According to the later clinical course, the basal-celled carcinomata may be divided into seven groups-1, the flat rodent ulcers; 2, the nodular; 3, the rolled-edge; 4, the depressed scar-like cancer; 5, the morphea-like; 6, the fungating; 7, the deep ulcerating. All of these types may run more or less rapid courses, according to the rapidity of neoplastic growth, the nutrition of the part, and the resistance of the invaded tissue. If the cancer cells multiply more rapidly than they are able to invade, a fungous growth results. At times spontaneous healing may take place in the center, or even around the edges, but the whole growth never heals.

Fig. 21.-This old lady has a flat basal-celled carcinoma of the nose, that has recurred after being curetted and cauterized with silver nitrate one year ago. The growth originally developed from a semi-glohular wart similar to the one on the upper Hp. (Author's collection).