Section 44A. There shall be in the department of civil service and registration a board of registration of architects, in this and the following three sections called the board, to be appointed by the governor, consisting of five members, citizens of the commonwealth, four of whom shall each have been engaged in the practice of architecture for a period of ten years or more prior to his appointment, and shall be registered architects. The fifth member shall be a representative of the public, subject to the provisions of section nine B. As the term of office of a member of the board expires, his successor, qualified as aforesaid, shall be appointed by the governor, to serve for five years. Each member shall continue to serve until the qualification of his successor. The governor may also fill any vacancy in the board for the unexpired portion of the term.