Pleuro- Pneumonia of Cattle. 



195 











See 



IES B. 











0) 



6 

 ■eg 



40 

 C 

 V 



E . 



g = 

 62 



© 



So 



sctf 



Degree 



of Haemolysis after 

 at 37°C. for 



incubation 



2 



H 



Half hour. 





One hour. 





Two hourn. 



1 



- 15 - 



•5 - 



1-85 - 



•5 - 



Complete 



- 



Complete 



. 



Complete 



2 



- -15 - 



•45 - 



1-9 - 



•5 - 



»j 



• 



„ 



- 



,, 



3 



- -15 - 



•4 - 



195 - 



5 - 



»> 



- 



,, 



- 



,, 



4 



- -15 - 



•35 - 



2- - 



•5 - 



,, 



- 



>j 



- 



>> 



5 



- 15 - 



•3 - 



205 - 



5 - 



„ 



- 



„ 



- 



>> 



^ 



- 15 - 



■25 - 



21 - 



•5 - 



Partial 



- 



f> 



- 



» 



7 



- '15 • 



•2 - 



215 - 



5 - 



Slight 



- 



,, 



- 



„ 



8 



- 15 - 



•15 - 



2-2 - 



•5 - 



Slight 



- 



Partial 



- 



,, 



9 



- 15 - 



1 - 



2 25 - 



5 ." 



Very slight 



Slight 



- 



,, 



10 



- 15 - 



•05 '- 



23 - 



•5 - 



None 



- 



Slight 



- 



A lmost 

 complete 



11 



- 15 - 



— - 



235 - 



•5 - 



None 



- 



None 



- 



None 



12 



— - 



— - 



25 - 



•5 - 



None 



- 



None 



- 



None 



The results in series B, read after incubation for half an hour, 

 were almost exactly similar to the haemolytic results obtained 

 with series A, after incubation for half an hour. In series B, 

 "however, the sensitised red blood cells were energetically con- 

 glutinated shortly after they were added. After incubation for 

 -one hour, series B showed complete haemolysis in tubes 1 to 7, 

 and varying degrees of haemolysis in tubes 8, 9, and 10. At the 

 end of two hours' incubation haemolysis was complete in tubes 

 1 to 9, while in tube 10 haemolysis was almost complete. 



It is thus evident that the influence of conglutinin upon a small 

 amount of complement is such that in the complement fixation 

 test for contagious pleuro-pneumonia, it enables haemolysis to 

 occur with a smaller quantity of complement than the ordinarily 

 titrated M.H.D. 



If we critically examine the figures revealed by the foregoing 

 experiment, it is at once apparent that the presence of con- 

 glutinin in the bovine test serum introduces a factor into the 

 complement fixation test in contagious pleuro-pneumonia, which 

 factor, if not properly controlled, would render the test abso- 

 lutely unreliable for diagnostic purposes. 



It has been shown in this experiment that it requires 0.25 c.c. 

 •of complement dilution to completely haemolyse one unit of sen- 



14A 



