THE PHENOMENON OF AGGLUTINATION 239 



tenberg noticed that they were inherited, and this was also shown, 

 in 1908 and in 1910 by von Dungern and Hirschfeld, 56 who further 

 found that this inheritance followed the Mendelian law strictly. 

 The agglutinogens are the unit characters. The agglutinogens ap- 

 parently are present at an earlier embryonic stage than the ag- 

 glutinins. On account of their hereditary nature and permanence 

 for the individual the iso-agglutinins may possibly be of medicolegal 

 value. They may also be of some practical importance in selecting 

 donors for blood transfusion, as phagocytosis of red blood cells in the 

 circulation after transfusion, first described by Hopkins, was proved 

 by Ottenberg to occur only when the patient's serum was agglutina- 

 tive toward the donor's red cells, and several such transfusions have 

 had fatal results. Similar iso-agglutinins have been observed in the 

 blood of lower animals, in horses (Klein, 57 1902) ; rabbits (Boycott 

 and Douglas, 58 1910) ; cats (Ingebrigtsen) ; dogs, rats, and steers 

 (Ottenberg). 59 The iso-agglutinins have been developed in dog& 

 (von Dungern and Hirschfeld). 60 In most of the lower animals 

 they have occurred with peculiar irregularity, indicating probably 

 the presence of, not two, but of a larger number of agglutinins and 

 agglutinogens. In steers, however, they fall into simple groups^ 

 indicating the presence of only one agglutinin and agglutinogen. In 

 many animals the agglutinins are entirely latent, and the biochemical 

 differences represented by the agglutinogens are present in the red 

 cells, and the correct agglutinin is developed by the animal only 

 when it is immunized with blood whose cells contain agglutinogen 

 not present in the animal's own blood cells. 



The fundamental principle underlying all the Ehrlich hypotheses 

 is the conception that these reactions take place as do purely chemical 

 reactions, following the law of multiple proportions. Such reasoning 

 has often necessitated the assumption of differences of affinity which, 

 critically examined, are really ex post facto explanations, forcing 

 the phenomena to conform with the theory. As a matter of fact, 

 the bodies which participate in the antibody-antigen reactions are 

 probably of the nature of the substances which are spoken of as col- 

 loids, and it is therefore more than likely that the quantitative and 

 other relations governing the union of these reagents should be anal- 

 ogous to those governing colloidal reactions in general. The reaction 

 of agglutination, like that of precipitation, has lent itself particularly 

 to the study of the principles of the union from this point of view, 

 and the first and fundamental progress made in this direction is 

 found in the work of Bordet. 



56 Von Dungern and Hirschfeld. Zeitschr. f. Imm., 4, 1909-1910, p. 53; 

 also ibid., 1910, p. 284. 



57 Klein. Wien. kl. Woch., 1902, p. 413. 



58 Boycott and Douglas. Jour, of Path, and Bact., Jan., 1910. 



59 Epstein and Ottenberg. Tr. N. Y. Path. Soc., 1908. 



60 Von Dungern and Hirschfeld. Zeitschr. f. Imm., 1909, 1910, p. 531. 



