196 DISEASES OF THE PARENCHYMA OF THE LUNG. 



of induration, so that a large portion of the posterior part of the lung 

 exhibits a brownish-red, compact, but friable infiltration, out of which 

 only small quantities of purulent but adhesive liquid can be expressed. 

 If the disease be of still longer standing, we find that the color of the 

 dark -brown infiltration has gradually faded from the centre toward the 

 periphery, so that the middle assumes a grayish appearance, its firm- 

 ness being at the same time materially diminished. Upon microscopic 

 examination, we perceive a further advance in the fatty degeneration 

 of the cellular elements, and a large admixture of granular multinuclear 

 cells (pus-cells). The alterations which we have just described are 

 analogous to those of red hepatization and purulent infiltration with 

 which we have become acquainted as stages of croupous pneumonia ; 

 although fibrinous exudation never accompanies the cell-growth in 

 catarrhal pneumonia. Abscesses may form as one of the rarer sequelse of 

 this disease, while caseous infiltration is a far more common result of 

 this disorder than of croupous pneumonia. Finally, catarrhal pneumonia 

 often results in neoplastic formation of connective tissue with con- 

 secutive wasting and shrinking of the parenchyma. At all events, 

 Bartels, in a series of cases, in which the disease had run a more chronic 

 course than usual, found, instead of the changes described above, that 

 large portions of the lower lobes had acquired a pale, bloodless, strik- 

 ingly compact and firm consistence. The cut surface also showed a 

 pale-blue color, and presented a homogeneous, smooth, dry appearance. 

 The parts of the lung thus altered could not be inflated. The bronchi 

 were filled by yellowish caseous plugs. The most striking point was 

 the great increase of the interstitial connective tissue. The condensed 

 portions were traversed by thick grayish-white cords, and bands of 

 connective tissue, which ran in different directions, crossing one another 

 repeatedly, and forming a well-defined network. This termination of 

 catarrhal pneumonia is analogous to the induration which we have 

 described as occurring in croupous pneumonia. 



SYMPTOMS AND COURSE. It is difficult to draw up a comprehen- 

 sive picture of catarrhal pneumonia, as the disease is never of primary 

 origin, but always supervenes upon a catarrhal bronchitis or a collapse 

 of the lung proceeding from bronchitis, and its only symptoms consist 

 hi modifications more or less distinct of the symptoms of the disorder 

 by which it has been preceded. With the exception of the physical 

 signs, which, however, are not always characteristic, the kind and man- 

 ler of the cough and the character of the fever furnish the most im- 

 portant data for the recognition of the complication which has set in. 

 It is highly suspicious if the sick child fear to cough, or when we find, 

 by its complaints, or, in a very young child, by the distressed expression 

 of its countenance, during coughing, that coughing gives it pain. We 



