the name of anaphylatoxins legitimately, for there is no cloud regarding their origin. Such substances, with such a pedigree, have not been isolated so far. With these properly identified anaphylatoxins no confusion will be produced, for they will cause a true anaphylaxis, and the usual conception of this process will not be obscured, but, on the contrary, clarified.
This question of the causal relationship between proteid cleavage products obtained in vitro, and the symptoms and signs of true anaphylaxis has been discussed at some length because this view-point of the problem enjoys great favor; because it was necessary to point out that this view as formulated at present leads to confusion, to the useless sacrifice of a well-defined symptom complex and its characteristic anatomical and functional signs, and finally because this view is not the necessary and inevitable consequence of the experimental data at hand.
Other Manifestations of Anaphylaxis. Serum Disease.—The description given so far has dealt exclusively with the experimental analysis of the more important anaphylactic phenomena in lower animals. But similar phenomena occur in man and these have been extensively studied. Opportunity for this study was afforded shortly after therapeutic sera were generally employed to combat disease, especially diphtheria. To v. Pirquet, associated in his earlier work with Schick, we owe the most thorough study of some of the reactions which the human organism may show when injected with various kinds of therapeutic sera. These reactions v. Pirquet and Schick called serumdisease. The development and course of this serum disease is as follows. The first injection of a therapeutic serum, usually obtained from an immunized horse, is tolerated by most individuals without any reaction. In those that do react, the symptoms do not develop at once, but after the lapse of eight to ten days. The chief disturbances which now occur are fever, skin eruptions, swelling of the lymph glands near the site of injection, pains in the joints and muscles and edema of the face and dependent portions of the body. In spite of this apparently formidable list of ailments the general condition of the patient is excellent, as a rule, and there is but slight danger.
When the same patient is reinjected after an interval of more than ten days, the picture is somewhat different. The period of incubation is practically absent or at least considerably shortened, and the symp-
- It must be stated at once that these undesirable accessory reactions which sera sometimes show in the human being form no contraindication to their employment in proper cases. In severe diphtheria, for example, the antidiphtheritic serum is the only remedy which can save the patient from death; to hesitate in its employment because it may produce more or less severe symptoms itself, would be criminal, as this action might be equivalent to throwing away the only chance of recovery the patient has.