Section 51. A trustee appointed under section forty-nine shall give bond in such form and for such amount as the court appointing him may order, and he shall receive and hold, invest or apply the proceeds of any sale or mortgage made by him for the benefit of the persons who would have been entitled to the land if such sale or mortgage had not been made, and the probate court of any county where any part of such land is situated shall have jurisdiction of all matters thereafter arising relative to such trust.