After the allowance of the order and before such garnishee or officer thereof is thereby required to appear, or within a time to be specified in the order, the plaintiff may serve upon such garnishee or officer thereof written allegations and interrogatories touching any of the property liable to attachment as the property of the defendant, as provided in paragraph (3) of section 256 of this title and as to which such garnishee or officer thereof is required to give a certificate as provided in section 265 of this title.