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remains localized in a gland or in a group of glands. However, 

 there does occur a final agonal dissemination of the organisms, 

 which does not differ in character from that of other micro- 

 organisms in other diseases. In a number of cases an extension of 

 the invasion by bacterial metastatic emboli does take place, but even 

 in these instances there is no evidence that the plague bacilli 

 multiply throughout the entire blood system, although we encounter 

 either more or less numerous metastatic emboli, generally in the 

 liver and the kidneys. 



THE INFECTION OF THE SPLEEN. 



However, one organ is perhaps infected in every case of plague — 

 the spleen. The pest bacillus, even in uncomplicated bubonic cases, 

 always gains access to its pulp spaces, and here it evidently finds 

 conditions favorable to its multiplication. 



In this respect plague may be likened to typhoid fever, in which 

 we also have a primary infection of the lymphatic tissue (Peyer's 

 patches) with an infection of the spleen which is never absent. 

 Another parallelism between typhoid fever and plague may be 

 found in a secondary infection of the lungs. Just as we find 

 secondary typhoid pneumonia dependent upon the presence of 

 enormous numbers of typhoid bacilli in the lungs, so we find 

 secondary plague pneumonia dependent upon the presence of 

 enormous numbers of plague bacilli in these organs. 



That cases of plague are usually not complicated by a general 

 septicgemic dissemination of the bacilli is also strongly indicated by 

 the result of blood examinations on living human beings. (For an 

 abstract of literature on this subject see Herzog and Hare: Does 

 Latent Plague Exist, etc.?) 



EXTENSION OF THE PRIMARY BUBO. 



After a gland has once become infected by plague organisms and 

 been invaded by enormous numbers of bacilli, it is usual for the 

 other lymphatics of the same chain to suffer likewise; the latter 

 then present the same gross and finer pathologic changes as the 

 former. For instances, it may happen that the first gland to be 

 invaded is a femoral one, from which the infection spreads from 

 gland to gland until it reaches the retroperitoneal lymphatics high 

 up in the abdomen. As in some of our cases, we may then find a 



