94 ORIENTAL PLAGUE chap. 



shape to B. pestis. Cultures and animal experiments 

 confirmed this diagnosis. The spleen and liver were 

 enlarged, dark, and firm ; when cut into, the organs were 

 not found juicy. Film specimens of these organs yielded 

 abundance of plague bacilli ; they invariably and readily 

 showed the bipolar staining. Inoculation of these 

 samples and of cultures from them on guinea-pigs and on 

 rats confirmed the diagnosis of B. pestis. The small 

 intestine of these experimental animals was congested, 

 relaxed, and contained more or less blood-stained mucus. 

 Film specimens of this mucus showed, amongst many 

 other microbes, fairly numerous oval bacilli showing 

 readily the bipolar staining. The lungs showed general 

 congestion ; in the pleural cavity there was a small 

 amount of sanguineous exudation. Film specimens of 

 the lung juice, as also of the pleural exudation, exhibited 

 numerous plague-like bacilli. Examined under a glass, 

 small hemorrhagic spots on the surface of the lung were 

 readily recognisable. Film specimens of the heart blood 

 showed fairly numerous bacilli which, in size and aspect 

 and staining power, corresponded to B. pestis. Cultures 

 left no doubt as to the real character of these blood 

 bacilli ; in all respects they were true B. pestis. So also 

 cultures made of the intestinal mucus and lung juice. 



There is, then, ample evidence that these rats died of 

 Oriental plague, and that they exhibited the characters of 

 a general infection ; that is to say, they suffered the 

 hemorrhagic type of plague with the habitual general 

 distribution throughout the body of the plague bacilli. 

 These results are in perfect accord with those observed in 

 other countries — India, Sydney, and Cape Town. 



The Bristol rat bacillus differed, however, from that of 



