The duct system of the lachrymal salt gland of the green sea turtle,Chelonia mydas

Summary The duct system of the lachrymal salt gland of the green sea turtle comprises central canals, secondary ducts and a sac-like main duct. Distally the central canals consist of large columnar cells with lateral membranes folded into plicae which interdigitate in adjacent cells to form complex intercellular spaces. More proximally the central canals, secondary ducts and main duct consist of epithelia which are stratified or pseudostratified. The cells of these epithelia are separated by wide and complex inter-cellular spaces: they are joined by frequent maculae adherentes junctions. Complex intracellular webs of tonofilaments are associated with these junctions. At the luminal border of the epithelia of the secondary and main ducts is a layer of mucocytes. The mucocytes increase in density towards the proximal extremity of the main duct and secrete a thick luminal layer of mucus. The duct system is very well vascularised. It is suggested that it is unlikely to be merely a passive conduit and that it may have a role in the modification of the fluid secreted by the gland.