PRESENT MOUTHS NOT THE ORIGINAL ONES. 
125 
kalk (Hole limestone); and it seems more nearly allied to the calca¬ 
reous portions of our green sand formation than to any other strata 
of the English series; but differs from them in aspect, in consequence 
of its containing a large admixture of magnesia, and very few organic 
remains. This district is at present for the most part cultivated, and 
without any other beasts of prey than foxes and a few wolves; but there 
appears to have been a time when its savage population was prodi¬ 
giously great, and the bones of thousands of gigantic bears, and other 
wild beasts, which once swarmed in the caverns, with which its hills are 
perforated, still remain to attest their antediluvian dominion over it. 
Though at an high elevation, this district cannot be said to be 
mountainous; its valleys indeed are flanked by precipitous crags, 
which, when seen from below, have all the ruggedness and picturesque 
form of Alpine scenery; but they are narrow, and not deep, rarely 
exceeding 300 feet, and are simply valleys of denudation, excavated by 
the diluvian waters on the surface of an elevated calcareous plain, 
which was the scene on which the bears and hyaenas that are 
entombed in the recesses of its caverns ranged unmolested by the 
approach of man. 
The entrance to the caverns at that time would have been by 
apertures on the surface of this plain, like that described as now 
existing at Scharzfeld, and of which some are found still open in the 
more elevated parts of this neighbourhood; and it seems to have 
been by these original apertures and fissures rising to the level 
surface of the main table-land, rather than by the present mouths 
in the vertical face of the cliffs, that the pebbles, and probably 
great part of the mud that occurs within the caves, found their 
