x,B,4 Crowell: Pathologic Anatomy of Bubonic Plague 2387 
yellowish gray, and the areas are surrounded by a narrow red 
hyperemic zone. The consistence of the nodules is firm in the 
earlier lesions, and softening occurs in the central part of the 
older nodules. In the same lung there may be nodules of vary- 
ing size, color, and consistence. In some cases it is possible to 
recognize a definite arrangement of these about the bronchi, 
while in other cases no such arrangement is discernible. The 
nodules are circular in outline and discrete, and no evidence of 
any attempt at fusion of the nodules to form a more general 
lobar involvement has been seen. The sharp delimitation of 
these areas contrasts with the indefinite outline of the early 
pulmonary lesions in primary pneumonic plague. The lung 
substance between these nodules is crepitant, but as a rule con- 
gested and cedematous. 
It will thus be seen that the lesions in this type of plague 
correspond to those described in other infections as metastatic - 
or septic embolic pneumonia. However, these lesions never pro- 
gress to the stage of cavity formation, probably because of the 
short duration of the disease. These nodules can best be ex- 
plained on the basis of a metastatic or embolic origin. While 
the type of true peripheral infarct and the metastatic embolic 
type of pneumonia are similar from the etiologic and microscopic 
standpoints, it seems desirable to separate them on account of 
their macroscopic variations. The term “infarct” suggests at 
once the idea of a peripherally situated, cone-shaped area of 
necrosis with possible suppuration, such as is encountered in my 
second class. When, on the other hand, cases occur with globular 
nodules found widespread throughout the lung, having no pre- 
dilection for a peripheral situation, the cases may well be segre- 
gated in a class by themselves. From their situation in relation 
to the bronchi, and from the existence of a true bronchitis in 
these cases, it may well be that some of them are of bronchogenic 
rather than hematogenic origin. 
An attempt has been made to correlate these pulmonary lesions 
with the existence of laryngeal, pharyngeal, or tonsillar lesions, 
but all three types occur irrespectively of whether such lesions 
exist and independently of the site of the primary bubo. My 
series shows that 5 of the 13 cases with pulmonary lesions had 
neither cervical buboes nor pharyngeal lesions; that of 10 cases 
of cervical buboes 6 had pulmonary lesions; and that of 11 
cases of pharyngeal lesions 7 had pulmonary lesions. These 
figures do not give proportions sufficient to justify one in drawing 
any positive conclusions as to the necessity for a causal relation 
between these lesions. This doubt as to the causal relation is 
