PLEISTOCENE OF EUROPE, NORTH AFRICA, AND NORTH AMERICA 491 



with horse and mammoth remains in regions which are now barren tundras 

 with frozen subsoil. The preservation of the flesh and hair of the mam- 

 moth found at Elephant Point was not due originally to freezing, l3ut to 

 burial in soft mud which protected the parts from bacterial decay; the 

 parts of the body above the surface were rotted away. There is some evi- 

 dence that these mud deposits were due to river flood-plain action and that 



Fig. 216. — Bluff on the south side of Eschscholtz Bay, .Alaska, where remains of many 

 Pleistocene mammals have been found (' big bone beach '). The cross indicates the spot where 

 part of a mammoth skeleton with some skin and hair was discovered. After Quackenbush, 

 American Museum Expedition, 1908. 



a part of the deposits have since become frozen. All are now covered by 

 the thick vegetation of the tundras except where exposed at the seashore 

 and along river borders. 



The contemporaneity of these Alaskan species is by no means demon- 

 strated. They may represent several successive periods of Pleistocene 

 time: the moose and reindeer in the forests, the horses and bison (typical 

 grazers) grazing on the uplands, the elephants and rare mastodons grazing 

 and browsing in the forest borders, the beaver building their dams from the 

 forests along the streams. The musk oxen and caribou, adapted to the 

 mosses and shrubs of the barren grounds, are indicative of different 

 periods. 



Certainly the horse, the bison, and the elephants would have been 



