696 



C. SKOTTSBERG 



time? If, during the Tertiary, a glaciated Polar cap was situated elsewhere, 

 the basis for our discussion above is removed. So far it is an established fact 

 that the Glacial periods in South America, New Zealand, Antarctica and the 

 North Hemisphere were all of them simultaneous. 



If we extend the coast of South America westwards to the longitude of 

 Juan Fernandez, this coast will still be washed by a -Peruvian Current*, and an 

 upwelling region will give rise to a cold coast current. Those who believe in 

 the crypto-oceanic character of the islands on the Juan P'ernandez rise favour 

 the idea of such an extension during early Tertiary times or even later. The 

 flora and fauna of this hypothetical coast were a common source of the flora 

 and fauna of the Juan Fernandez land and of the new coast of the continent. 

 The submergence of a wide area, followed by the eastward migration of the 

 current, explains the resemblance as well as the difi'erence between the islands 

 and the mainland. The Subtropical element became reduced in inshore waters, 

 and during the Glacial Period the difterences increased. The Magellanic organisms 

 migrated northward and receded during the Postglacial, the large La))iina7'iaccae 

 and Fiicaccae disappeared from the islands (if they ever occurred there). Some 

 species managed to cross from the islands to the continent and vice versa, 

 others which formerly had a wider range, became restricted to the islands. As 

 far as I can see, the present distribution of both plants and animals does not 

 speak against the existence of a former Juan Fernandez land connected with 

 South America, and cannot be taken as a proof of the oceanic nature of the 

 present islands, as Plate does. It is possible that this connection was coin- 

 cident with a South American — Antarctic bridge, but I shall not consider this 

 problem here. 



My thanks are due to the Director of the Oceanographical Institute of 

 Goteborg, Dr. Hans Petterssox, who kindly selected the oceanographical 

 literature cited above. 



P/infed ' 12 194T. 



