Michigan Compiled Laws, Chapter 600. Revised Judicature Act of 1961 § 600.1341

Sec. 1341. The chief judge of a court may order additional jurors selected by the board for service during the period of service of a jury panel or a part of a panel. A judge of a court of record may order additional jurors selected by the board for immediate service in a particular case. The order shall specify the number to be selected and the time and place of selection. If additional jurors are needed for immediate service in a particular case, any member of the jury board may conduct the selection if witnessed by the clerk or the clerk's deputy and by the judge ordering the selection. Jurors whose names are so selected shall be given notice to attend court in the manner that the court directs. Additional jurors so selected shall become members of the panel then serving unless otherwise directed by the chief judge.