ELECTRON MICROSCOPY OF THE DUCT, AND ESPECIALLY THE "CUTICULAR BORDER" OF THE ECCRINE SWEAT GLANDS IN MACACA MULATTA

The coiled duct of the eccrine sweat glands consists of two or three layers of epithelial cells concentrically a r ranged around the lumen (Fig. 1). The superficial cells have a fibrous luminal border ; the peripheral cells, usually contain moderate amounts of glycogen and rest on a poorly developed basement membrane . Numerous blood vessels and unmyel ina ted nerves adhere to the coiled duct. The Luminal Border: The low microvilli on the inner surface of the lumina l cells are surrounded by a plasma membrane composed of two adielectronic lines separated by a light band. The outer dense line is ~ 5 0 A thick, the th inner one ~ 2 0 A; the light band between them is about 25 A wide. A few smooth surfaced vesicles in the cytoplasm benea th the microvilli may result from