Wash and split the herrings and remove the backbone. Mix together the breadcrumbs, suet, parsley and lemon rind, season to taste and add enough milk to moisten. Season each herring with salt and pepper, spread on a thin layer of the forcemeat and roll up tightly, beginning with the neck. Pack closely in a greased pie-dish, cover with greased paper and bake 30–40 min. in a moderate oven (350° F., Gas 4). Serve hot.