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demarcating inflammation, by energetic capsulation from apparently 

 healthy or freshly hepatised tissue. 



It is a peculiarity of the virus of pleuro-pneumonia and its toxines 

 to facilitate the closure of all nutrative channels by the thrombosing of 

 the blood vessels and the progressive-productive processes of the inter- 

 stitia, thus forcing necrosis to take place. Even if in certain portions, 

 through resolutio, a restitutio ad integrum takes place, bands of connective 

 tissue remain behind along the septa and bronchi. A sequester appears 

 as a brownish -grey mass surrounded by a granular slippery capsule, from 

 which portions of blood vessels and thick fragments of bronchi project. 

 Mummification of sequesters often takes place, and if bacteria from out- 

 side penetrate, fermentation processes can take place, and deliquation 

 often causes the whole to anneal. 



Sussdorf observed such cicatrisation of small foci in protracted cases 

 of lung-sickness. Two such cases are in our collection. The sequester 

 is always intimately connected with the thickened septa. This stage of 

 pleuro-pneumonia corresponds to a Pneumonia dissecans. 



The bronchi are always more or less affected, the peribronchial tissues 

 are during the initial stages oedematous ; later on changes take place in 

 their lymph vessels, with exudation of fibrine, followed the formation by 

 neoplastic connective tissue. For this reason the bronchi appear in 

 chronic cases as thick, rigid tubes, sometimes containing plugs of fibrine, 

 close beside them one usually finds blood vessels containing a thrombus, 

 whose walls present the same thickened appearance. I have not yet seen 

 any direct bronchioectasia as described by Sussdorf. 



The mucous membranes of the largest bronchi are usually somewhat 

 swollen, with small superficial haemorrhages. The nearer they are to 

 the diseased lobuli, the more readily are they drawn into the morbid 

 process ; they then contain slimy, crumbly, friable plugs. 



Besides all these manifestations of exudative pneumonia, closer 

 attention must be given to the interstitium of the interlobular, inter- 

 alveolar, and of the peribronchial tissue. 



Pleuro-pneumonia virus reaches the lungs by inhalation, as has been 

 demonstrated by experiment ; arrived there, its pathogenic influence is 

 first felt by the lymph vessels. Without going into the question 

 whether the processes take their origin in the lymph vessels of the inter- 

 stities or of the pleura, it is certain that its dissemination is closely con- 

 nected with their course. In the beginning of the disease, one finds the 

 interstities broadened, waxy, yellowish-white, greatly infiltrated, covered 

 with a reticulation of haemorrhages. 



The margin of such parts are white, consolidated, but the interior is 

 filled with small cavities and crevices, containing a clear, amber-coloured 

 fluid or fibrinous coagulum. In later stages, which can often be found 

 on the same section, the walls of the cavities or varices, which are nothing 



