Fig. 11. Formation of the typical limestone cavern. After Gaudry.
V. Vertical section of limestone cliff showing (S) waters percolating from above; (A-O) interior of the cavern; and (G) grotto entrance, original exit of the cavern waters. H. Horizontal section of the same cavern showing the (G) grotto entrance and (A, G, O, B) the ramifications of the cavern.
It would appear that the majority of the caverns were formed in pluvial periods of early glacial times; the formation had been completed, the subterranean streams had ceased to flow, and the interiors were relatively dry and free from moisture in Fourth Glacial and Postglacial times, when man first entered them. There is no evidence, however, that the cavern depths were generally inhabited, for the obvious reason that there was no exit for the smoke; the old hearths are invariably found close to or outside of the entrance, the only exception being in the entrance to the great cavern of Gargas, where there is a natural chimney for the exit of smoke. There was no cave life, strictly speaking—it was grotto life; the deep caves and caverns were probably penetrated only by artists and possibly also by magicians or priests. It is in the abris or shelters in front of the grottos and in the floors of the caverns that remarkable prehistoric records are found from late Acheulean times to the very close of the Palæolithic, as in the wonderful grotto in front of the cave at Castillo, near Santander. Thus, as Obermaier[(60)] observes: "In Chellean times primitive man was a care-free hunter wandering as he chose in the mild and pleasant weather, and even the colder climate of the arid 'loess' period of the late Acheulean was not sufficient to overcome his love of the open; he still made his camp on the plains at the edge of the forest, or in the shelter of some overhanging cliff." Only in rare instances, as at Castillo, were the Acheulean hearths brought within the entrance line of the grotto.
DIFFERENCES OF OPINION AS TO THE GEOLOGIC AGE OF THE PALÆOLITHIC CULTURE STAGES
The right-hand column represents the theory adopted in this volume.
| Geologic Time | Penck, 1910 Geikie, 1914 | Wiegers, 1913 | Boule, Breuil, Obermaier, 1912 Schmidt, 1912 |
| Postglacial. | Magdalenian. | Bronze. Neolithic. Azilian. | Magdalenian. Solutrean. Aurignacian. |
| IV. Glacial. | Solutrean. | Magdalenian. Solutrean. Aurignacian. Mousterian. | Mousterian. |
| Third Interglacial. | Mousterian. | Mousterian. | Early Mousterian. Cold Acheulean. Warm " Chellean. Pre-Chellean. |
| III. Glacial. | Mousterian. | Cold Acheulean. | |
| Second Interglacial. | Acheulean. Chellean. | Warm Acheulean. Chellean. | |
| II. Glacial. | Pre-Chellean. | ||
| First Interglacial. |
Interpretation of these four kinds of evidence as to the antiquity of human culture in western Europe still leads to widely diverse opinions. On the one hand, we have the high authority of Penck[(61)] and Geikie[(62)] that the Chellean and Acheulean cultures are as ancient as the second long warm interglacial period. An extreme exponent of the same theory is Wiegers,[(63)] who would carry the Pre-Chellean back even into First Interglacial times. On the other side, Boule,[(64)] Schuchardt,[(65)] Obermaier,[(66)] Schmidt,[(67)] and the majority of the French archæologists place the beginning of the Pre-Chellean culture in Third Interglacial times.
In favor of the latter theory is the strikingly close succession of the Lower Palæolithic cultures in the valley of the Somme, followed by an equally close succession from Acheulean to Magdalenian times, as, for example, in the station of Castillo. It does not appear possible that a vast interval of time, such as that of the third glaciation, separated the Chellean from the Mousterian culture.
On the other hand, in favor of the greater antiquity of the Pre-Chellean and Chellean cultures may be urged their alleged association in several localities with very primitive mammals of early Pleistocene type, namely, the Etruscan rhinoceros, Steno's horse, and the saber-tooth tiger, as witnessed in Spain and in the deposits of the Champs de Mars, at Abbeville.
It is true, moreover, that at points distant from the great ice-fields, like the valley of the Somme and that of the Marne, we have no other means of separating glacial from interglacial times than that afforded by the deposition and erosion of the 'terraces'; in fact, the interpretation of the age of the cultures may be similar to that applied to the age of the mammalian fauna. There are no proofs of periods of severe cold in western Europe in any country remote from the glaciers until the very cold steppe-tundra climate immediately preceding the fourth glaciation swept the entire land and drove out the last of the African-Asiatic mammals.