MORBID ANATOMY 449 



or opaque and which contains flakey or lumpy masses. Simi- 

 lar fibrinous masses often lie on the outer surface of the peri- 

 cardium. 



After the disease has existed for some time, the affected 

 parts of the lungs undergo induration, cicatrization, caseation, 

 calcification, necrosis or suppuration. At first the interstitial 

 infiltration becomes dense, solid and dry and changes into 

 firm connective tissue which makes a crunching noise while 

 it is being cut with the knife. In other places we have fatty 

 degeneration, caseation, calcification or suppuration, in which 

 the enclosed lobules of the lungs, in consequence of the exist- 

 ing suppuration, become gangrenous, and form sequestra sur- 

 rounded by sequestral cavities which have smooth walls. The 

 dead portions of the lungs may remain unchanged in these 

 cavities for a long time. Frequently they become softened to 

 the consistency of a greasy, yeast like paste. Sometimes, when 

 they are comparatively small, they become absorbed, and a 

 scar is formed. The hepatized lobules of the lungs rarely re- 

 gain their normal condition after the absorption of the exudate. 

 More frequently they atrophy or collapse, undergo atelectasis, 

 calcification or softening, become necrotic or suppurating or 

 form cavities. On the pleurae we find thick and wart-like 

 hypertrophies of connective tissue, which frequently cause 

 the lungs to adhere to the sides of the chest. 



The changes in the lungs and pleurae are the most im- 

 portant general changes in cases of pleuro-pneumonia. It is 

 stated that we may sometimes meet with an interstitial fibrin- 

 ous exudate in the liver with atrophy of the liver cells ; sero- 

 fibrinous effusions into the articulations, tendon sheaths, sub- 

 cutis, dewlap and brisket ; intestinal catarrh ; areolation of 

 Peyer's patches and ulcers on the gastro-intestinal mucous 

 membrane. 



The views of pathologists differ as to the nature of the 

 earliest changes in contagious pleuro-pneumonia and it is not 

 within the scope of this work to present imperfectly developed 

 or controverted theories. Without entering into a discussion of 

 the various views, it is clear that there is an inflammatory 



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