PATHOGENIC PROPERTIES OF CAUSATIVE AGENTS. 123 



pyogenes, which plays so important a role in the pathology 

 of the genito-urinary tract. 



THE PATHOGENIC PROPERTIES OF THE CAUSATIVE 



AGENTS OF INFLAMMATION WITH RELATION 



TO ANIMALS. 



The pathogenic activity of the exciting agents of inflam- 

 mation and suppuration with regard to animals is, on the 

 whole, much the same for all members of the group. In- 

 troduced subcutaneously, they cause local inflammation , 

 which manifests itself in simple swelling and slight febrile 

 movement. If the virulence of the bacteria be somewhat 

 greater, this inflammation leads to suppuration, and there 

 results a local abscess, which may rupture outward, and 

 undergo cure. Still greater virulence of the microor- 

 ganisms may cause the local imflammation and suppuration 

 to be complicated by sepsis that is, by intoxication with 

 bacterial poisons generated at the site of inflammation and 

 thence absorbed ; or it may lead to pyemia that is, to 

 dissemination of the bacteria through the lymph-channels 

 and the blood-vessels ; in the latter instance probably 

 through emboli containing bacteria and which give rise 

 to the formation of multiple purulent foci. 



The introduction of the causative agents of inflammation 

 into the serous cavities leads to the development of serous 

 or purulent pleuritis or peritonitis. Under all of these 

 conditions both the clinical course of the disease and the 

 postmortem findings exhibit completely the conditions 

 sufficiently well known from human pathology. 



Septicemia is exceedingly common in animal pathology, 

 while it occurs but seldom in human beings. This may be 

 considered as the expression of especially virulent activity 

 on the part of the causative factors of inflammation. It 

 occurs after intravenous introduction of the bacteria ; in 

 some cases, however, also in connection with every other 

 variety of inoculation and especially the infection of 

 rabbits with pneumococci. Characteristic of septicemia is 

 the absence of any localization of the disease. The clinical 

 picture has, therefore, no distinctive features. The animal 

 is severely ill, as may be recognized from the appearance 

 of the skin, of the eyes, and the general attitude. It does 

 not eat, and it often suffers from diarrhea, especially after 



