244 THE BACTERIOPHAGE 



recovered and the epizootic stopped abruptly and definitely on the same 

 day as the immunization. 



Barnyard 2. The epizootic began on about August 20. By October 6, 

 120 of 200 fowls had died. The 80 survivors, of which 7 were sick, received 

 an injection of the antigallinarum bacteriophage. The 7 recovered; the 

 epizootic immediately and permanently disappeared. 



Barnyard 3. The epizootic began October 10. By the 15th, 21 fowls had 

 died. The 130 that were alive, of which 8 were already sick, were inocu- 

 lated. The 8 recovered and the epizootic disappeared from the day of the 

 inoculation. 



Barnyard 4- The epizootic began on about November 15. By December 

 1, 26 of 51 fowls were dead. The 25 survivors, among which were 4 which 

 were infected, were inoculated. One of the sick animals died, the other 

 3 recovered. The mortality stopped from the date of the inoculation. 



Barnyard 5. The epizootic began about November 25. By December 

 1, 7 of 60 chickens had succumbed. The 53 survivors were inoculated. Of 

 these 4 were sick. The sick animals recovered and no new cases appeared. 



Barnyard 6. The epizootic began on December 16. On the 28th, 40 of 

 142 fowls had died. The 102 survivors, of which 3 were infected, were in- 

 oculated. The sick recovered and the disease abruptly stopped. 



Barnyard 7. The epizootic began on January 2. By January 14, 15 

 of 50 animals had died. The 35 survivors were inoculated. No new cases 

 developed from this time on. 



Barnyard 8. The epizootic began on about January 15 with a daily 

 mortality of 4 to 6 fowls. On January 21 the 121 survivors, including 5 

 which were sick, were inoculated. The sick recovered and the epizootic 

 stopped at once. 



Barnyard 9. The epizootic began on about February 10. By February 

 20, 14 chickens had died from among the original 84. The 70 survivors were 

 inoculated and the disease disappeared at once. 



Barnyard 10. The epizootic began about February 25. By March 1, 

 20 chickens had died. The 120 survivors, of which 5 were sick, were inocu- 

 lated. The 5 recovered and the epizootic stopped. 



Barnyard 11. The epizootic began on February 4. From February 4 

 to 10, 10 chickens died. On February 10 the 48 living fowls were inoculated 

 in the wing with 0.5 cc. of the antigallinarum bacteriophage, as had been 

 all the chickens in the ten preceding experiments. The epizootic con- 

 tinued its course and 5 chickens died from February 10 to 17. On Feb- 

 ruary 17 the 43 fowls which remained were inoculated with 0.5 cc. of a mix- 

 ture of four strains of bacteriophage : active against B. gallinarum, B. pullo- 

 rum A, B. pullorum B, and B. pjaffi. The epizootic stopped immediately 

 after this second inoculation. 



Barnyard 12. This barnyard was adjacent to the preceding and here the 

 same facts were observed. A first inoculation made on February 9 on 80 

 chickens with a culture of the antigallinarum bacteriophage was without 



