[Light and electron microscopic studies of the lacrimal gland of the monkey (Macaca mulatta)].

The following results were obtained by light and electron microscopical investigations of the lacrimal gland of the rhesus monkey (Macaca mulatta): 1. The lacrimal gland of the monkey is a tubulo-acinous gland having intra and extra lobar excretory ducts. Intercalated and striated ducts are lacking. 2. The secretory epithelium consists of two cell types: a) cells which have a light cytoplasm and dark secretory granules, b) cells with a dark cytoplasm and granules of different electron density. 3. The difference in the types of cells observed and in the appearance of secretory granules reflect classes due to a secretory cycle. 4. Both cell types have a parenchymal innervation, the cells with dark cytoplasm being only scarcely innervated. 5. The parenchymal innervation is cholinerg. 6. The epithelium of the intra and inter lobular excretory ducts shows secretory activity. It is surrounded by myoepithelial cells and receives a parenchymal cholinerg innervation.