The right to a particular part is an inherited one.

No polite offering of a choice to an honoured guest, no suggestion of the leg or wing.

You may loathe the leg of a bird as food, but at a black fellow's feast, if convention ordains that as your portion, have it you must; just as each rank in society had its invariable joint in early mediaeval Ireland.
The seeds of Noongah--a sterculia--and Dheal, were ground on their flat dayoorl-stones and made into cakes, which they baked, first on pieces of bark beside the fire to harden them, then in the ashes.

These dayoorl, or grinding-stones, are handed down from generation to generation, being kept each in the family to whom it had first belonged.

Should a member of any other use it without permission, a fight would ensue.