Section 13. Unless the constitution of the State otherwise provides, a State legislature has authority to extend or limit the boundaries of a county, enlarge or diminish its area, divide the same into two or more counties, or consolidate two or more counties into one.6 State constitutions, however, very frequently contain provisions limiting the area of counties, each to a certain number of square miles, and inhibiting the reduction of counties below that amount and forbidding the taking of any territory from any county less than the prescribed area, and where a State constitution thus prescribes the area of counties, an act of the legislature diminishing such area is unconstitutional and may be treated as null and void by a county court.7