210 STRONG, CROWELL, AND TEAGUE. 



Pleurse. — The parietal pleura covering the thoracic wall, dia- 

 phragm, and pericardium in many instances showed numerous 

 ecchymoses in the region of the infected lung, and very often 

 delicate, fibrinous adhesions were observed between the parietal 

 and visceral pleurse. In some instances many of the hsemor- 

 rhages were punctiform in character, but in others they were 

 confluent and formed diffuse, larger, dark-red patches. 



Lungs. — Numerous ecchymoses beneath the pleura were almost 

 always encountered, though they varied greatly in extent and in 

 number. The appearance of the lungs varied according to the 

 stage of the disease at the time of death. Generally the lungs 

 were dark red, voluminous, very rich in blood, and very oedem- 

 atous. From a careful study of the lesions of the lungs we can 

 conclude that plague pneumonia is an anatomically defined type 

 of disease different from other varieties of pneumonia. 



Fresh, fibrinous pleurisy was observed in every case, ex- 

 tending over the more marked areas of pneumonia. (See 

 Plates IX and X.) In some instances the delicate membrane 

 was reddish and slightly roughened; in other cases, grayish or 

 grayish white or yellowish, and could be easily peeled from the 

 surface of the lung. Rarely a gelatinous, oedematous exudate was 

 present. In two instances, the pleural cavity contained between 

 100 and 200 cubic centimeters of a serous haemorrhagic exudate 

 in which large numbers of plague bacilli were present. 



Some portion of the lung showed either inflammatory engorge- 

 ment or pneumonic infiltration. The seat of the pneumonia 

 varied greatly. The upper lobes appeared to be quite as fre- 

 quently involved as the lower. 



On section of the lung, the tissues adjacent to the areas 

 showing pneumonic involvement usually revealed very marked 

 congestion and oedema. Such areas were firmer than the normal 

 lung and tore more easily. On pressure, a reddish, serous fluid 

 exuded from the cut surface in great abundance. Sometimes in 

 these areas the oedema was so great as to give to the lung tissue 

 a jelly-like consistency. 



While in croupous pneumonia the first stage of inflammatory 

 engorgement as an independent condition is almost never, or 

 certainly very rarely, encountered, as the patient does not suc- 

 cumb within twenty-four to thirty-six hours from the origin of 

 the disease, in our cases of plague infection of the lung the early 

 stages of inflammatory engorgement were frequently met with 

 and often death occurred before the lesion had progressed fur- 

 ther, so that indeed in some instances no true pneumonia was yet 



