310 BACTERIOLOGY. 



and soon after be inoculated with a culture of bacillus 

 pyocyaneus, the fatal effects of the former inoculation 

 may be prevented. Emmerich and Low * are inclined 

 to attribute this to the direct bacteriolytic action of the 

 pyocyaneus enzymes upon the anthrax bacilli introduced 

 into the tissues. 



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 BACILLTTS OP BUBONIC PLAGUE (BACILLUS PESTIS). 



Before passing from the subject of suppuration it 

 may not be inappropriate to call attention to the light 

 that modern methods of investigation have shed upon 

 the etiology of bubonic plague, an epidemic disease 

 characterized by suppuration of the lymphatic glands, 

 and accompanied by a very high rate of mortality. 



This pestilence, probably endemic in certain sections 

 of the Orient, is one of the most conspicuous epidemic 

 diseases of history. Since early in the Christian era epi- 

 demics and pandemics of plague have made their appear- 

 ance in Europe at different times. During and for a time 

 after the Middle Ages it was more or less frequent in 

 India, China, Arabia, Northern Africa, Italy, France, 

 Germany, and Great Britain. In history it is variously 

 known as the " Justinian Plague " of the sixth century, 

 the " Black Death " of the fourteenth century, and the 



1 Miinchener mod. Wochenschrift, 1898, No. 40 ; Centralblatt fiir 

 Bakteriologie unci Parasitenkunde, 1899, Abt. i. No. 1, p. 33. 



