Discovery of Remains of Human Art ivith Bones of Animals. 299 



During the rising, or at a later period, fragments of rock may 

 have accumulated at the open mouth of the lower cavern, and thus 



Fig. 2. 



have stopped up its entrance, leaving the roof, sides, and floors 

 bearing evident traces of having been an ocean cave. 



3rd Period. — Ages may have elapsed during which other strata 

 may have been depositing in other portions of our globe. But 

 ultimately the earth became inhabited by those ancient, but now 

 extinct mammalia, whose remains abound in its caverns. 



Aih Period. — Ages may again have intervened when man, in his 

 first rude state of existence, entering this deserted den through the 

 opening its former occupants had used, might have been glad to 

 shelter himself from an inclement climate in this bone-house of a 

 more ancient world. 



