Mass. Gen. Laws ch. 29 § 48A
Facsimiles of the signature of the governor on original issues or transfers of bonds or notes of the commonwealth shall have the same validity and effect as the governor's written signature, and facsimiles of the seal of the commonwealth may be used on bonds and notes of the commonwealth and shall have the same validity and effect as though said seal were impressed thereon. Interest coupons, if any, attached to any bond or note of the commonwealth may bear the facsimile signature of the state treasurer. If any officer whose signature or a facsimile of whose signature appears on any notes, bonds or coupons shall cease to be such officer before the delivery of, and receipt of proceeds from the borrowing evidenced by, such notes or bonds, such signature or such facsimile shall nevertheless be valid and sufficient for all purposes as if such officer had remained in office until such delivery and receipt of proceeds.
Mass. Gen. Laws ch. 29, § 48A