Massachusetts General Laws Part III. Courts, Judicial Officers and Proceedings in Civil Cases (Ch. 211-262) Ch. 221, § 64

He shall attend the law sittings of the court unless excused therefrom by the chief justice, make true reports of decisions upon all questions of law argued by counsel, prepare them for publication with suitable head notes, tables of cases and indexes, furnish them to the publisher, and superintend the correction, proof reading and publication thereof. He shall in his discretion report the several cases more or less at large according to their relative importance, so as not unnecessarily to increase the size or number of the volumes of reports. The reports of all decisions argued and determined before September first in each year shall be published within ninety days thereafter.