32 PliELIMINARY INQUIRIES. 



in America, nor, perhaps, the general mass of glaciers run into the Mediterranean Sea, wo shall 

 find, if we inquire a little, that it was in a still worse case than North America. The latter had 

 an outlet ; but we shall presently see that Europe had none. 



Let the reader figure on a map the extent of the land in Europe covered by the glacial ice 

 ("shown in Map 4). Then let him lay down its tertiary and quaternary beds (shown in Map 3). 

 They, of course, represent at least some of the water previous to that period — they are the site 

 of the seas in which these beds were deposited. Next, let him remember that at that epoch 

 itself the general level of Europe and Asia was considerably lower than it is now. The Sahara 

 was united with the Mediterranean and the Black Sea, and the Black Sea with the Caspian.* 



Sir Roderick Murchison and M. de Verneuil consider that another sea as large as the Mediter- 

 ranean, and several hundred feet in depth, existed about the south of the Caspian during the 

 pliocene epoch (that is, the commencement of the glacial epoch), f It is, therefore, no very imrea- 

 sonable surmise that the level of Europe fi-om the longitude of the western termination of the 

 Sahara to the longitude of the Caspian Sea, was 100 fathoms lower than it is now. If the reader 

 will add from Map 2 the portions of Europe, which in that case would be under water, to the other 

 two (the limits of glacial action and tertiary deposits), he will find that Europe has but all disap- 

 peared. In addition to this, however, the sandy plains in the centre of Germany stretching with 

 interruptions from the Danube to the Baltic, show every appearance of having been recently 

 under water. If we reckon them also as submerged at that epoch, then Europe, east of the Atlantic, 

 will be practically almost blotted out from the map. 



If that be so (as so it seems to be), scarcely any life at all can have survived the glacial epoch 

 in Europe. Whether at that time the communication with Asia was also cut ofi' is doubtfid, 

 but is not of much consequence, as a communication after the glacial epoch was certainlj' opened 

 between them. Still, to complete our knowledge of the state of facts during the miocene epoch, we 

 may note, regarding the then boundaries of Europe, that we are sure that it was absolutely cut off 

 on the south by the Sahara, on the south-east by sea, which then covered Arabia and Persia, and 

 by the Aralo-Caspian seas above-mentioned ; and the interesting fact to which we shall presently 

 come, that seals of the same species as those now living in the Arctic Seas, occur both in the 

 Caspian and Lake Baikal, renders it almost certain that a commimication existed between the 

 Caspian and the Arctic Seas ; so that Europe, previous to the glacial epooh, was probably a 

 group of islands isolated from Asia, and from Africa — whether or not from America we shall 

 presently see. 



* " I was particularly struck by the fact, that several given by Sir Roderick Murchison and M. de Verneuil to 



of my fossil shells from the Sahara, in the superficial de- the limestone and associated sandy beds, of brackish 



posit, proved specifically identical with fresh-water ter- water origin, which have been traced over a very ex- 



tiary fossils given me by my friend, Captain Spratt, and tensive area, surrounding the Caspian Azof and Aral Seas, 



obtained by him in the fresh-water deposits of the Black and parts of the northern and western coasts of the Black 



Sea." — Tristram's Sahara, p. 370. Sea. The limestone rises occasionally to the height of 



" M. Eschcr von dur Luith himself, together with several hundred feet above the sea, and is supposed to 



MM. Desor and Martins, have found marine shells, espe- indicate the former existence of a vast inland sheet of 



cially the common Cockle, Condium Edule, scattered far brackish water, as large as the Mediterranean, or larger." 

 and wide, from west to east, over the desert (Sahara) ; " The proportion of recent species, agreeing with the 



while the shells of these, and other living species, have fauna of the Caspian, is so considerable, as to leave no 



also been found in boring Artesian wells, at the depth of doubt in the minds of the geologists above cited, that this 



many feet below the surface." — Ltell's Elements of Geo- rock, also called by them the ' Steppe Limestone,' belongs 



logy, 6th edit. 186.5, p. 175. to the phocene period." — Lyell, op. cit. p. 209. 



\ " Aralo-Caspian formations. — This name has been 



