A deed of gift by D in favour of his daughter M for life provided that he property should go to her male issue, and in default, to D’s sons. One of D’s two sons induce a purchaser to buy his sister’s property and the same deed was attested by the other son. M dies without leaving any male issue and D’s son filed a suit to recover the property from the purchaser. State giving reasons, whether the plea of estoppels would be available to the defendant against the plaintiff?      (10 Marks)