_AZILIAN._--Industry of the surviving Crô-Magnon and other resident races, and of newly arrived brachycephalic and dolichocephalic races in western Europe; decadent forms of flint and bone workmanship; entire absence of art. _Daun_ stage of Postglacial retreat; Europe with a milder climate and forest and meadow fauna like that of early historic times. _MAGDALENIAN._--Closing stage of the industry and art of the Crô-Magnon race; bone implements highly developed; marked decline in the flint industry. Close of Postglacial Period; climate alternately cold and moist (corresponding with the _Bühl_ and _Gschnitz_ Postglacial advances of the ice in the Alpine region), or cold and arid; Europe covered with the tundra and steppe fauna; life chiefly in the shelters and grottos. _SOLUTREAN._--Culminating stage of flint industry; apparent invasion in eastern Europe of the Brünn (Brüx, Předmost, and [?] Galley Hill) race. The highly developed flint industry of the Solutrean types; art development of the Crô-Magnon race partly suspended. Dry, cold climate; life largely in the open. _AURIGNACIAN._--Appearance of the Crô-Magnon race in southwestern Europe, succeeding the Mousterian industry; art of engraving and drawing and sculpture of human and animal forms developing. Animal life the same as during the fourth glaciation; climate cold and increasingly dry; life chiefly in the grottos and shelters. The successive phases of development of Upper Palæolithic industry and art have been traced with extraordinary precision in Dordogne, in the Pyrenees, in northern Spain, and along the Danube and upper Rhine by a host of able workers--Cartailhac, Capitan, Peyrony, Bouyssonnie, Lalanne, and others. Breuil has made himself master especially of the Aurignacian and has succeeded Piette as the great historian of Upper Palæolithic art. Obermaier's chief service has been the comparison of the Upper Palæolithic of the Danubian region with that of the Dordogne and northern Spain both in regard to the geologic age and the archæologic and racial succession. The labors of Schmidt along the upper Rhine and Danube have not only brought this region into definite prehistoric relation with the Dordogne and the Pyrenees but have given us by far the clearest evidence of the relation between the human and the industrial development and the succession of climatic phases in northern Europe. Finally, the explorations of Commont along the River Somme have proved that this region, too, was frequented throughout all Upper Palæolithic times, during which it exhibits an industrial development hardly less important than that of the Lower Palæolithic.