152 ORIENTAL PLAGUE chap. 



(a) A rat was inoculated on April 26 with virulent agar 

 culture of B. pestis. The animal was dead on 29th of the 

 month with acute typical plague. The bladder was found 

 distended by blood -tinged urine. With this urine one 

 rat and one guinea-pig were injected subcutaneously ; 

 both animals died of plague with copious presence of 

 B. pestis in the bubo and spleen, (b) A guinea - pig 

 was injected subcutaneously with recent agar culture 

 of B. pestis on February 18. It was dead on the 22nd 

 of the month with typical plague. The bladder was 

 distended with urine. A guinea-pig was injected sub- 

 cutaneously with this urine on the same day. The animal 

 was found dead with typical subacute plague on March 1, 

 the bubo, spleen, liver, and lungs containing in the 

 necrotic nodules crowds of B. pestis. Blood must there- 

 fore have found its way into the cavity of the bladder in 

 these cases and with it presumably B. pestis. Hence the 

 urine of a rat affected with the acute virulent (septi- 

 csemic) type of plague has to be regarded as very possibly 

 infective. 



The lung of the plague rat is always more or less 

 congested, occasionally showing minute capillary hsemor- 

 rhages. Sections show in some lobules effusion of blood, 

 .and in films thereof B. pestis is detected. But I have 

 not been able to satisfy myself that the mucus of the 

 mouth, pharynx, or larynx of the rat dead of acute plague 

 commonly contains B. pestis ; several experiments made 

 in this direction have not been productive of positive 

 results, the mucus having been taken carefully without 

 injuring the blood-vessels of the mucous membranes. J 



The lung appearances are, however, altogether different 

 in rats which do not succumb with acute plague, but 



