IOO MEDICAL BACTERIOLOGY 



The avian type develops best at temperatures too high for the cultivation of 

 the other types. 



The bovine type is more virulent for guinea-pigs and rabbits than the human. 

 It kills rabbits in 4 to 6 .weeks, while the human type requires several months or 

 more to kill rabbits and frequently fails, too. The avian type is only slightly 

 pathogenic for guinea-pigs, and is virulent for rabbits. The ichthic grows best 

 at room temperature and is not pathogenic for Laboratory animals. 



