PLATE VII. A TUBERCLE IN THE LUNG HEALED 



In this photograph of a highly magnified tubercle, 

 which has healed by the formation of scar-like tissue 

 about it, one sees the minute air chambers of the lung 

 surrounding the solid tubercle. At the site of the tuber- 

 cle the air chambers, and hence the usefulness of this 

 portion of the lung, have been destroyed. 



