The legislature may from time to time place monies into endowment funds for higher education scholarships and for improving the quality of higher education, which funds shall remain inviolate. The earnings of the funds shall be used for the purposes specified in this section, but the legislature may from time to time by law regulate the manner in which the earnings are expended. The legislature may also provide for use of the earnings to protect the funds from inflation and to even fluctuations in earnings over time. The funds may be invested in the same manner as other permanent funds of the state.