BACT. PERTUSSIS AND B. BRONCHISEPTTCUS 



205 



complete absorption than when diluted 1-10, which may be due to the 

 fact that complete agglutination does not occur in the lower dilutions 

 with either of the organisms, especially with Bod. pertussis. And in the 

 absorption tests, it was noted that clumping and clearing was not so 

 complete at 1-10 or 1-20 as at 1-40. 



Again, serum from rabbit 5, treated with B. bronchisepticus (Human) 

 was absorbed as many as four times, the dilutions being from 1-5 to 

 1-40 and the tests being shaken in a mechanical shaker before each 

 incubation, with no effect on the agglutinins for Bad. pertussis. 



It was found that when antibronchisepticus serum was absorbed with 

 B. bronchisepticus sufficiently to remove the agglutinins for B. bronchi- 



TABLE 7 

 Absorption tests with serum from distemper dogs 



septicus the agglutinins for Bact. pertussis were still unaffected. This 

 could be done by an absorption at 1-40, incubated 24 hours. Table 5 

 gives the results of such an experiment. 



But it required repeated absorption with B. bronchisepticus 

 before any marked effect was produced in the pertussis agglu- 

 tinins, and this happened only with the dog strain. 



Finally, the following method was used with the six antibron- 

 chisepticus sera. The results of these experiments are given in 

 table 6. 



Each serum was absorbed three times with its homologous 

 antigen — that is, serum from rabbit treated with B. bronchi- 

 septicus (dog) was absorbed with the dog strain — and with 

 pertussis antigen as follows: 



