Part 6 (1/2)

This _patina_ (to use the established term) is the proof of their long-continued repose in the beds, and is, so to speak, the stamp of their antiquity.

CHAPTER III.

The Man of the Great Bear and Mammoth Epoch lived in Caverns--Bone Caverns in the Quaternary Rock during the Great Bear and Mammoth Epoch--Mode of Formation of these Caverns--Their Division into several Cla.s.ses--Implements of Flint, Bone, and Reindeer-horn found in these Caverns--The Burial-place at Aurignac--Its probable Age--Customs which it reveals--Funeral Banquets during the Great Bear and Mammoth Epoch.

Having given a description of the weapons and working implements of the men belonging to the great bear and mammoth epoch, we must now proceed to speak of the habitations.

Caverns hollowed out in the depth of the rocks formed the first dwellings of man. We must, therefore, devote some degree of attention to the simple and wild retreats of our forefathers. As the objects which have been found in these caverns are both numerous and varied in their character, they not only throw a vivid light on the manners and customs of primitive man, but also decisively prove the fact of his being contemporary with mammals of species now extinct, such as the mammoth, the great bear, and the _Rhinoceros tichorhinus_.

But before proceeding any further, it is necessary to inquire in what way these caverns could have been formed, in which we find acc.u.mulated so many relics of the existence of primitive man.

M. Desnoyers, Librarian of the Museum of Natural History at Paris, is of opinion that these caverns are crevices of the same cla.s.s as metalliferous _lodes_, only instead of containing metallic ores they must have been originally filled by the deposits of certain thermal springs.

[Ill.u.s.tration: Fig. 19.--Theoretical Section of a Vein of Clay in the Carboniferous Limestone, _before_ the hollowing out of Valleys by diluvial Waters.]

Fig. 19 represents, according to M. Desnoyers' treatise on _caverns_, one of these primordial veins in the carboniferous limestone. At the time of the diluvial inundation, these veins were opened by the impetuous action of the water. When thus cleared out and brought to the light of day, they a.s.sumed the aspect of caves, as represented in fig.

20.

[Ill.u.s.tration: Fig. 20.--Theoretical section of the same Vein of Clay converted into a Cavern, _after_ the hollowing out of Valleys by diluvial Waters.]

The European diluvial inundation was, as we know, posterior to the glacial epoch.

It is also likely that caverns were sometimes produced by the falling in of portions of some of the interior strata, or that they were formerly the natural and subterranean channels of certain watercourses; many instances of this kind being now known in different countries.

We must also add that it is not probable that all caverns originated in the same way; but that one or other of the several causes just enumerated must have contributed to their formation.

Under the general denomination of _caverns_, all kinds of subterranean cavities are comprehended; but it will be as well to introduce several distinctions in this respect. There are, in the first place, simple clefts or crevices, which are only narrow pits deviating but slightly from the vertical. Next we have grottos (or _baumes_ as they are called in the south of France), which generally have a widely opening inlet, and are but of small extent. Lastly, we must draw a distinction between these and the real bone caverns, which consist of a series of chambers, separated by extremely narrow pa.s.sages, and are often of very considerable dimensions. Some of these caverns occupy an extent of several leagues underground, with variations of level which render their exploration very difficult. They are generally very inaccessible, and it is almost always necessary to ply the pick-axe in order to clear a way from one chamber to another.

In most of these grottos and caverns the ground and sides are covered with calcareous deposits, known by the name of _stalact.i.te_ and _stalagmite_, which sometimes meet one another, forming columns and pillars which confer on some of these subterranean halls an elegance replete with a kind of mysterious charm.

These deposits are caused by the infiltrated water charged with carbonate of lime, which, oozing drop by drop through the interstices of the rock, slowly discharge the carbonic acid which held the carbonate of lime in solution, and the salts gradually precipitating form the crystalline or amorphous deposits which const.i.tute these natural columns.

The calcareous deposits which spread over the ground of the caverns are called _stalagmite_, and the name of _stalact.i.te_ is given to those which hang down from the roof, forming pendants, natural decorations, and ornaments as of alabaster or marble, producing sometimes the most magnificent effects.

Under the stalagmite the largest number of animal bones have been found.

This crust, which has been to them a preservatory grave, is so thick and hard that a pick-axe is required in order to break it. Thanks to the protecting cover, the bones have been sheltered from all the various causes of decomposition and destruction. The limestone formed a kind of cement which, uniting clay, mud, sand, flints, bones of men and animals, weapons and utensils into a compact ma.s.s, has preserved them for the study and consideration of scientific men in our own days.

The soil called _bone-earth_ is, in fact, found under the crystalline bed which covers the ground of the caverns.

Fig. 21, which represents a section of the cave of Galeinreuth, in Bavaria, will enable us clearly to understand the position occupied by the bones in most of these caverns.

[Ill.u.s.tration: Fig. 21.--The Cave of Galeinreuth, in Bavaria.]

Bone-earth consists of a reddish or yellowish clay, often mixed with pebbles, which seem to have come from some distant beds, for they cannot be attributed to the adjacent rocks. This stratum varies considerably in depth; in some spots it is very thin, in others it rises almost to the top of the cavern, to a height of forty or fifty feet. But in this case it is, in reality, composed of several strata belonging to different ages, and explorers ought to note with much attention the exact depth of any of the organic remains found in their ma.s.s.

There are, however, in several bone-caverns certain peculiarities which demand a special explanation. Caves often contain large heaps of bones, situated at heights which it would have been absolutely inaccessible to the animals which lived in these places. How, then, was it possible that these bones could have found their way to such an elevated position? It is also a very strange fact, that no cavern has ever produced an entire skeleton or even a whole limb of the skeleton of a man, and scarcely of any animal whatever. The bones, in fact, not only lie in confusion and utter disorder, but, up to the present time, it has been impossible to find all the bones which in times past formed an individual. It must, therefore, be admitted, that the acc.u.mulation of bones and human remains in most of the caves are owing to other causes than the residence of man and wild animals in these dark retreats.