362 



THE BACTERIOPHAGE AND ITS BEHAVIOR 



After the death of the injected animal, they withdrew aseptically a 

 few drops of heart blood and seeded it immediately in serum-bouillon. 

 The culture so obtained was tested against their strangles antiserum 

 for its antigenic value. Table 42 summarizes their experiments, the 

 figures indicating the results in units of antibody. There can be no 

 question from these results but that the streptococcus acquires a new 

 individuahty within the body of each of the different animals. 



The authors of these experiments conclude that the number of pas- 

 sages is a function of the resistance of the animal to infection; the 

 longer death is delayed, they say, the more quickly the streptococcus 



STRAINS OF THE STRANGLES STREPTOCOCCUS 



D61ici- 

 euse 



BH542 Carpano 



Passages through mice 



First passage . . 

 Second passage . 

 Third passage . . 

 Fourth passage . 

 Fifth passage . . 



500 



75 



10 







Passages through rats 



First passage . . 

 Second passage , 

 Third passage . , 

 Fourth passage 

 Fifth passage . . 

 Sixth passage . . 



150 



50 



5 







