x,B,4 Crowell: Pathologic Anatomy of Bubonice Plague 293 
in the polymorphonuclear leucocytes. In one of our cases no 
bacilli were found in smears, cultures, or sections of the spleen. 
As a rule, at autopsy smear preparations from the spleen show 
large numbers of plague bacilli, whereas in appropriately stained 
sections they frequently appear to be relatively few. 
Fibrin formation is not prominent in the spleen in bubonic 
plague. In a few cases only were fine threads of fibrin found 
in and about the vessels and sinuses. 
The essential lesions in the spleen in bubonic plague then 
are congestion and hzmorrhage, necrosis, endothelial prolif- 
eration, and bacillary infiltration, with degenerative changes in 
the walls of the blood vessels and trabecule. 
LIVER 
The liver regularly presents the condition of acute parenchy- 
matous degeneration, which does not essentially differ from the - 
same condition encountered in other acute infections. 
Hezemorrhages in the capsule of the liver and about the gall 
bladder are a frequent finding. Small hemorrhages and areas of 
focal necrosis are recognizable in some of the livers by the naked 
eye. Extreme congestion may be present in some cases, and 
some few present a fairly advanced fatty degeneration. In gen- 
eral, the macroscopic appearances of the liver are not especially 
characteristic of the disease and do not differ from those found 
in other acute infections. 
Infarcts and nodules similar to those found in the spleen were 
present in the livers of two of my cases (1969, 2993). An acute 
cholecystitis was also present in one instance (2074). 
HISTOPATHOLOGY OF THE LIVER 
The histological changes in the liver are chiefly acute paren- 
chymatous degeneration, congestion, and focal and larger areas 
of necrosis. Acute parenchymatous degeneration of a moderate 
grade is a practically constant finding in our cases. Congestion 
is also of frequent occurrence. This is especially marked in the 
central parts of the lobules, and the columns of liver cells may 
be widely separated by the engorged vessels, giving the ap- 
pearance of a chronic passive congestion. Pigment in the cells, 
such as is seen in such a condition, is, however, not frequently 
found. The liver cells show not only the evidences of acute 
parenchymatous degeneration, but are frequently vacuolated, and 
the nuclei often lie in a clear space. Foci are seen which seem 
to be especially in the peripheral parts of the lobules, in which 
the protoplasm has undergone solution, leaving a spongelike 
