RABBITS. 



In seven experiments, collodium sac cultures were allowed 

 to remain in the abdominal cavities of guinea pigs for five days 

 and in four experiments they were kept in that position for 

 seven days. Tn attempts to increase their virulence by passage 

 through rabbits, each of the eleven strains were retained in their 

 bodies for seven days. An examination of hanging-drops made 

 from the collodium sac cultures after removal from the abdom- 

 inal cavities of the animals showed an abundant growth of the 

 germs. The virulence of the germs was tested by inoculation 

 into the ears of the rabbits. 



The results of these experiments were negative in all cases. 

 Contrary to this result Heinemann 9 has succeeded in raising the 

 virulence of a number of strains of streptococcus lacticus by 

 successive passage through rabbits to an equality with that of 

 the streptococcus pyogenes. 



The fact that their retention for a period of seven days in 

 the bodies of both guinea pigs and rabbits without increasing 

 their virulence would indicate that they are not easily endowed 

 with pathogenicity and that their introduction into the digestive 

 tract in milk would be harmful only by the chemical changes 

 which they might effect in the contents of the intestines. 



