12. Any such certificate or statement may direct the issue of any number of summonses; but the name of every person on whom any summons is intended to be served shall be stated therein; and no summons shall be issued without payment of the prescribed fee unless it be a summons addressed to some person named in any such certificate or statement, or unless it be issued by direction of the Court or on the application of some official in the employment of the Government made by him in his official capacity.