Virulence 447 



disappear, but which, after the lapse of several weeks or 

 months, again opens and forms a new abscess. 



In animals which are immune or nearly immune, like the 

 horse, the ass, the dog, and the rabbit, the subcutaneous 

 inoculation is followed by the formation of a small abscess 

 which speedily cicatrizes. 



Intraperitoneal inoculation in the guinea-pig gives rise to 

 lesions resembling tubercles. The omentum may be 

 extensively involved and full of softened nodes, and the 

 liver, spleen, and kidneys appear full of tubercles, but 

 careful examination will show that the tubercles occur only 

 upon the peritoneal surfaces, not in the organs. 



Intravenous introduction of the cultures produces a 

 condition much resembling general miliary tuberculosis. 

 All the organs contain the pseudo-tubercles in considerable 

 numbers. 



Virulence. Nocard found a culture still virulent after it 

 had been kept for four months in an incubating oven at 

 40 C. 



