270 BACTERIOLOGY. 



the results are also fatal, and at autopsy a genuine 

 fibrinous peritonitis is found. There is usually an ac- 

 cumulation of serum in both the peritoneal and pleural 

 cavities. At autopsies after both methods of inocula- 

 tion the organisms will be found in the blood and inter- 

 nal viscera in pure cultures. 



When animals are inoculated with small doses (less 

 than 1 c.c. of a bouillon culture) of this organism 

 death may not ensue, and only a local inflammatory 

 reaction (abscess-formation) may be set up. In these 

 cases the animals are usually protected against subse- 

 quent inoculation with doses that would otherwise 

 prove fatal. 



Most interesting in connection with bacillus pyocy- 

 aneus is the fact, as brought out in the experiments of 

 Bouchard, and of Charrin and others, that its products 

 possess the power of counteracting the pathogenic ac- 

 tivities of bacillus anthracis. That is to say, if an 

 animal be inoculated with a virulent anthrax culture, 

 and soon after be inoculated with a culture of bacillus 

 pyocyaneus, the fatal effects of the former inoculation 

 may be prevented. 



In the literature upon the green-producing organisms 

 that have been found in inflammatory conditions sev- 

 eral varieties believed to be distinct species have 

 been described, but when cultivated side by side their 

 biological differences are seen to be so slight as to ren- 

 der it probable that they are but modifications of one 

 and the same species. 



THE BACILLUS OF BUBONIC PLAGUE. 



Before passing from the subject of suppuration it 

 may not be inappropriate to call attention to the light 



