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Haller gave this name to two very fine vessels, which spread their ramifications on the parietes of the umbilical vesicle. There is an omphalo-mesenteric artery and vein. The omphalo-mesenteric artery is a branch of the superior mesenteric ;-the vein empties itself into the trunk, or into one of the branches of the superior mesenteric. Velpeau affirms, that they inosculate with a branch of the second or third order of those great vessels, with those in particular that are distributed to the caecum, and he regards them to be the vessels of nutrition of the umbilical vesicle. They are occasionally met with in the foetus, at the full period, under the form of whitish filaments, which extend from the mesenteric vessels to the umbilicus.