152 CLINICAL BACTERIOLOGY. 



genito -urinary tract ; to these may be added (5) the rare 

 cases in which the infection is of hematogenous origin ; and 

 (6) the still rarer, in which the peritonitis is the result of 

 operative intervention. In the first four groups named the 

 bacteria may migrate to the peritoneum (as in the case of 

 puerperal peritonitis, in which the exciting agents reach the 

 peritoneum from the uterus by way of the lymphatics) in 

 the absence of a breach in the continuity of the organ 

 primarily infected ; or there may be such a breach in con- 

 tinuity, and perforative peritonitis results. The latter is the 

 more dangerous variety, because with the microorganisms 

 other materials as, for instance, intestinal contents gain 

 entrance into the peritoneal cavity through the perfora- 

 tion, and these act as chemic and mechanical irritants, 

 and thus make possible and easy the proliferation of the 

 bacteria. By reason of the extraordinarily great absorp- 

 tive power and the extent of the absorbing surface of the 

 peritoneum, the entrance of bacteria into the peritoneal 

 cavity in experiments on animals does not invariably lead 

 to peritonitis, as has been demonstrated by the injection of 

 moderate amounts of pyogenic cocci into the abdominal 

 cavity of -dogs, rabbits, and guinea-pigs. For the develop- 

 ment of peritonitis a predisposing factor is additionally 

 necessary, such as especial virulence of the bacteria ^as, 

 for instance, in general septicemia the simultaneous en- 

 trance of intestinal contents, and, experimentally, the con- 

 joint introduction of considerable amounts of preformed 

 bacterial poisons, etc. 



The distinction between diffuse and circumscribed peri- 

 tonitis, which is so important clinically, is not supported by 

 bacteriologic examination, as the causative agents are the 

 same in both instances. 



The bacteriologic diagnosis can only be made in con- 

 nection with operation or on exploratory puncture. If it 

 is desired for special reasons in a given case to make an 

 examination for bacteria after death, this must be done as 

 soon as possible after dissolution has taken place, as the 

 result may be invalidated by the migration of bacteria from 

 the intestine after the lapse of a few hours. From the 

 effusion or from the deposits upon the peritoneum in ad- 

 dition to microscopic examination plates are simply cast 

 or tube-slants are smeared. 



The many bacteriologic investigations that have been 



