FORMER LAND CONNECTIONS. 139 



••some explanation. In order to meet the needs of botanists such as 

 Hooker and Engler, who have pointed out certain strong floral 

 resemblances between the two continents, the reasonable assump- 

 tion can be made that the gap, though wide enough to prevent 

 animal migration on the whole, was for a time not so broad as to 

 prevent the crossing of certain plants. 



On the assumption that the breach widened from the north, 

 the opposed shore-lines would have approached closest in the south, 

 namely in about a line from Uruguay to the Cape. A little farther 

 -on it is pointed out that a much more northerly connection might 

 .also have come into being at about the same date. 



Cut off by the Upper Cretaceous Ocean, just as Africa was, 

 .'South America started to evolve a marvellous assemblage of mam- 

 malian life, such as the gigantic ground-sloths and armadillos, the 

 remains of which are preserved in the Tertiary deposits of Eastern 

 JPatagonia. 



The Reunion of South America and Australia. 



Meanwhile the several sectors of Gondwanaland were moving 

 .apart from one another at a more rapid rate and, as explained 

 -earlier, they were pushing up in front of them a practically com- 

 plete circle of fold-ranges, bringing above the surface of the ocean 

 parts of the crust that had been forming the sea floor for a very 

 lengthy period. 



In South America this resulted at the beginning of the Miocene 

 in the elevation of the Andes, a chain of crumpled beds injected 

 with igneous matter, prolonged southwards through Graham Land 

 .and Western Antarctica, and continued in the folds of New Zealand 

 and Eastern Australia. Von Ihering, Ortmann and Hedley have 

 •emphasised the great resemblances in the marine molluscan faunas 

 of this date in Patagonia, Australia, and New Zealand, indicating 

 a migration of forms along the littoral of a Miocene ridge. 



Zoologists have had occasion to remark upon the relationships 

 displayed between the marsupials of Patagonia and those of Aus- 

 tralia and Tasmania, and when to this is added similar evidence 

 from among the fossil turtles, the fresh-water fishes, the decapod 

 'Crustacea, the land Mollusca, and the earth-worms, there can be 

 no reason to doubt that a land-bridge connected these parts of the 

 globe. The botanical affinities, as shown by Hooker, Hemsley, and 

 Bentham, point strongly in the same direction, the relationships 

 being much more marked than with Africa. 



It. is essential to note that this period, the Miocene, was one 

 of remarkably mild climate, which alone could have permitted the 

 migration of terrestial life via the Antarctic Circle. 



Atlantis. 



Turning to the north of South America, but arguing wholly 

 upon analogy, we are able to detect a second locality where a con- 

 nection with Africa could have been established during the 

 'Tertiary, for between Venezuela and Morocco the Cretaceous and 



12 



