RANGE BASE OR REFUGE AREAS 33 



pabeontological remains on certain islands and the 

 presence of submerged banks in their vicinity between 

 the now disunited continental areas, undoubtedly prove. 

 No such land connections ever appear to have 

 bridged the primeval Sahara sea, and consequently the 

 links between the typical African and European faunas 

 and floras are insignificant and exclusively of recent 

 appearance. 



It now becomes necessary to revert for a time to the 

 land connections between Africa and Europe during the 

 Pleistocene Period. There can be little doubt that an 

 extension of land surface across the Mediterranean was 

 taken advantage of by birds, which seem always adverse 

 to extend their range beyond water areas. These land 

 passages across the Mediterranean have been chiefly 

 insisted upon by geologists to account for the presence 

 of the large mammalia in Europe during the Pleistocene 

 Period, and for the presence in the North-west African 

 flora of a decided European element : the Mollusca of 

 the Sahara have also, I believe, exclusively Pal^earctic 

 facies. But, as I hope ultimately to prove, these land 

 ■connections between South Europe and North-west 

 Africa were incapable of preserving from extinction the 

 large pachyderms and carnivores so characteristic of Pleis- 

 tocene time. A glance at the map will show the reason 

 for this. The area to the south of the Mediterranean 

 from which these ancient land passages led — say be- 

 tween Spain and Italy respectively — must have been 

 very restricted, confined at most within as narrow limits 

 as at the present time, and bounded by sterile deserts or 

 wide seas marking the southern limits of all the West 



European fauna and flora. Not only was the area an 



D 



