Through the painstaking researches of a great number of workers, we have come into possession of much information concerning the action of foreign protein when injected into animals subcutaneously, intraperitoneally or intravenously. The forms of protein most carefully studied are those of the various serums and the incentive for this study had its origin in the revolutionary discoveries of von Behring, Ehrlich, Wassermann, Abderhalden, Wright, Vaughan and a host of other workers. The study of the protein of the various serums led naturally to the study of the protein of the common food products, and out of this has come a great mass of information concerning the protein of milk, egg, meat and cereals. The leaders in the researches are Besredka, Vaughan, Osborn, Anderson and many others. Out of the tremendous amount of work which has been done in an effort to explain the phenomenon of anaphylaxis there have accumulated