“Collect on delivery.” These letters are not cabalistic, but have a determinate meaning. They import the carrier’s liability to return to the consignor either the goods or the charges. U. S. Exp. Co. v. Keef- er, 59 Ind. 207; Fleming v. Com., 130 Pa. 138, 18 Atl. G22; Express Co. v. Wolf, 79 IU. 134.