Concerning application of these terms to snow cover in high polar glaciers, a modified or qualified nomenclature may prove advisable. This is suggested by the fact that percolating melt water is not present in sufficient quantity in high polar firn to create the complicated and irregular diagenetic ice structures, and to help induce other characteristics which are more common to temperate firn. Such consideration may b est await the progress of further field research on possible differences in physical character and genesis of polar firn, which recent as yet unpublished studies have sugges ted.