CHAP. iv. ANTIQUITY OF Llf GE CAVE-BONES. 73 



the bones of animals which may be carried away during 

 floods. 



The manner in which some of the large thigh and shank 

 bones of the rhinoceros and other pachyderms are rounded, 

 while some of the smaller bones of the same creatures, and 

 of the hysena, bear, and horse, are reduced to pebbles, shows 

 that they were often transported for some distance in the 

 channels of torrents, before they found a resting-place. 



When we desire to reason or speculate on the probable 

 antiquity of human bones found fossil in such situations as 

 the caverns near Liege, there are two classes of evidence to 

 which we may appeal for our guidance. First, considerations 

 of the time required to allow of many species of carnivorous 

 and herbivorous animals, which flourished in the cave period, 

 becoming first scarce, and then so entirely extinct as we 

 have seen that they had become before the era of the Danish 

 peat and Swiss lake dwellings : secondly, the great number 

 of centuries necessary for the conversion of the physical 

 geography of the Liege district from its ancient to its present 

 configuration ; so many old underground channels, through 

 which brooks and rivers flowed in the cave period, being now 

 laid dry and choked up. 



The great alterations which have taken place in the shape 

 of the valley of the Meuse and some of its tributaries 

 are often demonstrated by the abrupt manner in which the 

 mouths of fossiliferous caverns open in the face of perpen 

 dicular precipices 200 feet or more in height above the 

 present streams. There appears also, in many cases, to be 

 such a correspondence in the openings of caverns on opposite 

 sides of some of the valleys, both large and small, as to 

 incline one to suspect that they originally belonged to a 

 series of tunnels and galleries which were continuous before 

 the present system of drainage came into play, or before the 

 existing valleys were scooped out. Other signs of subsequent 



