Scanning electron microscope studies of some normal and diseased conditions of mammalian skin as revealed in leather manufacture.

Sheep, goat and bovine skins, as leather, were examined. The surface contours of dermal response to sunburn, facial eczema, rape scald, and demodicosis are illustrated. In sunburn, demodicosis and rape scald, finger-like and ridge pattern projections had developed. In the photo-sensitive condition of rape scald and facial eczema distension was apparent, and in addition in rape scald reactions of contrasting nature involving hair follicles indicated a considerable disorientation of the skin. The transition from str. basale to str. corneum in bovine epidermis has been examined in leather from which the epidermis had unintentionally been incompletely removed in the course of manufacture, during attack on the keratinous tissue by hydrosulphide ions at high hydroxyl ion concentration. A "pore" presumably related to the position of the nucleus was observed in the outer surface of each of the cells in each layer exposed by the attack. The walls of the basal and adjacent cells appeared remarkably sturdy. As judged from the basal cells the intercellular cement (cell coating) disappeared before the cell wall degraded, but intercellular bridges remained clearly visible in the prickle cell layer, while towards the exterior, adjacent cell walls appeared more closely knit and the str. corneum (residues of which were observed around the follicles) appeared to lie in sheets. Discrete and fibrous cell components were exposed. At the latest degree of degradation observed in the basal cells the wall had reduced to a fibrous network.