STUDIES ON FOWL CHOLERA 289 



fowl cholera and a member of the hemorrhagic septicemia 

 group. B. avisepticus does not ferment most of the carbohydrates 

 ordinarily used in bacteriological work; and it leaves litmus milk 

 quite unchanged after a period of ninety days at 37°C. 



Agglutination tests. In view of the fact that fowl cholera 

 immune serum seldom if ever agglutinates completely (in vitro) 

 its homologous antigen in dilutions greater than 1 : 160, the 

 specific agglutination test is obviously of slight value in testing 

 a questionable strain. It is necessary to demonstrate an affinity 

 or lack of affinity with other immune sera. Since the majority of 

 so-called fowl cholera cultures maintained in the laboratories of 

 this country are not B. avisepticus but Bad. gallinarum (E. Klein), 

 or some other member of the colon-t5rphoid intermediates, Dr. 

 Bull's culture was first tested against sera immune to the bacillus 

 of fowl typhoid. Since the laboratory collection of immunized 

 animals contained rabbits immune to two fowl typhoid strains 

 obtained from Dr. Theobald Smith, these, among others, were 

 employed for the tests with results as shown in the following table. 



From a study of the agglutination features a ^ presented in the 

 table it appears that there was present a satisfactory agglutina- 

 tion affinity between all of the sera immune to the fowl typhoid 

 strains (Bad. gallinarum) (115, 116, 102A« and 118«) and Dr. Bull's 

 culture, but none with Bad. avisepticus antigen. Moreover, that 

 serum immune to B. avisepticus while agglutinating its homo- 

 logous antigen at §, 4 m, failed to agglutinate Dr. Bull's cul- 

 ture in any significant dilution. 



THE JOURNAL OF BACTERIOLOGY, VOL. Ill, NO. 3 



