Michigan constitution
Article VI
Section 15

In each county organized for judicial purposes there shall be a probate court. The
legislature may create or alter probate court districts of more than one county if approved in
each affected county by a majority of the electors voting on the question. The legislature may
provide for the combination of the office of probate judge with any judicial office of limited
jurisdiction within a county with supplemental salary as provided by law. The jurisdiction,
powers and duties of the probate court and of the judges thereof shall be provided by law. They
shall have original jurisdiction in all cases of juvenile delinquents and dependents, except as
otherwise provided by law.