Section 123. No land originally acquired in any manner under the provisions of any previous Act, ordinance, royal order, royal decree, or any other provision of law formerly in force in the Philippines with regard to public lands, terrenos baldios y realengos, or lands of any other denomination that were actually or presumptively of the public domain, or by royal grant or in any other form, nor any permanent improvement on such land, shall be encumbered, alienated, or conveyed, except to persons, corporations or associations who may acquire land of the public domain under this Act or to corporate bodies organized in the Philippines whose charters authorize them to do so: Provided, however, That this prohibition shall not be applicable to the conveyance or acquisition by reason of hereditary succession duly acknowledged and legalized by competent courts; Provided, further, That in the event of the ownership of the lands and improvements mentioned in this section and in the last preceding section being transferred by judicial decree to persons, corporations or associations not legally capacitated to acquire the same under the provisions of this Act, such persons, corporations, or improvements shall be obliged to alienate said lands or improvements to others so capacitated within the precise period of five years; otherwise, such property shall revert to the Government.