x,B,4 Crowell: Pathologic Anatomy of Bubonic Plague 289 
of fibrin on the pleura, and this contains a few leucocytes and 
some bacteria. The endothelial cells beneath the fibrin are 
seldom recognizable. Just beneath the pleura at these points 
there is usually a very dense mass of bacilli. 
Surrounding the nodules just described there is seen a zone of 
compressed alveoli with engorged vessels. 
Sections of the bronchioles and bronchi show regularly some 
desquamation of the lining epithelial cells and a mass of cell 
detritus containing leucocytes and bacteria in the lumen. In 
the walls of the bronchi there is marked engorgement of the 
vessels. 
PLEURA 
The most frequent lesion of the pleura is the presence of 
punctate hemorrhages, which may be very few in number or may 
be numerous and scattered over both the parietal and the visceral 
layers. Such hemorrhages were noted in 33 of our cases, these ~ 
standing, in this series, next in frequency only to those on the 
epicardium. Localized areas of an acute fibrinous pleuritis may 
also be present over the peripherally placed infarcts and metas- 
tatic foci in the lungs. 
BRONCHI AND TRACHEA 
Congestion and an acute inflammation may be present in the 
trachea and bronchi, occurring most often in those cases in which 
there was specific pulmonary involvement. The inflammation 
may be of the simple catarrhal or of the croupous type. One case 
occurred in which a large plug of fibrin and mucus was pulled out 
of the trachea and bronchi, of which it formed an imperfect cast. 
LARYNX 
The larynx is most liable to involvement in the case of axillary 
or cervical buboes in which there is a widespread involvement 
of the pharyngeal region. Hzmorrhages on both sides of the 
epiglottis, and cedema, which may involve the aryteno-epiglottid- 
ean folds, the epiglottis, and the vocal cords, constitute the 
chief laryngeal changes encountered. A pseudomembranous 
laryngitis and pharyngitis was found in two cases (2389, 3129), 
in one of which (3129) the clinical diagnosis of diphtheria had 
been considered. 
SPLEEN 
The spleen in bubonic plague presents a very characteristic 
appearance, the most characteristic features being its color and 
its consistence. The spleen is usually enlarged, but not in all 
cases. The size varies from those which are smaller than normal 
