492 



PLAGUE 



Clinically there is usually a fairly abundant frothy sputum often 

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

 numbers. Sometimes, however, cough and expectoration may 

 be absent. The disease in this form is said to be invariably 

 fatal; it is also extremely infective. In the septicemic form 

 proper there is no primary bubo discoverable, though there is 

 almost always slight general enlargement of lymphatic glands; 



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. 



here also the disease is of specially grave character. A bubonic 

 case may, however, terminate with septicaemia ; in fact, all 

 intermediate forms occur. An intestinal form with widespread 

 affection of the mesenteric glands has been described, but it is 

 exceedingly rare — so much so that many observers with extensive 

 experience have doubted its occurrence. In the various forms 

 of the disease the bacilli occur also in the blood, in which they 

 may be found during life by microscopic examination, chiefly, 



