BACTERIUM DIPHTHERIA 471 



probably responsible for suppurations occurring under 

 certain special conditions. With these facts in mind speci- 

 mens of pus were derived from thirty cases with suppurating 

 wounds in the University of Pennsylvania Hospital, and 

 careful bacteriological examination of these specimens 

 showed the presence of bacterium pseudodiphtheriticum in 

 43 per cent, of the cases. These organisms were always 

 found in conjunction with one or more of the group of pyo- 

 genic organisms, and it is impossible to state how much 

 of the effect was due to any one of the organisms present. 

 It seems probable, however, in the light of what has been 

 said, that these bacteria were present not merely as acci- 

 dental invaders, but that in some way they contributed 

 toward the results. 



The fact that some of the organisms isolated from the 

 pus, when inoculated into the peritoneal cavity of guinea- 

 pigs, show distinct pyogenic properties gives strong sup- 

 port to the opinion that this group is of greater importance 

 than was heretofore supposed. Repeated passage through 

 guinea-pigs serves to so increase the pathogenic properties 

 of these organisms that they cause the death of the animal 

 in less than twenty-four hours with marked inflammatory 

 reaction affecting the peritoneum as well as the abdominal 

 organs. 



The morphologic and biologic characters of some members 

 of the group of bacterium pseudodiphtheriticum are sug- 

 gestive of those of bacterium diphtherise. Other members 

 of the group, however, are readily differentiated from bac- 

 terium diphtherise by either the morphologic or the biologic 

 characters, or by both. Many of the members of the group 

 produce very little acid when grown in carbohydrate media, 

 and the slight degree of acidity produced is frequently 



