“…Lymphocytes have been reported within the epithelium of the gut (Darlington & Rogers, 1966;Toner & Ferguson, 1971), the thyroid (Toujas & Guelfi, 1969), the bronchi (Bienenstock, Johnston & Percy, 1973), the biliary tract (Evett, Higgins & Brown, 1964;Hayward, Freston & Bouchier, 1968), the urinary bladder (Lefevre, Reincke, Arbas & Gennaro, 1973), the submucosal glands of the bronchi (Meyrick & Reid, 1970) and in the epidermis (Fichtelius, Liden & Groth, 1971). It seems likely that lymphocytes are present in nearly all epithelia on external surfaces or lining internal surfaces, but little is known about their function, their life-span, or their fate.…”