Mass. Gen. Laws ch. 231, § 138: Amendment of pleadings; notice and hearing requisite to bind certain persons; appeal

Section 138. No subsequent attaching creditor or purchaser of property attached, other than parties to the record, shall be bound by an amendment of the pleadings which substantially affects his rights unless he has had due notice of the motion for leave to amend and unless he has had an opportunity to be heard thereon. Such persons shall also have the right of appeal.