x on the
transfer of contingent remainders, undiminished by the value of an
intervening life estate but not payable until after the death of the
life tenant, is valid.[466] Also, when a power of appointment has been
granted by deed, transfer tax upon the exercise of the power by will is
not a taking of property without due process of law, even though the
instrument creating the power was executed prior to enactment of the
taxing statute.[467] Likewise when a transfer tax law did not become
effective until after a deed creating certain remainders had been
executed, but the State court applied the tax on the theory that the
vesting actually occurred after the tax law became operative, no denial
of due process resulted. "* * *, the statute unquestionably might have
made the tax applicable to this transfer, * * * [and the Court need]
* * * not inquire * * * into the reasoning by which * * *" the State
held the statute operative.[468]

On the other hand, when remainders indisputably vest at the time of the
creation of a trust and a succession tax is enacted thereafter, the
imposition of said tax on the transfer of such remainder is
unconstitutional.[469] But where the remaindermen's interests are
contingent and do not vest until the donor's death subsequent to the
adoption of the statute, the tax is valid.[470] Another example of valid
retroactive taxation is to be found in a New York statute amending a
1930 estate tax law. The amendment required inclusion in the decedent's
gross estate, for tax computation purposes, of property in respect of
which the decedent exercised after 1930, by will, a nongeneral power of
appointment created prior to that year. The amendment reached such
transfers under powers of appointment as under the previous statute
escaped taxation. In sustaining application of the amendment, the Court
held that the inclusion in the gross estate of property never owned by
the decedent, but appointed by her will under a limited power which
could not be exercised in favor of the decedent, her creditors, or her
estate, did not deny due process to those who inherited the decedent's
property, even though, because the tax rate was progressive, the net
amount they inherited was less than it would have been if the appointed
property had not been included in the gross estate.[471] In summation,
the Court has noted that insofar as retroactive taxation of vested gifts
has been voided, the justification therefor has been t