SECTION 4. The supreme court of this state, with the jurisdiction and power prescribed in this constitution, shall consist of one chief justice and four associate justices to be elected by the qualified electors of the state at such times, and in such manner as the legislature may provide, and such court so constituted shall not be changed or discontinued by the legislature. The chief justice and associate justices of the supreme court now in office shall hold their offices for the remainder of the terms for which they were respectively elected, and until the election and qualification of the two additional associate justices herein proved for, shall constitute the supreme court of the this state. The legislature shall at its first annual session after the adoption of this amendment, provide by law for the election of the two additional associate justices hereby required, and their successors and for the election of the successors of the chief justice and associate justices now in office, and for classifying the two additional associate justices first elected, so that the term of the office of one of them shall be four years and the other six years. Term of office of the chief justice and of each associate justice of the supreme court elected after the adoption of this amendment, except as herein otherwise provide, shall be six years.