When a sole or last surviving trustee has died or shall have died possessed of an estate in land held in trust, and there shall be .no contrary provision in the deed of trust, and no contrary order shall be made by the Court of Session, the heir-at-law of such trustee, being of full age and not subject to any legal incapacity, may complete a title thereto as trustee in his room in the manner provided- by " The Titles to Land Consolidation (Scotland) Act, 1868," with respect to the title of any other heir, but such heir-at law shall not, unless under the orders of the court or with the consent and approval of all the beneficiaries (being all above age and not subject to any legal incapacity), administer the trust, but, in the absence of such order or such consent and approval, shall be bound forthwith to make over the lands to any trustee or judicial factor appointed by the court for administering the purposes of the trust, or to any trustee or trustees appointed by any person who has power under the trust deed to make such appointment, or to any person or persons whom the beneficiaries, as aforesaid, may have concurred in appointing to execute the remaining purposes of the trust, or to the beneficiaries themselves if the whole trust purposes except the conveyance of the lands in terms of the trust have been or shall have been executed; and such heir-at-law shall, unless he acts as a trustee under such orders or with such consent and approval, be in no way responsible as trustee in regard to the administration of the trust, or of the lands to which he may have made up title as aforesaid.