272 PATHOGENIC BACTERIA. 



organism is injected subcutaneously into a guinea-pig, a 

 voluminous abscess results. Not long afterward the lym- 

 phatic vessels and glands of the region are the seat of swell- 

 ing and induration, and extensive phlegmons form, which 

 rupture externally and discharge considerable pus. The 

 animal, of course, becomes extremely ill and seems about 

 to die ; instead, it slowly recovers its normal condition. 



In other animals, as the cow and the sheep, the subcu- 

 taneous inoculation results in an abscess relatively less 

 extensive. This ulcerates, then indurates, and seems to 

 disappear, but after the lapse of several weeks or months 

 opens again in the form of a new abscess. 



In animals which are immune or nearly immune, like 

 the horse, the ass, the dog, and the rabbit, the subcuta- 

 neous inoculation is followed by the formation of a small 

 abscess which speedily cicatrizes. 



Intraperitoneal inoculation in the guinea-pig gives rise 

 to an appearance resembling tuberculosis. The omentum 

 may be extensively involved and full of softened nodes. 

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

 but careful examination will satisfy the observer that 

 the tubercles are 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 consider- 

 able numbers. 



