IMMUNITY REACTIONS WITH AMCEB^. 295 



selected should have reacted in absolutely different manners, not even 

 group reactions being present. In Table V, the serum of race A ap- 

 parently shovp-ed some activity against race D. Here it v?as thought that 

 perhaps only a relative difference existed between the activity of serum A 

 for amoebge A and D, but subsequent tests did not confirm this view. In 

 Table VI the difference is absolute and this result was confirmed by two 

 subsequent tests. This behavior of the sera corresponds with the results 

 obtained by Eossle(9) who found that the sera produced by paramcecia 

 are also specific. 



The specificity of the sera for the corresponding cultures affords addi- 

 tional evidence that the injections of the amcehse were responsible for the 

 activity of the sera, since it was possible for the amcebse to vary in each 

 culture, but the bacterial species, B. prodigiosus^ was common to all. If 

 any activity of the antibacterial serum against the B. prodigiesus, in the 

 symbiotic culture of amcebae and bacteria could have affected the growth 

 of the amoebae, then this effect should have shown itself in all four cultures. 



A note on the morphology of these cultures is of interest in view of 

 the biologic differences which were found. Dr. B. L. Walker of the 

 biological laboratory. Bureau of Science, has very kindly examined these 

 cultures and describes them as being readily distinguishable from each 

 other on a morphologic basis, however all correspond to the Umax type. 



EEACTIOlSrS WITH SERA FROM DYSENTERIC PATIENTS. 



The interpretation of these biologic differences requires some caution. 

 Many possibilities present themselves in view of the failure of these amcebse 

 to fall into groups according to the source from which they were obtained. 

 Thus any of these amoebaB may be pathogenic or any may be harmless. In 

 the case of the cultures obtained from dysenteric faeces, it is possible 

 that the pathogenic species may fail to grow on artificial media and the 

 organism which does develop may be merely an accompanying saprozoite. 



Accordingly, in an attempt to determine whether these amcebse bear 

 any setiologic relationship to amoebic dysentery, these four races were 

 tested against the sera of amoebic dysentery patients. In considering the 

 possibility of the formation of immune bodies during the course of the 

 disease it is of some interest to note whether there is any indication of 

 the absorption of toxic products from the intestine which might serve as 

 antigen. In the first jjlaee, it is note-worthy that there is some op- 

 portunity for such absorption since the amcebge penetrate deeply, in large 

 numbers, into the submocosa of the intestine. Second, changes in the 

 formed elements of the blood are known to occur, a leucocytosis sometimes 

 being present involving not only the polymorphonuclear neutrophiles 

 but in some instances the mononuclear neutrophiles and the eosinophiles 

 as well. Also, in severe infection some fever is often present. Perhaps 

 the most favorable cases for the absorption of antigen and the production 



