274 



MAN AND THE GLACIAL PERIOD. 



Through the lowering of the main line of drainage, cav- 

 erns with a chw floor are at length left, offering shelter 

 and protection both to man and beast. Oftentimes, but 

 not always, some idea of the age of these caverns may be 

 obtained by observing the depth to which the main chan- 

 nel of drainage to which they were tributary has been 

 lowered since their formation. But to this subject also 

 we will return when we come specifically to discuss the 

 chronological question. 



The Continent. 



Systematic explorations in the caves of Belgium were 

 begun in 1833 by Dr. Schmerling, in the valley of the 

 Meuse, near his residence in Liege. The Meuse is here 

 bordered by limestone precipices 200 or more feet in 



height. Opening out 

 from these rocky walls 

 are the entrances to 

 the numerous caverns 

 which 'have rendered 

 the region so famous. 

 To get access to the 

 most important of 

 these, Dr. Schmerling 

 had to let himself 

 down over a precipice 

 by a rope tied to a 

 tree, and then to creep 

 along on all-fours through intricate channels to reach the 

 larger chambers which it was his object to explore. In the 

 cave at Engis, on the left bank of the Meuse, about eight 

 miles above Liege, he found a human skull deeply buried 

 in breccia in company with many bones of the extinct ani- 

 mals previously stated to have been associated with man 

 during the Glacial period. This so-called " Engis skull " 

 was by no means apelike in its character, but closely re- 



Fig. 79— Engis skull, reduced tafter .Lyeil.) 



