(a) The interest of the beneficiary of any trust may be assigned or otherwise transferred, except that:

(1) The right of a beneficiary of an express trust to receive the income from property and apply it to the use of or pay it to any person may not be transferred by assignment or otherwise unless a power to transfer such right, or any part thereof, is conferred upon such beneficiary by the instrument creating or declaring the trust.

(2) The proceeds of a life insurance policy which, under a trust or other agreement, are upon the death of the insured left with the insurance company may not be (A) transferred, (B) subject to commutation or encumbrance or (C) subject to legal process except in an action for necessaries, if provisions to such effect were incorporated in such trust or other agreement.

(b) Notwithstanding subparagraph (a) (1):

(1) The beneficiary of an express trust to receive income from property and apply it to the use of or pay it to any person may, unless otherwise provided in the instrument creating or declaring such trust, transfer any amount in excess of ten thousand dollars of the annual income to which the beneficiary is entitled from such trust to the spouse, issue, ancestors, brothers, sisters, uncles, aunts, nephews or nieces of the beneficiary, or to a trustee, committee, conservator, curator, custodian, guardian of the property of a minor, or the donee of a power during minority for the benefit only of any such person bearing such relationship to the beneficiary, provided that such transfer is evidenced by a written instrument signed and acknowledged by the beneficiary and delivered to the trustee of the trust, together with an affidavit by the beneficiary that such transfer and any like transfer concurrently in effect are for all or part of the excess over ten thousand dollars of the annual income from such trust to which such beneficiary is entitled, and that he has not received and is not to receive any consideration in money or money's worth for the transfer.

(2) Any such transfer shall be effective in any year only as to income from such trust in excess of ten thousand dollars, and for this purpose all previous like transfers applicable to a given year shall be taken into account. In the event that two or more transfers are made in or for any year in a total amount exceeding the income from such trust properly transferable hereunder, transferees shall be preferred in the order in which the instruments of transfer were delivered to the trustee.

(3) A trustee shall be exonerated and fully discharged for any payment made to a transferee in reliance on the affidavit of a beneficiary described in subparagraph (1).

(4) The provisions of this paragraph do not apply to subparagraph (a) (2):

(c) A transferee of income may, if he has not received or is not to receive any consideration in money or money's worth therefor, make a further transfer of such income only to one or more of the permissible transferees referred to in subparagraph (b) (1), other than a prior transferor; provided, however, that upon the death of a transferee any income not so transferred by him shall be an asset of his estate, subject to his testamentary disposition or passing to his distributees under the statutes of descent and distribution.

(d) The beneficiary of an express trust to receive the income from property and apply it to the use of or pay it to any person is not precluded by anything contained in this section from transferring or assigning any part or all of such income to or for the benefit of persons whom the beneficiary is legally obligated to support.