The salt gland of the herring gull (Larus argentatus) is a large, paired gland on top of the skull. On each side 2 ducts lead to the anterior nasal cavity. When the gland is secreting, its discharge comes out through the nares and drips off from the tip of the beak. The gland has long, tubular lobes, each with a central canal. Tubulous glands radiate from the central canal. The gland cells have a striated or lamellated cytoplasm, and seem to have secretory canaliculi. The blood supply is mainly from arteria ophthalmica interna. Within the gland the capillary blood flow is in a direction opposite to that of the secreted fluid. The innervation of the gland is from a ganglion of predominantly parasympathetic nature. The salt glands of other marine birds have the same characteristic structurewith the secreting tubules radiating out from a central canal.