UBIQUITY OF BACTERIOPHAGE 427 



No. 22. The same animal as No. 20 (above) but tested eight days 

 later. 



No. 23. A carriage horse at Saigon. 



No. 24. A carriage horse at Saigon. 



No. 25. A saddle-horse at Nha-Trang (Annam), 



No. 26. A saddle-horse at Phantiet (Annam). 



There is no point in adding to this list; the thirty-six other specimens 

 gave entirely comparable results. 



Incidentally, horses No. 19 and No. 20 were examined to see if the 

 bacteriophage presented a virulence for various other bacteria, including 

 the following organisms : 



1. A cocco-bacillus (?) isolated from the nasal mucus of a horse, in the 

 same stable, which showed the evening before an elevation of 

 temperature: 



Horse No. 19 ( + +), horse No. 20 (+ + ). 



2. A cocco-bacillus isolated by Cesari from the blood of a horse 

 slaughtered in the abattoir of Vaugirard: 



Horse No. 19 (+), horse No. 20 (++). 



3. Salmonella (hog cholera): 



Horse No. 19 (++), horse No. 20 (+ + ). 



4. B. enteritidis: Horse No. 19 (0), horse No. 20 (-{-). 



These results show that at a single time the bacteriophage may show 

 a virulence for a large number of bacteria. It is significant that only in 

 horses Nos. 16, 17, and 18, which lived in an environment contaminated 

 by B. gallinarium, did the intestinal bacteriophage show a definite 

 virulence for this bacterium. 



Examination was made of twenty-three specimens of serum, of clot 

 remaining after the decantation of the serum, and of the leucocytic layer 

 on top of this clot, taken from horses harboring in their intestines a 

 bacteriophage active for B. dysenteriae. In no case was a bacteriophage 

 found. In all instances the specimens of blood were collected about 

 two weeks after the last injection of toxin or of bacilli. All the speci- 

 mens of blood examined came from horses furnishing anti-dysentery 

 serum. It was therefore not determined whether the bacteriophage may 

 not pass into the circulation immediately after the injection, especially 

 when living bacteria are used. As a matter of fact the passage of the 

 intestinal bacteriophage into the circulation has been observed in the 

 rat, and in the fowl in cases of septicemia. In all cases the demonstration 

 of the presence, it might be said constant presence, in the excreta of the 

 horse of a bacteriophage active for the Shiga bacillus, and the absence 



