represent in general a somewhat late stage of syphilis, and one in which are found patients who are cachectic, poorly fed, or improperly treated or cared for (Pl. 11). Here the pustules tend to enlarge, to develop in more limited and circumscribed areas, to involve a greater depth of the corium and the subcutaneous tissue, and to be accompanied by symptoms of malignancy. The area of each pustule or group of pustules assumes an angry look; the pus formed is inspissated, hemorrhagic, and commingled with pultaceous sloughs; the resulting crusts are blackish, the scars are persistent, and the pigmentation is deforming and slow to disappear. The ulcers left by the largest and most formidable of these lesions are of the type of the syphilitic ulcer in general. They have clean-cut, punched-out edges, a floor covered with an adherent pus-bathed slough, an engorged base, and a roof at times constituted of the successive desiccations of pus formed from the spreading ulcer beneath, so that a stratified conical crust with limpetshell aspect is produced. Here, again, the circular, semicircular, horseshoe-shaped, and other combinations of the circle so oddly characteristic of the ulcers of syphilis are constantly encountered.

The oyster-shell-like crusts seen in var us sizes in so many of the pustular syphilodermata, especially over large-sized lesions, were once supposed to be produced