An account is given of a study of some of the histological changes in the lung in chronic bronchitis. The bronchial tree alone is discussed in this article, the author stating that the changes in the blood vessels and the occurrence of emphysema wilt form the subject of a further communication.

The material was obtained from lungs of 16 patients known to have had chronic bronchitis, from mucosal biopsies in 6 cases of chronic bronchitis in. order to obtain examples of the early stage of the disease and from 8 pncumonectomy specimens showing both chronic bronchitis and bronchogenic carcinoma. The control matter came from 10 cases with no history of bronchitis.

The lungs were examined partly by single sections from selected areas and partly by serial sections in order to trace the relationship between bronchioles and alveoli. From the 16 necropsy specimens 225 blocks were examined and 14 blocks from 10 of the cases were examined serially. Every third slide was stained by the Verhoeff-van-Gieson method, and the others were stained to show mucin and fibrin.

In the early cases the principal change was hypertrophy of the mucus-secreting elements (glands and goblet cells) and the finding of an excess of mucus in the air-passages. More advanced cases showed similar changes, but in addition the following changes were observed in the bronchioles-hypertrophy of goblet cells, purulent bronchiolitis, formation. of abscess cavities, obliteration of the lumen and dilatation (diffuse or localized). In the alveoli small foci of Str. pneumoniae, organization of pneumonic exudate, oedema and collapse were seen with mucus and pus lying in alveolar spaces: there were also emphysematous areas. Serial sections demonstrated the loss of the normal bronchiolar and alveolar pattern, and although each single focus showing these changes may be small the functional disturbance may become irreversible and successive attacks lead to the destruction of so many units of respiration that severe incapacity results.

[This paper is well illustrated by photomicrographs in colour and by diagram: the paper by OSWALD, reviewed above (p. 451), is partly based on the findings given here and the two papers are complementary.] G. Stewart Smith.