Abstract
The secretory tubule of the horse sweat gland consists of a single layerof columnar or cuboidal cells and a myoepithelium. The gland cells are pro-vided with a brush border at their luminal end and have a number of mito-chondria and a variable amount of melanin pigment granules, but no secretionantecedents in the form of granules in their cytoplasm. There is no evidencethat they normally form secretion by pinching off or disintegration of theirdistal cytoplasm. The myoepithelial cells are thin and flat compared with thoseof the human sweat glands.
The gland cells do not contain glycogen, whereas the myoepithelial cellscontain some of it. A small amount of ribonucleic acid and only traces ofionic iron are detected in the cytoplasm of the former. Alkaline phosphatasesare demonstra ted in the brush border, the narrow zone of cytoplasm beneathit and the nucleus of the gland cells and in the myoepithelium.
