A WART (fig. 74) depends chiefly on a diseased state of the papillary stratum of the skin. The papillæ become coarse and grow up beyond the level of the surrounding skin, so as to present an uneven or “warty” surface. They carry a layer of cuticle before them. This layer is usually thin, so that the wart bleeds easily when it is rubbed. Sometimes, however, it is very thick and hard like a piece of horn. We, now and then, hear of a horn growing upon some part of the body, perhaps on the forehead. Such a horn is, usually, nothing more than a conical mass of cuticle formed upon the surface of a large wart. Warts are generally caused by something irritating the skin, as dirt or soot rubbed into the cuticle. For this reason they are more frequent upon the hands than upon other parts of the body. In a CORN (fig. 73), also, the papillæ are somewhat enlarged; and this accounts in part for the great tenderness of corns. But the primary and essential feature of a corn is a thickened state of the cuticle. This is caused by too great rapidity in its formation, and is, usually, dependent upon pressure, especially if the pressure be combined with some friction. Hence corns are most commonly found upon the foot, and upon the parts of the foot, where the skin is subject to pressure and rubbing against the shoe. The drawing shows the appearance presented by a vertical section through a corn and through a small portion of the skin on either side. The accumulated layers of cuticle are seen, and the enlarged papillæ shooting up into them. I need scarcely add that it is owing to ignorance, or something worse, when corn-cutters talk of curing the malady by taking out the _roots_; for, corns, evidently, have no roots.