The presence of bones in the clayey mud of the floor of the Adelsberg cave accords well with this hypothesis; but the case is different with those which I found in the heaps of limestone blocks and clayey mud. The bones are not at the surface of the heap, but rather towards its middle part, buried among the blocks, and crushed by them. From this position, and the height at which the skeleton mentioned above occurs from the floor of the cave, it cannot be supposed that it formed part of the bones with which the bottom of the cave is strewed, nor that the blocks had fallen upon it. The bones contained in the heap in question must have been brought into their present position at the same time, and by the same cause as the limestone blocks. They could not, therefore, have belonged to animals which inhabited these caves, and died there peaceably. If it be remarked, that these blocks, which are sometimes very large, heaped up above one another, and mixed with clayey mud, have their angles perfectly fresh, and are of the same nature as the limestone of the walls of the cave, it cannot be admitted that they have been brought from a distance. This mode of arrangement could only have been produced by their falling from the roof of the cave. The following facts also give support to this opinion. In the cave of Gaylenreuth, a fissure of the third grotto, was the means, in 1784, of disclosing a new one, fifteen feet long and four broad, where the greatest quantity of hyena or lion bones were found. _The aperture was much too small for these animals to have passed through it._ In a cave discovered in 1824, in the district of Lanark in Upper Canada, Mr Bigsby observed, that the floor was covered with debris of brown granular limestone, similar to that of the walls, and that the bones especially formed a heap there. He thinks that the animal, whose bones have been found in this cave, was much too large to have got into it alive or entire.--_Silliman’s Journal, June 1825_, p. 354. It must therefore be also admitted here, either that the bones could only have got into the cave in the same manner as the heaps of blocks found in the Adelsberg cave; that is to say, by falling from the roof, or that the apertures have been closed since the period at which the animals were buried. If it be now considered, _1st_, That the surface of the secondary limestone mountains of Carniola is covered with a layer of reddish clay; and, _2dly_, That the clayey mud of the heap in the Adelsberg cave is mineralogically the same as that which forms the floor of the cave; may it not be supposed, that the same catastrophe which produced the heaps in the cave may have, at the same time, introduced into it the reddish clayey mud of the surface, which, by extending itself over the floor of the cave, would have contributed to cover the bones that were lying there?