It consists in a wasting of the textures from the corrosive quality of the exudate. Herein ulcerous consumption of the textures differs from the loss of substance which inflamed textures undergo, within the best conditioned exudates, through necrosis and absorption.

To be productive of such a wasting process, the exudate must needs be fluid, whether originally so, or liquefied out of a solid blastema. Its corrosive influence upon the textures is sufficient to confirm its character as genuine ichor.

The mode in which textures in contact with ichor become destroyed, varies with the principle upon which its corrosive nature depends. The exulceration takes sometimes an acute, sometimes a chronic course. Large textural masses are not rarely destroyed within a short space of time. The destruction is marked, now by superficial extension, now by a burrowing propensity. In the former instance, it depends frequently upon a special relation of the inflammatory process to superficial textural expansion. In the other case, some heterologous formation, reproduced again and again, at the base of the ulcer, upholds the inflammation, and with it the ichorous discharge.

In the chronic form, the ulcer, like the pus-membrane, simulates, in the production of flesh-granules, a natural process of secretion.

All textures are not equally prone to ulcerative destruction. Under like circumstances, tender, young, budding growths are the most readily destroyed.