THE BACTERIOPHAGE IN DISEASE 219 



Rdle of the bacteriophage in the disease 



In Cochin-China barbone is always present in sporadic form 

 causing each year numerous small epizootics which remain lo- 

 calized in individual villages. A localized epidemic observed 

 in Long Huu in the Province of Gocong may serve as an example. 



From May 5 to 13, 1920, seventeen buffaloes died: — on May 5, 

 one; May 7, three; May 8, two; May 9, one; May 10, two; May 

 11, four; May 12, three; and May 13, one. Then the epizootic 

 stopped and not a single case was detected during the next six 

 months. 



Specimens of the feces of four of these animals were collected, 

 either before death or from the cadaver. None contained a bac- 

 teriophage active for the bacterium of barbone. On May 13 

 specimens of feces were collected from healthy animals, as follows: 



First. From a buffalo in a stable where two animals had 

 died, one on May 12, the other on May 13. 



Second. From three buffaloes in a stable where one had died 

 on May 5. 



Third. From two buffaloes in a stable where two had died, 

 one on May 8, the other on May 11. 



Fourth. From four buffaloes in a stable which had not been 

 invaded. 



Fifth. From one buffalo, living alone in a stable located at 

 a distance of about five kilometers from the village of Long Huu. 



Sixth. From eight buffaloes in the surrounding villages, from 

 eleven to nineteen kilometers distant. 



Of all the specimens, those in the first, second, third and fourth 

 groups gave a bacteriophage of weak or average activity (-f or 

 ++) for the bacterium of barbone. An active bacteriophage 

 was not found in the specimens from groups 5 and 6. 



Again on May 19 specimens were collected in Long Huu, as 

 follows: 



First. From the buffalo which had furnished specimen no. 1 

 on May 13. 



Second. From two buffaloes living in a stable where three 

 had died from May 7 to May 12. These specimens all gave a 

 bacteriophage moderately virulent (++) for the bacterium of 

 barbone. 



