BACT. PERTUSSIS AND B. BRONCHISEPTICUS 207 



Two rabbits, more responsive to vaccines, developed, after a few 

 inoculations, a comparatively high agglutination titre — up to 1000. 



6. Sera from rabbits treated wtih BacL pertussis grown on blood 

 media developed marked agglutinins for Bad. pertussis grown 

 on plain agar. 



This is contrary to Bordet's statement that animals inoculated 

 with Bad. pertussis grown on Bordet-Gengou medium develop 

 agglutinins for Bad. pertussis grown on the same media, not for 

 the organism grown on plain agar; and is in accordance with 

 Povitzky's and Worth's conclusion that, 



From our experience it would seem that the culture medium influ- 

 ences an agglutinable strain in so far as it affects its growth and best 

 development, not in its production of different kinds of agglutinins. 



Also, serum from a rabbit treated with Bad. pertussis no 

 0363 (Bordet) grown on ascitic agar for the past three years 

 agglutinates all thirteen strains grown on blood media (with only 

 one generation, for suspensions, on plain agar); and sera from 

 rabbits treated with thirteen strains grown on blood media 

 agglutinate the ascitic agar strains. 



7. When B. hronchisepticus antiserum is absorbed with B. 

 bronchisepticus sufficiently to remove the agglutinins for B. 

 hronchisepticus, the agglutinins for Bad. pertussis are still un- 

 affected. These unaffected or fixed agglutinins have been called 

 by the writers, transitive agglutinins. 



Upon repeated absorption, agglutinins for Bad. pertussis have 

 been removed by the dog strain of B. bronchisepticus, slightly 

 reduced by the monkey strain and affected not at all by the 

 human strain. 



It may be that, by the absorption tests, grades of differences 

 are brought out between B. bronchisepticus from dog, monkey 

 and human which are not shown in the agglutination tests. A 

 similar differentiation is thought to have been brought out by 

 complement fixation tests. (See article in press by Ferry and 

 Klix). 



