_Vesicular bronchitis_, from its involving the smaller tubes and air cells, is much more frequently fatal than the tubular form of the disease, although in fatal cases the two forms will usually coexist. In a post-mortem examination of these cases, we find the bronchial membrane red and injected, pulpy and thickened. In a more advanced stage, the air cells and smaller tubes are filled with a viscid, puriform mucus, which prevents the air from reaching the vesicles during life, and the lungs from collapsing upon opening the chest after death. Minute ulcers are not uncommon upon the mucous membrane, the effect of these, being that of changing the character of the secretion from a transparent mucoid, to an opaque purulent form. Bronchial inflammation, as has been stated in another place, may result in emphysema of the lungs. In these cases, a valvular-like obstruction is produced in some of the bronchial tubes, which, offering little impediment to the entrance of the air, interferes with its escape, and thus by producing increased pressure upon the air cells supplied by the obstructed tube, a gradual dilatation or rupture ensues, resulting in the former case in vesicular, and in the latter, in interlobular emphysema. Disease of the heart may also result from chronic bronchial inflammation. Not only respiration, but the circulation may be so impeded as to exert a direct influence upon the heart. From the difficulty which the blood encounters in flowing through the branches of the pulmonary artery, the main trunk of that vessel becomes permanently dilated, while the right ventricle, from the increased force required to overcome the obstruction in the lungs, becomes gradually dilated, and at the same time, perhaps, hypertrophied. From the union of the two ventricles, the excessive action of the right may induce a similar action in the left, and thus in time result in that hypertrophy of both ventricles, which is sometimes found in persons who have suffered from chronic bronchitis. =Narrowing or Obliteration of Bronchial Tubes.= In some cases, in carefully tracing the bronchial tubes, we may find either a remarkable narrowness of the vessel, or a complete closure of the same. In the former cases, there is a distinct thickening of the walls of the tube, by an effusion of lymph, or blood and lymph, into the submucous tissues; or, from induration of the lung tissue around the smaller bronchial tubes, from tubercular or other deposits, a similar narrowing may result from external pressure. Complete closure may be found in any portion of the tubes, in the large trunks, arising from the main branches, as well as in the smaller branches. They may be detected by passing a blunt probe into the tubes. The branches will frequently be found continuing from the points of closure, as a fibrous cord. The most common seat of these closures is in the upper lobe of the lung, yet they have been found in the lower lobes.