318 COLLECTED STUDIES IN IMMUNITY. 



Proagglutinoid. 



As a result of the brilliant investigations of Bail l on the one hand 

 and of Eisenberg and Volk 2 on the other, two new phenomena have 

 been described as occurring in the agglutination reaction, phenomena 

 which are of great importance in the study of agglutinins. Bail 

 first showed that typhoid bacilli which had been added to an inac- 

 tivated (by heat) agglutinin and then centrifuged could not longer 

 be agglutinated by the addition of active agglutinin. The study of 

 Eisenberg and Volk described an irregularity occurring in a series of 

 agglutinations which manifested itself in this, that the tubes con- 

 taining the largest amount of agglutinin showed only feeble agglutina- 

 tion or none at all, while the tubes containing less agglutinin showed 

 strong agglutination. 3 Bail was of the opinion that the phenomenon 

 observed by him was due to the interaction of two components (cor- 

 responding to amboceptor and complement), and he supported this 

 with several reactivating experiments. Eisenberg and Volk explained 

 the irregular course of the agglutination by the presence of agglutinoids, 

 a view in which I fully agree. 



Following Ehrlich's nomenclature I should, however, like to term 

 these agglutinoids 4 proagglutinoids, for we are dealing with the action 

 of substances which arise from the agglutinins as a result of external 

 influences. Furthermore the proagglutinoids possess a higher affinity 

 for the bacilli than the unchanged agglutinin, and they have lost that 

 group which is the real carrier of the agglutinating action, while the 

 other group, which effects the combination with the bacteria, is left 

 intact. 



1 Archiv. f. Hygiene, 1902, Vol. XLIII. 



2 Zeitschr. f. Hygiene, 1902, Vol. XL. 



3 This paradoxical phenomenon is mentioned by Asakawa in a report from 

 the Institute for Infectious Diseases, Tokio (Sept., 1901), and is termed by 

 him a "reversely behaving phenomenon" ("ein umgekehrt sich verhaltendes 

 Phanomen"). 



4 Since the conclusion of these experiments two new studies have appeared 

 on precipitoids. R. Kraus (Centralblatt fur Bakteriologie 1902, Vol. XXXII, 

 No. 1), v. Pirquet and Eisenberg (Extrait d. Bull. d. I'Acade'mie des sciences 

 de Cracovie, also Centralblatt f. Bakteriologie, 1902, Vol. XXXI, No. 15); 

 also Wiener (Klin. Wochenschr. 1901, Uber Precipitoide). The authors 

 arrive at the same results as have been described for agglutination. Their 

 experiments for demonstrating these precipitoids are similar to mine for the- 

 proagglutinoids. 



