THE PLEISTOCENE OR GLACIAL PERIOD. 



505 



dwelling sites, or wherever, in the course of their use, they were lost, 

 broken, or thrown aside. In the light of this definite separation, it 



Fig. 568. — Portion of an extensive deposit of shop-refuse, near the quarry face in 

 gravel bluff, on Piny branch, near Washington, D. C, (After Holmes.) 



is not difficult to see how the similitude of two stages of art, of quite 

 different aspects and geographically dissociated, arose, and how easily 

 they might be misinterpreted. 



