In the year nineteen hundred and seventy-five and every tenth year thereafter a census of the inhabitants of each city and town shall be taken. Said census shall specify the number of inhabitants residing in each precinct of each town and in each precinct and ward of each city. Said census shall be the basis for determining the representative districts for the ten year period beginning with the first Wednesday in the fourth January following the taking of said census; provided that such districts as established based on the census in the year nineteen hundred and seventy-one shall terminate on the first Wednesday in January in the year nineteen hundred and seventy-nine.] [See Amendments, Arts. CIX and CXVII.]

The House of Representatives shall consist of one hundred and sixty members. The General Court shall, at its first regular session after the year in which said census was taken, divide the Commonwealth into one hundred and sixty representative districts of contiguous territory so that each representative will represent an equal number of inhabitants, as nearly as may be; and such districts shall be formed, as nearly as may be, without uniting two counties or parts of two or more counties, two towns or parts of two or more towns, two cities or parts of two or more cities, or a city and a town, or parts of cities and towns, into one district. Such districts shall also be so formed that no town containing less than twenty-five hundred inhabitants according to said census shall be divided. The General Court may by law limit the time within which judicial proceedings may be instituted calling in question any such division. Every representative, for one year at least immediately preceding his election, shall have been an inhabitant of the district for which he is chosen and shall cease to represent such district when he shall cease to be an inhabitant of the Commonwealth. The manner of calling and conducting the elections for the choice of representatives, and of ascertaining their election, shall be prescribed by law.