Dr J. W. Dawson on the Antiquity of Man. 49 



" 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, considera- 

 tions of the time required to allow of many species of car- 

 nivorous 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 under- 

 ground 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 pre- 

 sent 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 pre- 

 sent system of drainage came into play, or before the exist- 

 ing valleys were scooped out. Other signs of subsequent 

 fluctuations are afi'orded by gravel containing elephants' 

 bones at slight elevations above the Meuse and several of its 

 tributaries. The loess also, in the suburbs and neighbour- 

 hood of Liege, occurring at various heights in patches lying at 

 between 20 and 200 feet above the river, cannot be explained 

 without supposing the filling up and re-excavation of the 

 valleys at a period posterior to the washing in of the animal 

 remains into most of the old caverns. It may be objected 

 that, according to the present rate of change, no lapse of 

 ages would sufiice to bring about such revolutions in physical 

 geography as we are here contemplating. This may be true. 

 It is more than probable that the rate of change was once 

 far more active than it is now. Some of the nearest vol- 

 canoes, namely, those of the Lower Eifel about sixty miles 



NEW SERIES. VOL. XIX. NO. I. JANUARY" 1864. G 



