STUDIES ON FOWL CHOLERA 291 



CONCLUSIONS 



These results of the agglutination tests appear to substantiate 

 the results of the cultural tests in demonstrating that Dr. Bull's 

 culture was a strain of the fowl typhoid bacterium and not a 

 repre-entative of the fowl cholera or hemorrhagic septicemia 

 group. The facts that cultures of the fowl cholera bacterium are 

 non-toxic, and that they are not opsonized into phagocytosis, 

 therefore remain uncontroverted so far as Dr. Bull's experiments 

 are concerned. Indeed Tchistovitch (1909) appears to have 

 demonstrated that, in the case of the actual fowl cholera organ- 

 ism, serum from the dog did not assist the rabbit leukocytes to 

 ingest the fowl cholera organisms. Notwithstanding this cir- 

 cumstance, however, Dr. Bull's study of phagocytosis in reference 

 to the culture used by him, if properly interpreted, adds much to 

 our knowledge of the toxicity, opsonins and phagocytosis of one 

 of the most interesting and slightly studied types of the colon- 

 typhoid intermediates. 



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