CHAPTEE V. 



PAST GEOGRAPHY OF THE GLOBE Continued GLACIAL EPOCH. 



Such a Miocene Atlantis as that above defined sufficiently explains the common distribution of 

 plants and animals in Europe and Ajnerica, up to the glacial epoch. We have now to consider how 

 and by what channels the rehabilitation and distribution of these lands themselves were effected 

 subsequent to that period. I have rather anticipated this in regard to Greenland, Iceland, and 

 Spitzbergen. But the main question of the restoration of life to Europe and America still remains. 



Life in North America being by the glacial eold driven into Mexico, and in Europe almost 

 entirely extirpated, and the communication with North America cut olT, except at an extreme point 

 which lay at the greatest distance from the siu'vi\Tng focus of life in each country respectively, 

 viz. as regards America in the extreme north-east, while all the survi\-ing life was crowded into the 

 extreme south-west ; and as regards Europe in the extreme north-west, while the nearest point 

 whence life could be drawn was probably the south-east of Asia ; it is plain that neither of the 

 continents could help the other, America covdd receive European colonists, and Europe American, 

 only after they had each been re-peopled from some other source. 



In the first place, as to Europe, it is plain that it must have drawn its new inhabitants almost 

 entirely from Asia ; the Sahara still subsisted as a sea, although perhaps diminished in size, and cut 

 it off from Africa ; and accordingly no trace of the fauna or flora of Africa proper is to be found in 

 Exirope.* There was, therefore, no place except Asia on which it could draw (any slight remnants of 

 the miocene flora which are still to be foimd in Europe were doubtless preserved in those parts of 

 the South of Europe which existed as islands beyond the reach of the ice of the glacial epoch ;) and, 

 in accordance with this, we find that the flora and faima of Europe and Asia are essentially the 

 same. It is to be expected that in such an immense tract of country climatal variations must have 

 arisen since then ; and we can distinguish three sub-provinces (which may be called respectively the 

 Scandinavian, the Mediterranean, and the East, or Mongolo- Siberian), but essentially the whole of 

 Asia north of the line of the Himmalayahs and Europe is of one type. When we come to trace the 

 spread of particular species of plants and animals, I have been surprised to find how happily 

 this view explains many seeming anomalies, which have puzzled naturalists to account for, such 

 as the distribution of the cedars — the silver firs— many of the mammals, and in fact of every class 

 of organic life in Europe and Northern Asia. 



As to America the whole of its pre-existing flora and fauna having been crowded into the north- 

 west of Mexico and Central America, that is the source from which it must have been restored. On 

 the retreat of the ice the flora, of course, would follow it step by step, but its starting-point being 

 west of the dividing ridge or backbone of America, or, what is probably more to the purpose, west 

 of the tertiary sea which lay in the line of the Missouri and Mackenzie Eivcrs, and thus being 

 penned in between the Pacific and these barriers, it would flow iip in strength into Cali- 



* Any instances, such as the lion or leopard, which pearancc. See remarks on the distribution of the lion 

 seem inconsistent with this statement, are only so in ap- postca. 



