The state shall be divided into judicial circuits along county lines in each of which there shall be elected one or more circuit judges as provided by law. Sessions of the circuit court shall be held at least four times in each year in every county organized for judicial purposes. Each circuit judge shall hold court in the county or counties within the circuit in which he is elected, and in other circuits as may be provided by rules of the supreme court. The number of judges may be changed and circuits may be created, altered and discontinued by law and the number of judges shall be changed and circuits shall be created, altered and discontinued on recommendation of the supreme court to reflect changes in judicial activity. No change in the number of judges or alteration or discontinuance of a circuit shall have the effect of removing a judge from office during his term.