IX.] LAND CHANGES. 337 



are clear indications of a Central Asiatic sub-region as far back 

 as the Plistocene epoch. 



The foregoing brief survey of the Plistocene mammals of the 

 eastern division of the Holarctic region enables 

 certain deductions to be drawn as to geographical 

 changes which have taken place in the area since the Plistocene - 

 that epoch. 



In the first place, the occurrence of remains of the tiger in the 

 New Siberian, or Liakov Islands, lying far within the Arctic 

 Circle, indicates the union of those islands with the Siberian main- 

 land ; and this greater extension of the land at the north-eastern 

 extremity of Asia would naturally lead to the conclusion that there 

 was also a land-connection with Alaska across Bering Strait. 

 That such was really the case is proved by the discovery during 

 the voyage of H. M. S. " Blossom," in the years 1825-28, of 

 remains of the horse, mammoth, and bison, in the frozen soil of 

 Eschscholtz Bay, Kotzebue Sound, Alaska 1 ; this evidence being 

 confirmed by the occurrence of the musk-ox in the European 

 Plistocene, as it is also by the number of species of mammals still 

 common to the more northern parts of the two hemispheres. And 

 here it may be mentioned that, according to the researches of the 

 Russian geologists, Siberia, instead of being covered like northern 

 Europe with a continuous ice -sheet during the glacial epoch, 

 had only a number of comparatively small glaciers, so that the pre- 

 glacial fauna was able to exist here at a time that it could not live 

 in Europe. Still the frozen condition of the subsoil, and the 

 formation of ground-ice in the rivers, rendered the preservation of 

 the carcases of mammoths, rhinoceroses, bison, and musk-oxen an 

 easy matter. 



Passing to south-western Europe, the occurrence of remains of 

 the African elephant in Sicily and Spain, together with the 

 presence of small allied species in the Plistocene of Malta, and 

 likewise of remains of the Barbary sheep and Barbary ape in 

 southern Europe, indicates a free land-communication between 

 Europe and Africa, both by way of the Straits of Gibraltar, and 

 likewise between Italy, Sicily, and Tunis; Malta being then also in 



1 Beechey's Voyage to the Pacific and Behring's Straits in H.M.S. 

 "Blossom," Vol. II. 



L. 22 



