Whenever defendants are named in any suit or proceeding as the unknown heirs, devisees, legatees, and assigns of any person, or are included in any class of unnamed persons, the bill of complaint or petition shall be sworn to by the moving party, his agent or attorney, and shall state that the affiant does not know and has been unable after diligent search and inquiry to ascertain the names of the persons who are included as defendants therein without being named. Upon the filing of same an order shall be entered by the circuit judge of the county in which such proceedings are pending or by a circuit court commissioner of such county, for the appearance of every defendant in such suit or proceeding who cannot, by reason of being unnamed or otherwise, be personally served with process within three months from its date. If the suit is concerning lands every publication of such order shall be followed by a description of such lands as described in the bill of complaint, and a statement that the suit involves the title to such lands or is brought to quiet the title thereto.16

12. Compiled Laws 1915, Section 12352.

13. Compiled Laws 1915, Section 12148.

14. Michigan Circuit Court Rule No. 24.

15. World Mfg. Co. v. Kent Circuit Judge, 115 Mich. 652. Chancery Rule No. 25.

16. Compiled Laws 1915, Section 12375.