77-3-106. Disposition of royalties, fees, and penalties. All fees and penalties collected under this part shall be credited to the state general fund; all rentals shall be credited to the income fund of the grant to which the land belongs; and all moneys collected as royalties shall be credited to the permanent fund arising from the grant to which the land belongs under each particular permit or lease; provided, however, that all rentals and royalties received from "mortgage lands" shall be credited to the same fund or funds as other receipts from such lands and that all rentals and royalties received under or in connection with a lease or permit on other lands or mineral rights not acquired through any grant to the state of Montana from the United States shall be paid into the same funds into which such receipts are paid when the land is part of the grant for the benefit of the public schools of the state of Montana.