302 
E. LECLAINCHE AND L. MONTANE. 
are surrounded by a ring of round cells. The sub-pleural con¬ 
nective tissue and that of the interlobular trabeculas are cede- 
matous, and are infiltrated with migrating cells, both isolated 
and gathered in masses. In the whole extent of the involved 
tissue, the glanders bacilli are found free between the cells, 
and regularly disseminated throughout. 
The development of the superficial tubercle always occurs 
in the neighborhood of the pleura, or of an interlobular band, 
often taking place at the point of union of the pleura with a 
band, or again at the junction of the two bands. The result 
of this is that the tubercle seems under-stretched, and par¬ 
tially limited by a band of inflamed cellular tissue. 
The inflammatory center includes a group of alveoli, 
filled with finely granular fibrine, the remains of a primitive 
hemorrhage, enclosing some mononuclear leucocytes. The 
alveolar walls are thickened, and contain leucocytes and some 
free bacilli, the latter principally in the neighborhood of the 
connective band. This incipient tubercle is identified by a 
rounded ecchymotic spot under the pleura. 
In the second period, the central portion of the primitive 
focus of pneumonia is overrun by an active immigration of 
leucocytes, which infiltrate the walls and fill the alveoli, ap¬ 
pearing under section as a strongly colored bunch of grapes. 
Bacilli, not yet very numerous, are seen in the alveolar walls 
and in the cavities o L the vesicles. All around the central 
focus of leucocytic apoplexy there exists a zone of fibrinous 
pneumonia which does not undergo noticeable transforma¬ 
tions. The contents of the alveoli have, however, become 
more granulated, and are colored of a slight rosy tint, with 
the picro-carmine. By contrast, the surrounding pulmonary 
tissue undergoes marked modifications of reaction ; this zone 
is indicated by the evolution of a rfiore or less extensive epi¬ 
thelial pneumonia. The epithelium of the vesicles now drop 
off and proliferates, filling up the alveolar cavities, and at this 
stage the tubercle is seen under the aspect of a grayish, semi¬ 
transparent granulation. 
The central focus rapidly undergoes the caseous degener¬ 
ation, involving at one time the alveolar walls and the immi- 
