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N. S. FERRY AND ARLYLE NOBLE 



been transplanted daily for several days before using so that very heavy 

 growths were obtained. 



Absorption tests. Equal parts of heavy suspension and serum were 

 mixed; incubated at 37°C.; then centrifugalized and the supernatant 



TABLE 6 

 Absorption tests with B. bronchisepticus and Bact. pertussis antisera 



fluid tested for agglutinins. The time of incubation, the number of 

 absorptions and the dilution of the serum were varied in a number of 

 ways. For example, we found that when either antipertussis or anti- 

 bronchisepticus serum was diluted to 1-40, we obtained a more nearly 



