From the Epicurious food dictionary,: "A classic English preparation that begins with cut pieces of HARE that are soaked in a red wine-juniper berry marinade for at least a day. The marinated meat is well browned, then combined in a casserole (traditionally a heatproof crock or jug) with vegetables, seasonings and stock, and baked. When the meat and vegetables are done, the juices are poured off and combined with cream and the reserved hare blood and pulverized liver. The strained sauce is served over the "jugged" hare and vegetables.
"I am not fond of jugged hare for dinner, either as a light entrée or as a pièce de résistance; but this accomplished attendant had the art of presenting you such a dish in a manner that persuaded you, for the time, that it was worthy of your serious consideration. The hare, by the way, before being subjected to the mysterious operation of jugging, might have been seen dangling from a hook in the bar of the inn, together with a choice collection of other viands."
"An English Winter Watering-Place," p 159 of the Oxford paperback edition of English Hours