ANATOMICAL CHANGES 



493 



lymphoid tissue. At a later period, when disorganisation of 

 the gland has occurred, they become irregularly mixed with the 

 cellular elements. Later still they gradually disappear, and 

 when necrosis is well advanced it may be impossible to find any 

 a point of importance in connection with diagnosis. In the 

 spleen they may be very numerous or they may be'' scanty, 

 according to the amount of blood infection which has occurred ; 





FIG. 149. Section of a human lymphatic gland in plague, showing 

 the injection of the lymph paths and sinuses with masses of plague 

 bacilli seen as black areas. 



Stained with carbol-thionin-blue. x 50. 



iii the secondary lesions mentioned they are often abundant. 

 In the pulmonary form the lesion is the well-recognised " plague 

 pneumonia." This is of broncho-pneumonic type, though large 

 areas may be formed by confluence of the consolidated patches, 

 and the inflammatory process is usually attended by much 

 haemorrhage ; the bronchial glands show inflammatory swelling. 

 Clinically there is usually a fairly abundant frothy sputum often 

 tinted with blood, and in it the bacilli may be found in large 



