x,B,4 Crowell: Pathologic Anatomy of Bubonic Plague 299 
Near the tips of the papille or villi in the areolar tissue between 
the glands in both the stomach and intestine small hemorrhages 
occur from the capillaries. These hemorrhages may involve only 
the area between two glands or may include several papille. The 
vessels in the lower stratum of the mucosa and submucosa show 
engorgement. In simple hemorrhages no other change is seen. 
In those areas in the stomach that have been referred to as 
hemorrhagic erosions there is seen a severer change. Here the 
hemorrhage involves a larger area and extends more deeply into 
the mucosa. However, this lesion is usually entirely restricted 
to the mucosa, only one of our preparations showing hemorrhage 
below this, and there is always a zone of hemorrhagic glandular 
tissue recognizable above the muscularis mucosze. Necrosis and 
sloughing of a cup-shaped area of the mucosa occurs, and the 
margins of the small ulcer are formed by mucosa which appears 
normal with the exception that hemorrhage has occurred into - 
it. A large number of polymorphonuclear leucocytes has been 
noted in the hemorrhagic tissue. Necrosis of the cells of the 
upper layer of the mucosa of the stomach and intestine has been 
stated by many authors to be very common in plague. In my 
work the changes in these cells have been interpreted as a 
simple post-mortem digestion. 
Pest bacilli are demonstrable in the hemorrhagic areas, but 
I have never encountered them in very large numbers. Al- 
though these hemorrhages have been interpreted by many, with 
whom I do not disagree, as due to bacillary emboli, we have failed 
to demonstrate such emboli in our sections. In the cases cited 
above as showing abscesses of the intestinal mucosa, the lesions 
show sharply circumscribed areas of necrosis in the mucosa and 
submucosa, with the presence of polymorphonuclear leucocytes, 
and engorgement of the vessels in the neighborhood. Numerous 
bacilli are seen in the necrotic areas. 
Many authors on the subject of plague refer to the occurrence 
of swelling and hyperemia of the intestinal lymphoid tissue, 
which may be readily visible to the naked eye. No such case 
has been seen in my series, although microscopic sections from 
the intestines which pass through the follicles often show marked 
engorgement of these structures. 
PERITONEUM 
The most frequent change found in the peritoneum is the 
presence of hemorrhages. They occur either in the peritoneum 
itself or in the subperitoneal tissues. They are most abundant 
in those cases of femoral buboes which have marked primary 
