The only form of pustular inflammation occurring in the air-passages is the variolous, which, however, is very perfectly developed.. It is usually present whenever the variolous process exhibits considerable intensity, and when the skin is covered with an abundant eruption of the exanthema. It appears in the form of simple pustules on the mucous membrane of the epiglottis and adjacent soft palate, of the larynx, and the trachea, and not unfrequently in the bronchi and their primary branches. The pustules are soft, easily rubbed off, not unfrequently confluent, and when removed leave a superficial, concave, roundish spot, where the mucous membrane presents a dark-red or livid tint, and an appearance of excoriation. Between these spots it presents various degrees of redness and thickening, and is coated with a tough plastic mucus, - a croupous exudation; moreover it is much swollen, and together with the submucous areolar tissue, exhibits signs of serous infiltration. Very intense confluent pustulation may give rise to variolous ulceration.