25 U.S.C. § 408

In any case where an Indian has an allotment of land, or any right, title, or interest in such an allotment, the Secretary of the Interior, in his discretion, may permit such Indian to surrender such allotment, or any right, title, or interest therein, by such formal relinquishment as may be prescribed by the Secretary of the Interior, for the benefit of any of his or her children to whom no allotment of land shall have been made; and thereupon the Secretary of the Interior shall cause the estate so relinquished to be allotted to such child or children subject to all conditions which attached to it before such relinquishment.