Pleuro-Pneumonia of Cattle. 1 87" 



Antigen C. — A third subculture, 14 days old, in Martin's broth- 

 horse serum. (Primary culture in Martin's broth ox serum, 

 first and second subcultures in Martin's broth horse serum.) It 

 was markedly anticomplementary in quantities of 0.25 c.c. of 

 a 1 in 10 dilution, but gave no inhibition of haemolysis in quan- 

 tities of 0.15 c.c. of a 1 in 10 dilution. 



Antigen D. — A divalent antigen. A mixture of a third sub- 

 culture 8 days old, and a second subculture 10 days old, from 

 two separate sources. Both cultures were grown in Martin's 

 broth plus ox serum. Not anticomplementary in quantities of 

 0.25 c.c. of a 1 in 10 dilution. 



Antigen E. — A 28 days old culture (filtration experiment) in 

 Martin's broth ox serum. Not anticomplementary in quantities 

 of 0.2 c.c. of a 1 in 10 dilution. Slight inhibition with 0.25 c.c. 

 of the same dilution. 



Antigen F. — Lung serosity from an active case of contagious 

 pleuro-pneumonia. Very anticomplementary in all quantities of 

 a 1 in 10 dilution. 0.5 c.c. of a 1 in 20 dilution in saline showed- 

 no inhibition of haemolysis. 



Antigen G. — Oedematous fluid from the zone of inoculation 

 behind shoulder (Experimental Cow 4), taken 16 days after in- 

 oculation. Not anticomplementary in quantities of 0.3 c.c. of a 

 1 in 10 dilution. 



Antigen H. — A polyvalent antigen made up of four strains of 

 culture in Martin's broth ox serum. (One culture 8 days old;: 

 one culture 14 days old; one culture 16 days old; and one culture 

 21 days old). Culture mixture not anticomplementary in quan- 

 tities of 0.25 c.c. of a 1 in 10 dilution. 



Antigen J. — Concentrated culture in Martin's broth plus ox 

 serum, concentrated by evaporation (vide supra). 



Complement Fixation Tests with Pure Culture. 



These various culture preparations were tested for comple- 

 ment fixation with known positive and negative sera. A num- 

 ber of tests were conducted with each antigen preparation, but 

 in every case the test showed that the antigen plus positive serum 

 combination did not fix complement; the final result in all such- 

 cases being complete haemolysis Antigen plus negative serum 

 gave complete haemolysis also ; thus, complete haemolysis took 

 place irrespective of whether the serum used was obtained from 

 a positive or negative source. 



