MORBID ANATOMY I 65 



The lesions consist of nodules varying in size from that of a 

 millet seed to that of a walnut. This condition is, as a rule, 

 accompanied by a chronic pleurisy with extensive adhesions 

 and also effusions into the plural cavities. 



In the liver the lesions consist largely of nodules com- 

 posed like those in the lymphatic glands, of a firm white 

 fibrous sac containing a greenish-yellow, cheesy mass of vary- 

 ing consistenc}'. Cases have been reported, however, where 

 the entire organ was filled with miliary nodules. 



The kidneys are rarely affected but when they are the 

 lesions assume the same characteristic appearance of a firm 

 walled abscess protruding on the surface of the organ. As a 

 rule, only one or two such foci are observed in each case. 



A histological examination of tissue containing miliary or 

 sub-miliary nodules, show them to be composed chiefly of 

 leucocytes and nucleated round cells, the greater part of which 

 are irregular in shape, especially toward the center where 

 many of them are transformed into a granular detritus. Among 

 the cells singly or arranged in clumps, are seen the short 

 plump bacteria which stain irregularl}-. The shape varies 

 considerably from oval or oblong to dumb-bell and club shape. 



The bacteria are frequently seen within the degenerated 

 leucocytes, the destruction of which is due, according to 

 Preisz, to the specific chemical products elaborated by these 

 microorganisms. 



The microscopic appearance is somewhat similar in all the 

 lesions whether located in the lymph glands, lungs, liver, kid- 

 neys or spleen. In the lungs the histological picture re- 

 sembles that of broncho-pneumonia. In the liver the lesions 

 originate in the portal capillaries, where the bacteria cause a 

 proliferation of the endothelial cells, which, together with the 

 accumulation of leucocytes and red blood corpuscles, cause the 

 obliteration of the vessels. In no case have giant cells been 

 observed. The surrounding hepatic cells become swollen, 

 then granular and finally the}' undergo atrophy, leaving open 

 spaces between them. Numerous round cells appear in the 

 periphery of the nodules which gradually undergo a connective 



