[mod.L. epithēlium, f. Gr. ἐπί upon + θήλη teat, nipple.]
1. Anat. A non-vascular tissue forming the outer layer of the mucous membrane in animals.
1748. Hartley, Observ. Man, I. ii. 117. The Impressions can easily penetrate the soft Epithelium.
1842. Prichard, Nat. Hist. Man (1845), 87. The different appearances of the epithelia or outer membranous linings of all the surfaces.
1872. Mivart, Elem. Anat., 237. The superficial layer of the skin so reflected inwards is termed epithelium, which is thus but a modified epidermis.
2. Bot. An epidermis consisting of young thin-sided cells, filled with homogeneous transparent colorless sap. (Treas. Bot.)
1870. Bentley, Bot., 49. The canal of the style, and the stigma of Flowering Plants are also covered by a modified epidermis … to which the name of Epithelium has been given by Schleiden.
