THE RESPIRATORY TRAQT. 



723 



will ensue. If, on the contrary, the inflammatory tissue-like 

 new formation which fills the interior of the alveoli be entirely 

 deprived of its nutrient alveolar blood-vessels, a tubercle will be 

 the result, corresponding in size with the avascular lobular dis- 

 trict. This is the most common termination of catarrhal pneu- 

 monia, and is almost inevitable in persons of a poor constitution. 

 (See Fig. 323.) 



So long as the inflammatory corpuscles remain interconnected 

 by delicate filaments i. e., remain a tissue small districts, not- 

 withstanding the lack of blood-vessels, may become supplied with 

 basis-substance similar to that of cartilage, the so-called horny 



c I 



UF 



FIG. 323.- 



CATARRHAL PNEUMONIA OF A CHILD, CHANGING 

 TO TUBERCULOSIS. 



/'/; unchanged wall of alveolus; IF, wall of alveolus crowded with inflammatory cor- 

 puscles; C, alveolus filled with coagulated albumen, inflammatory corpuscles, and.*?, detached 

 alveolar epithelia ; D, cluster of inflammatory corpuscles, in- commencing shrinkage. Mag- 

 nified 500 diameters. 



metamorphosis or obsolescence of the tubercle. As soon, on the 

 contrary, as the connection of the inflammatory corpuscles is 

 broken, and the inflammatory new formation ceases to be a 

 tissue, the corpuscles will shrivel, in part become disintegrated 

 in short, undergo the "cheesy" metamorphosis. In the sur- 

 rounding lung- tissue, which is still provided with blood-vessels, 

 a new formation may ensue, resulting in the production of a 





