Lesions of bronchopneumonia which are frequently found in the autopsies under consideration may be conveniently designated by descriptive terms, indicative of their location in the lung tissue. These lesions, of which two or more often occur in the same lung, are:
1. Peribronchiolar consolidation with which the inflammatory exudate is limited to the alveoli in the immediate neighborhood of the bronchioles.
2. Hemorrhagic peribronchiolar consolidation in which gray patches of peribronchiolar pneumonia occur upon a deep red background produced by hemorrhage into alveoli. Pfeiffer believed that this lesion was characteristic of influenza.
3. Lobular consolidation with which consolidation is limited to lobules or groups of lobules.
4. Peribronchial pneumonia with which small bronchi are encircled by pneumonic consolidation.
Each one of these lesions will be discussed separately.
Following is a list of the bacteria which have been isolated from the consolidated lung of individuals with bronchopneumonia unaccompanied by lobar pneumonia or by suppuration:
| B. influenzæ | 1 |
| Pneumococci | 5 |
| S. hemolyticus | 5 |
| S. viridans | 1 |
| B. influenzæ, pneumococci | 9 |
| B. influenzæ, S. hemolyticus | 4 |
| B. influenzæ, staphylococci | 4 |
| Pneumococci, S. hemolyticus | 1 |
| Pneumococci, staphylococci | 2 |
| S. hemolyticus, staphylococci | 1 |
| S. hemolyticus, B. coli | 1 |
| Staphylococci, S. viridans | 1 |
| Staphylococci, B. coli | 1 |
| B. influenzæ, pneumococci, staphylococci | 1 |
| B. influenzæ, pneumococci, S. viridans | 1 |
| B. influenzæ, S. hemolyticus, staphylococci | 2 |
| B. influenzæ, pneumococci, staphylococci, S. viridans | 1 |
| No microorganisms found | 6 |
| 47 |
The similarity of this list to that representing the bacteriology of bronchitis is evident; there is the same multiplicity of microorganisms and the frequent occurrence of mixed infections. B. influenzæ is much less frequently found in the lung. The relative pathogenicity of the large group of microorganisms enumerated above is better indicated by the following list which shows what microorganisms have penetrated into the blood in autopsies performed on individuals with bronchopneumonia:
| Pneumococci | 20 |
| S. hemolyticus | 23 |
| S. viridans | 1 |
| Pneumococci, S. hemolyticus | 2 |
| No bacteria found | 25 |
| Total | 71 |