Massachusetts Constitution Pt. 2, Ch. I, § 2, Art. 3

ART. III. And that there may be a due convention of senators on the [last Wednesday in May] annually, the governor with five of the council, for the time being, shall, as soon as may be, examine the returned copies of such records; and fourteen days before the said day he shall issue his summons to such persons as shall appear to be chosen by [a majority of] voters, to attend on that day, and take their seats accordingly: provided nevertheless, that for the first year the said returned copies shall be examined by the president and five of the council of the former constitution of government; and the said president shall, in like manner, issue his summons to the persons so elected, that they may take their seats as aforesaid.