STUDY OF PULMONARY GLANDERS. 
303 
grant leucocytes. The cellular roundness loses its smooth¬ 
ness, and all that remains is a mass of irregular granulations 
looking like nuclei undergoing segmentation, with some cel¬ 
lular elements in various degrees of degeneration. The bac¬ 
illi are more numerous, and may be detected in the whole 
extent of the diseased center. At the same time, the reac¬ 
ting layer of interstitial pneumonia spreads by the multipli¬ 
cation of the connective cells and x of the leucocytes, and the 
alveolar cavities, gradually obliterated, are no longer indi¬ 
cated except by star-like depressions. We may then recog¬ 
nize in the tubercle a degenerated center, granular and col¬ 
ored, formed of cellular remains ; a middle layer with fes¬ 
tooned outlines of fibrinous pneumonia, and an external layer 
of interstitial pneumonia. 
The presence of the center of degeneration is indicated 
on the surface of the lung by the appearance of a white, 
opaque spot in the middle of the gray granulation of the pre¬ 
ceding period. 
In the fourth stage, the zone of interstitial pneumonia ex¬ 
tends by degrees at the expense of the fibrinous disease. 
This, still indicated by some irregular spots enclosed in the 
neoformed tissue, soon disappears entirely. The interstitial 
pneumonia then constitutes by itself, around the central case¬ 
ous nucleus, a compact cellular wall in which two distinct 
layers can be found. One, the internal and larger, is formed 
of large yellowish cells, among which those of the giant kind 
are not uncommonly found ; the other, external and thinner, 
is formed of delicate connective fasciculi, separated by round 
cells with large nuclei of an embryonic nature. The internal 
layer may with propriety be called the “ epitheloid zone,’’ 
while the external is the incipient of the fibrous envelope. 
The degeneration of the center is complete. The bacilli exist 
on the periphery only, and are no longer visible in the cen¬ 
tral part. Only some granulous rods, scarcely colored, can 
be detected. A last stage is marked by the completion of 
the surrounding fibrous and epitheloid belts. 
There is then a caseous central focus, a middle zone, com¬ 
posed of epitheloid ceils and showing several narrow grooves, 
