When it is necessary to make any persons defendant to a petition in the probate court filed for the partition of property or for a sale thereof because it cannot be equitably divided, and the names of all or any of such persons are unknown to the petitioner and cannot be ascertained on diligent inquiry, if the petitioner shall state in a petition, or in an affidavit thereto annexed, that the names of such persons are unknown, and that he has made diligent inquiry to ascertain the same, proceedings may be had against them without naming them; and the judge of probate must make publication as in case of nonresident defendants, describing such unknown parties as near as may be by the character in which they are sued, and with reference to their title or interest in the property sought to be partitioned or to be sold for division of the proceeds. Should petitioner, after exercising reasonable diligence be unable to locate the whereabouts, and to ascertain with certainty whether any defendant is alive at the time of the filing of the petition, the facts showing just what diligence the petitioner has exercised must be specifically alleged in the bill, and such defendant may then be made a party, by publication as in case of unknown defendants, in his name followed by the words: " ____ and his heirs or devisees, if deceased." If the defendant so named does not appear in person or by attorney before expiration of the time for filing pleadings, the court shall appoint a guardian ad litem to represent his interest. The shares or interest of such parties in the proceeds of any such sale shall be paid in the court under such directions as may be ordered by the court, and shall there be retained and paid out to the proper parties when ascertained.