The Board may terminate the Plan at any time; provided , that termination of the Plan shall not adversely affect the rights of a Director or beneficiary thereof with respect to amounts previously deferred under the Plan without the consent of such Director. The Board may amend the Plan at any time and from time to time; provided , however , that no such amendment shall materially and adversely affect the rights of any Director or beneficiary thereof with respect to amounts previously deferred under the Plan.