The right of any person to an estate in land by succession as heir acquired after the commencement of this Act may, at any time within twenty years of his infeftment as heir and his entering into possession of such estate, but not thereafter, be challenged by any one who would have been entitled to challenge the decree of service of such person had he expede a service according to the practice existing prior to this Act; and, in the absence of evidence to the contrary, the date of his infeftment shall, for the purpose of this limitation, be assumed to be the date of entering into possession; and such challenge may be made by an action to negative or set aside the alleged right of succession, or to reduce any title expede in virtue of such alleged right.