[Illustration: FIG. 101. Entrance to the grotto of Sirgenstein. After R. R. Schmidt. "Of all the stations along the Danube by far the most important is that of Sirgenstein ... which was first occupied by the Neanderthals in early Mousterian times and continued to be visited by the Lower and Upper Palæolithic men until the very close of the Upper Palæolithic."] Of all the stations along the Danube, by far the most important is that of Sirgenstein, lying between the modern cities of Nuremberg and Augsburg, which was first occupied by the Neanderthals in early Mousterian times and continued to be visited by the Lower and Upper Palæolithic men until the very close of the Upper Palæolithic. The continuous section of animal life and of human culture which this remarkable cavern yields afforded Schmidt,(20) who began his researches here in the spring of 1906, a key to the prehistory of all the eighteen caverns in the region of the upper Danube and upper Rhine. In Sirgenstein the primitive Mousterian culture of the early Neanderthals was found, together with remains of the mammoth, bison, reindeer, a species of wild horse, and the cave-bear; this Mousterian industry closed with a record of the arrival in this region of the Obi lemming from northern Russia. Later on the Crô-Magnon race of Aurignacian times left on the floor of the cavern remains of their flint industry and of their feasts, including the bones of the woolly rhinoceros, mammoth, stag, and reindeer. During Upper Palæolithic Solutrean times the cavern was not occupied; but early in Magdalenian times it was again inhabited by man, and coincident with his return is the arrival of a great migration of the banded lemming (_Myodes torquatus_) from the arctic tundras of the north. Finally, toward the end of the Upper Palæolithic, in late Magdalenian times, another climatic transition is indicated by the appearance of the pika, or tailless hare (_Lagomys pusillus_). During the Bronze Age this favorite grotto was again entered, and it was also inhabited during a portion of the Iron Age. The débris of these various cultures, hearths, and deposits of cave loam reach a total thickness of 8-1/2 feet and mark Sirgenstein as first in rank among the Palæolithic stations of Germany. TYPES AND MIGRATIONS OF THE MAMMALS HUNTED BY THE NEANDERTHALS