168 G G Hedop: 



the demonstration of an existing immunity in contagious pleuro- 

 pneumonia of cattle. Only in one naturally infected animal 

 could immune bodies be detected." 8 



Panisset (1914) (15) has also published a summary of our 

 present knowledge of the filterable viruses in general, and in do- 

 ing so, has covered much of the ground covered by Meyer in his 

 review. It is interesting to note that Panisset in his summary 

 states : — " L'immunisation contre les virus filtrants ne semble pas 

 proceder des memes principes que l'immunisation contre les bac- 

 teries. Les phenomenes humoraux qui accompagnent l'etat 

 d'immunite sont peu marques (agglutination, precipitation) ou 

 manquent complement, on ne les observe bien que dans la peri- 

 pneumonie qui a beaucoup d'egards est une maladie bien dif- 

 ferenciee. Cependant la fixation des sensibilisatrices du serum 

 <est assez souvent observee." 9 



Cultures. 



The foregoing chapter is a short resume of the literature at my 

 disposal when this research work was commenced. Although it 

 seemed probable that any attempt to apply the agglutination or 

 complement fixation tests for the diagnosis of contagious pleuro- 

 pneumonia would not be successful, it was decided to proceed 

 with the research work, more especially because no such work 

 had been previously attempted in Australia. Accordingly, on 

 4/10/19, a commencement was made by obtaining virulent lung 

 serosity from a naturally infected cow which was killed at the 

 City Abattoirs, Melbourne. A small quantity of this lung serosity 

 was collected under aseptic conditions in sterile Pasteur pipettes, 

 and inoculated direct into ten tubes of Martin's peptone bouillon 

 plus 7.5 per cent, normal ox serum, and placed in the incubator at 

 37°C. A further quantity of the lung serosity from the same ani- 

 mal was collected in a sterile bottle, and brought to the laboratory. 

 This serosity was used later for an experiment to demonstrate 

 the filter-passing properties of the organism of contagious pleuro- 

 pneumonia. 



Of the ten tubes inoculated direct wjth virulent lung serosity 

 on 4/10/19, four showed obvious contamination after 36 hours' 

 incubation, and were discarded. Of the six remaining tubes one 

 proved sterile, the other five showed in from 4 to 6 days a faint 



8. P. 284. 



9. P. 312. 



