1917] VETERINARY MEDICINE. 579 



equimcm), dourine (T. equiperdum) , nagana {T. brucei), and the nonpatho- 

 genic trypanosome, T. leivisi. The anaphylatoxin was made not only by the 

 living cells but also by those dead and more or less autolyzed, and even by 

 those heated to 60° C. The same mass of trypanosomes could be used repeatedly 

 to toxify different lots of serum. Rat serum was found preferable to guinea 

 pig serum since it yielded a poison 12 or more times as active as that obtained 

 with the latter, the lethal doses being 0.25 cc. and 3 cc, respectively. 



" The speed of poison production under favorable conditions is very rapid 

 and quickly reaches a maximum, the poison then persisting for a long time. 

 Thus, infected, defibrinated rat blood or serum, when incubated for one or two 

 minutes, may become fatally toxic. With an incubation of about 15 minutes 

 it is possible to produce a toxic serum such that 0.25 cc, will cause acute 

 anaphylactic death." The anaphylatoxin was found to persist at 37° for more 

 than four hours and at about 0° for an indefinite time. 



" Toxic sera can induce toxicity in normal sera, the mixtures representing a 

 high dilution of the former. This result is not due to the action of a ferment, 

 but to minute amounts of trypanosomes still present in the inciting serum ; or, 

 in the case of very prolonged incubation, to the production of autoanaphyla- 

 toxin. . . . 



" Transfusion experiments indicate the possible presence of anaphylatoxin in 

 heavily infected rats. The formation of this poison in corpore may lead to 

 sudden deaths or to chronic intoxication or cachexia. . . . 



" The injection of large amounts of washed trypanosomes into guinea pigs 

 may result in the production of anaphylatoxin in corpore. The effects are not 

 due directly to the organisms but to the disturbance in the colloidal state of 

 plasma constituents caused by the alien material. The ' trypanotoxins ' are 

 therefore disturbers of equilibrium ; the result is a poison production in vivo 

 as well as in vitro. The mode of action of endotoxins in general will be found 

 to be of the same nature. 



" The participation of a ferment in this reaction is contraindicated by the 

 speed of production, the rapid attainment of maximal level, the behavior of 

 inactivated sera, and by the results of centrifugation. 



" The syndrome of symptoms and autopsy findings consequent on the injection 

 of the trypanosome anaphylatoxin are those of the intoxication of true anaphy- 

 laxis. The two poisonings are to be considered as identical." 



II. Agar anaphylatoxin: Guinea pig serum, F. G. Novy and P. H. DeKruif 

 (pp. 536-565). — Anaphylatoxin was produced in guinea pig scrum by using agar 

 in place of the trypanosomes. Incubation from 8 to 10 minutes at 37° was 

 found to render the serum fatal in a dose of 3 cc. The lethal dose can be re- 

 duced to 1 cc. " The toxicity of such serum, when tested at regular intervals, 

 appears to show more or less oscillation, as in the case of the trypanosome 

 anaphylatoxin. Such variations are not due to a change in the amount of the 

 poison, but to a varying resistance of the test animals. The physical state of 

 the agar is an important factor in the production of the poison." 



Incubation at 37° is necessary, and serum contact does not result in poison 

 production, which contraindicates absorption as a factor in the reaction. In- 

 dividual variation in the ease with which sera can be toxified was noted. 



III. Agar anaphylatoxin: Rabbit serum, F. G. Novy and P. H. DeKruif (pp. 

 566-588). — The production of anaphylatoxin in normal rabbit serum was found 

 not to be as easy as in the case of guinea pig or rat serum. Individual varia- 

 tion in the ease with which the serum yielded the poison was again observed. 

 The presence of lipoidal matter was not found to be inhibitive. After a short 

 fast the sera appeared to be more reactive, and a varied diet was favorable to 



