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QQ THE CANADIAN NATURALIST. [Vol. X. 



sheep. A flint flake discovered by the Rev. Osmund Fisher, at 

 Crayford, and a second discovered by Messrs. Cheadle and Wood- 

 ward, at Erith, prove that man was present in the valley of the 

 Thames at this time; while the more recent discoveries of Mr. 

 Flaxmau Spurrell indicate the very spots where the palgeolithic 

 hunter made his implements, and prove that he used implements 

 of the River-drift type, so widely distributed over tlie surface o: 

 the earth. The arctic animals at this time were present, but 

 noi in full force, in Southern Britain, and the innumerable rein- 

 deer which characterise the later deposits of the Pleistocene age 

 had not, so far as we know, taken possession of the valley of the 

 Thames. 



To what stage in the Pleistocene period are we to refer these 

 traces of the River-drift hunter ? The only answer which I am 

 able to give is that the associated animals are intermediate be- 

 tween the Forest-bed group and that which characterises the 

 late Pleistocene division in the region extending from the Alps 

 and the Pyrenees as far north as Yorkshire. Nor am I able to 

 form an opinion about their relation to the submergence of 

 Middle or Northern Britain under the waves of the alacial sea. 

 They are quite as likely to be pre- as post glacial, 



THE RELATIONS OP THE RIVER-DRIFT HUNTER OF THE LATE 

 PLEISTOCENE TO THE GLACIAL SUBMERGENCE. 



The rudely chipped implements of the River-drift hunter lie 

 scattered through the late Pleistocene river deposits in Southern 

 and Eastern England in enormous abundance, and as a rule in 

 association with the remains of auimals of arctic and of warm 

 habit, as well as some or other of the extinct species of reindeer 

 and hippopotamus, along with mammoth and wooly rhinoceros. 

 What is their relation to the submergence of the land and the 

 lowness of the temperature, which combined together have 

 resulted in the local phenomena known as glacial and inter- 

 «;lacial ? 



The geographical change in Northern Europe at the close of 

 the Forest-bed age was very great. The forest of the North Sea 

 sank beneath the waves", and Britain was depressed to a depth of 

 no less than 2,300 feet in the Welsh mountains, and was reduced 

 to an archipelago of islands, composed of what are now the higher 

 lands. The area of the English Channel also was depressed, and 

 the "silver streak" was somewhat wider than it is now, as is 



