Settlor died in 1918, leaving most of his estate in trust for his two unmarried sisters during their joint lives and the life of the survivor. Upon the death of the survivor, the trust corpus was to be divided among all settlor's brothers and sisters or their issue. At the time of Settlor's death, all his brothers and sisters were alive. Mary, the surviving joint life tenant, was the last of all the brothers and sisters at the time of her death in 1951.