Page:A Treatise on Geology, volume 1.djvu/327

 CHAP. VI. floors, stalactitical canopies, and other signs, there is no room to doubt that in all the ossiferous and common caves the solvent and mechanical powers of water have been exerted in modifying the size and form of the cavities. Inspection of the sea coast demonstrates how, at this day, the wasting and undermining agency of water forms caves very similar, in general character, to those containing fossil bones. In some cases (Kirkdale, Rabenstein in Franconia), it appears probable that the existing valley has been deepened since the time when the cave was tenanted by wild animals, because the mouth of the cave opens on a steep breast of rock several yards above the bed of the valley. Let us admit, then, as sufficiently proved, the existence of open caves and fissures in limestone rocks, at the time when elephants, tigers, hyænas, rhinoceroses, &c. lived in Europe; and inquire further how it happened that their bones came to be entombed in the dark chambers of the rocks.

1. Into open fissures they might fall alive, or be drifted by inundations when dead. It seems difficult to account otherwise for the nearly entire skeleton of a rhinoceros found enveloped in mud and pebbles in the Dream Cavern, near Wirksworth, described by Dr. Buckland (Reliq. Diluv.). Some such mode of explanation must be resorted to for explanation of the accumulation of bones in Banwell Cave, Hutton Hole, and other singular fissures in the Mendip hills. The osseous breccia, as it is called (a mixture of red loam, pieces of stone, and bones), which fills fissures of the calcareous rocks on the Mediterranean coast of Aragon, France (Antibes), Italy (Nice, Pisa), Corsica, Sardinia, &c., appears to have been introduced by currents of water; and from the occurrence of land shells and marine shells and zoophyta in some of these repositories (Villefranche), it is clear that both freshwater inundations, and overflowing of the sea, have influenced the results. The probability seems to be, that the land has there experienced changes of level: in some cases (Palermo) the bones are thought to have been deposited in the sea near