Massachusetts General Laws Part I. Administration of the Government (Ch. 1-182) Ch. 30, § 6A

If any member of a permanent state board or commission or of a board or commission appointed under an interstate compact who serves as such by virtue of holding any other office or position is unable by reason of absence or disability to perform his duties as such member, he may, by a writing filed in the office of such board or commission, designate an officer or employee in his department who shall, without additional compensation therefor, perform such duties in case of and during such absence or disability, but a person so designated shall have no authority to make any appointments or removals. Any such designation may in like manner be revoked at any time.