tolerate more than 100 times as much as the guinea pig. The dosage with 

 serum reached 10 per cent of the body weight. . . . 



" The rabbit like the rat is not affected by large doses of anaphylatoxin and 

 this fact parallels the behavior of rabbits on injection of large doses of the 

 toxic antisheep immune rabbit serum. It is this tolerance of the rabbit for 

 the poison that permits the formation of large amounts of anaphylatoxin dur- 

 ing life. Antisheep guinea pig serum is not toxic since the formation of ana- 

 phylatoxin to the extent of a single lethal dose would mean the death of the 

 animal. This tolerance likewise accounts for the known resistance of the 

 rabbit to specific anaphylaxis." 



A transfusion experiment indicated the rapid disappearance of the anaphy- 

 latoxin from the blood. 



VI. Effect of intravenous injections of agar, F. G. Novy and P. H. DeKruif 

 (pp. 629-656). — Agar injected into guinea pigs may produce a typical anaphy- 

 lactic shock and death with characteristic autopsy findings. The rabbit 

 appears to be somewhat less susceptible than the guinea pig to the agar Injec- 

 tions and the rat still less inactive. " With a transfer time of 1 minute, the 

 transfusion of 4 cc. of normal rat blood resulted in typical fatal anaphylactic 

 shock, due to the anaphylatoxin formed as the result of the precoagulation dis- 

 turbance. 



" The transfusion method has shown that the blood of normal untreated 

 rabbits may be toxic in dose of 2 cc, and that the serum from such animals 

 may be fatal in dose of 1 cc. The apparently healthy rabbit may carry 50 

 guinea pig lethal doses per kilogram. 



" This inherent or acquired toxicity is to be correlated with that developed 

 by immunizing injections, also with the precoagulation toxicity, and with that 



