248 SPARKS FROM A GEOLOGIST'S HAMMER. 



forests of England and Central Europe before the chase 

 of the human hunter?" To answer these questions we 

 must ascertain the remoteness of the epochs of continental 

 glaciation, and of the disappearance of the continental 

 glaciers. These are unsolved problems in science. If 

 continental glaciation was caused by a state of maximum 

 eccentricity in the earth's orbit, as Mr. Croll maintains, 

 the last secular midwinter probably occurred about 80,000 

 years ago, and the Siberian carcasses have lain preserved 

 for eighty or a hundred thousand years; and the decline 

 of the glaciers which witnessed the presence of (Mongol- 

 oid?) man in Europe was probably not later than 50,000 

 years ago.* If continental glaciation was caused by the 

 precession of the equinoxes, as M. Adhemar contends, the 

 last geological midwinter may have been about 10,500 

 years ago, and the pluvial condition of Europe was some- 

 what less remote. Regardless of these theories, the pres- 

 ent writer is of the opinion that the geological events 

 which have taken place since the epoch of general glacia- 

 tion do not demand over ten thousand years ; and he 

 inclines to think that the pluvial epoch of Western Europe 

 may correspond with those cataclysms of Europe and 

 Western Asia known as the deluges of Ogyges, Deucalion, 

 Noah, and perhaps of the Great Yu in China, f 



Only two species of elephants have survived to our 

 day. These are the African and the Indian (Elephas 

 Africanus and Elephas Indiciis). The former is distin- 

 guished by the rounded skull, the immense ears and the 

 lozenge-shaped figure presented by the outcropping plates 



* An exposition of CroH's glacial theory will be found in chapter vii, p. 186. 

 t See more particularly in chapter vi, p. 158 seq. 



