Whenever any initiative or referendum petition has been filed with the secretary of state, he shall forthwith separate the part-petitions by counties and transmit such part-petitions to the boards of elections in the respective counties. The several boards shall proceed at once to ascertain whether each part-petition is properly verified, and whether the names on each part-petition are on the registration lists of such county, or whether the persons whose names appear on each part-petition are eligible to vote in such county, and to determine any repetition or duplication of signatures, the number of illegal signatures, and the omission of any necessary details required by law. The boards shall make note opposite such signatures and submit a report to the secretary of state indicating the sufficiency or insufficiency of such signatures and indicating whether or not each part-petition is properly verified, eliminating, for the purpose of such report, all signatures on any part-petition that are not properly verified.
In determining the sufficiency of such a petition, only the signatures of those persons shall be counted who are electors at the time the boards examine the petition.