Section 6. The Legislature shall provide for the election by the qualified electors of each county of the following county officers:
A clerk of the circuit court, a sheriff, constable, a county assessor of taxes, a county tax collector, a county treasurer, a superintendent of public instruction and a county surveyor.
The term of office of all county officers mentioned in this section shall be four years, except, that the term of office of the county assessor of taxes, county tax collector and county treasurer, shall be for two years, until the general election in November, 1906, at which election they also shall be elected for terms of four years each, and thenceforth all county officers named in this section shall be elected for terms of four years. Their powers, duties and compensation shall be prescribed by law.