Cfl. XIIL] . AUSTRALIAN CAVERNS. 161 



in Europe. They were not washed to the spots where the fossils now oc- 

 cur by a great flood ; but lived and died, one generation after another, in 

 the places where they lie buried. Among other arguments in favor of this 

 conclusion may be mentioned the great numbers of the shed antlers of deer 

 discovered in caves and in freshwater strata throughout England.* 



Examples also occur of fissures into which animals have fallen from 

 time to time, or have been washed in from above, together with alluvial 

 matter and fragments of rock detached by frost, forming a mass which 

 may be united into a bony breccia by stalagmitic infiltrations. Fre- 

 quently we discover a long suite of caverns connected by narrow and 

 irregular galleries, which hold a tortuous course through the interior of 

 mountains, and seem to have served as the subterranean channels of 

 springs and engulfed rivers. Many streams in the Morea are now car- 

 rying bones, pebbles, and mud into underground passages of this kind. 

 If, at some future period, the form of that country should be wholly 

 altered by subterranean movements and new valleys shaped out by 

 denudation, many portions of the former channels of these engulfed 

 streams may communicate with the surface, and become the dens of wild 

 beasts, or the recesses to which quadrupeds retreat to die. Certain caves 

 of France, Germany, and Belgium, may have passed successively through 

 these different conditions, and in their last state may have remained 

 open to the day for several tertiary periods. It is nevertheless re- 

 markable, that on the continent of Europe, as in England, the fossil 

 remains of mammalia belong almost exclusively to those of the Newer 

 Pliocene and Post-Pliocene periods, and not to the Miocene or Eocene 

 epochs, and when they are accompanied by land or river shells, these 

 agree in great part, or entirely, with recent species. 



As the preservation of the fossil bones is due to a slow and constant 

 supply of stalactite, brought into the caverns by water dropping from the 

 roof, the source and origin of this deposit has been a subject of curious 

 inquiry. The following explanation of the phenomenon has been re- 

 cently suggested by the eminent chemist Liebig. On the surface of 

 Franconia, where the limestone abounds in caverns, is a fertile soil, in 

 which vegetable matter is continually decaying. This mould or humus, 

 being acted on by moisture and air, evolves carbonic acid which is dis- 

 solved by rain. The rain-water, thus impregnated, permeates the porous 

 limestone, dissolves a portion of it, and afterwards, when the excess of 

 carbonic acid evaporates in the caverns, parts with the calcareous matter, 

 and forms stalactite. Such facts seem to imply that the date of the emer- 

 gence of the district was very modern, for stalactite could not begin to form 

 until the emergence of the cavernous rock, and the land shells and land 

 animals are usually imbedded in the lowest part of the stalactite deposit. 



Australian cave-breccias. — Ossiferous breccias are not confined to Eu- 

 rope, but occur in all parts of the globe ; and those lately discovered in 

 fissures and caverns in Australia correspond closely in character with 

 what has been called the bony breccia of the Mediterranean, in which the 



* Owen, Brit. Foss. Mam. xxvi. and Buckland, Rel. Dil. 19, 24. 

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