722 THE RESPIRATORY TRACT. 



tissue, with profuse pigmentation of the newly formed tissue, the 

 pigmentation being probably caused by an incomplete develop- 

 ment of red blood-corpuscles or haematoblasts. 



HypostaMc pneumonia is the consolidation of the pendent portions of the 

 lung toward the end of life. It consists in an engorgement of all the blood- 

 vessels, a sero-alburainous exudation, and a profuse detachment of the alveolar 

 epithelia. The latter and a varying amount of red blood-corpuscles and 

 exudation corpuscles, which in all probability are emigrated colorless blood- 

 corpuscles, compose the plug choking the alveoli. The interstitial tissue 

 takes no active part in the process. 



(~b) Catarrhal pneumonia. The most characteristic feature of 

 this form is the inflammatory new formation in the interstitial 



FIG. 322. CHEESY PNEUMONIA, OR CHRONIC TUBERCULOSIS 

 OF THE LUNG. 



E, elastic frame of the former alveolar walls ; 8, shriveled inflammatory corpuscles and 

 granular detritus ; M, so-called margaric acid crystals. Magnified 500 diameters. 



connective tissue. The alveoli are filled with an albuminous 

 exudate, holding inflammatory corpuscles, produced in part by 

 the proliferation of the connective tissue, in part by an endo- 

 genous new formation in the alveolar epithelia to some extent 

 they may also be due to an emigration of colorless blood-corpuscles, 

 which occurrence is possible so long as the blood-vessels are not 

 destroyed. With a new formation of the lost blood-vessels cure 



