Pursuant to the rules or instructions adopted by a majority of the judges of the superior court, the jury commissioner shall return to the judges the list of persons recommended by him for grand jury duty. The judges of the superior court shall examine the jury list so returned and from such list a majority of the judges may select, to serve as grand jurors in the superior court of the county during the ensuing year or until a new list of jurors is required, such persons as, in their opinion, should be selected for grand jury duty. The persons so selected shall, in the opinion of the judges selecting them, be persons suitable and competent to serve as jurors, as required by

law.