NOTES ON SUB ANTARCTIC FLORAS 141 



antarcticum Gothan is another example of the New Zealand 

 element in the Seymour flora, not found in South America. 



With these facts at hand it becomes evident that there existed 

 an Antarctic Tertiary flora bearing resemblances to the present 

 floras of Subantarctic America, New Zealand and Australia, and 

 that the Antarctic Continent may have been a centre of evolu- 

 tion from which animals and plants wandered north. It is pos- 

 sible that the endemic element in other austral insular floras 

 had the same origin, as for instance a type like Pringlea, now 

 limited to the Kerguelen group. There probably also took place 

 an interchange of species across the South Polar lands. I have 

 already mentioned that a great many biologists, as well as geolo- 

 gists, believe in a formerly much larger Great New Zealand. And 

 for Subantarctic America it seems probable that the Falkland 

 Island were connected with the mainland at some time during 

 the Tertiary. Both geological and bathymetrical conditions 

 speak in favor of the well-known hypothesis boldly continuing 

 the Andes over South Georgia, the South Sandwich and South 

 Orkney Islands to Graham Land. That the sea between some 

 of the links in this broken chain can not be styled as shallow, 

 I do not regard as an insurmountable obstacle, for we know 

 that the upheaval of the Andes was connected with the submer- 

 sion of land, so that enormous depths of recent origin resulted 

 right along the present coast line of Chile. The Antarctic Con- 

 tinent may have been more extensive in Preglacial time. The 

 upheaval of the once ice-covered parts of Europe and North 

 America after the recession of the inland ice has been interpreted 

 as due to a tendency in the earth's crust to regain isostatic con- 

 ditions, the weight of the ice having caused a considerable de- 

 pression. Such a theory may as well be applied to the Antarctic 

 Continent, submerged under the tremendous pressure of the most 

 extensive inland ice that ever existed (save for the time when the 

 same ice sheet was larger still than it is now). 



Even if we admit Tertiary land communications, or at least 

 much greater facilities for the migrations of plants and animals 

 than now, everything in the present distribution can not be ex- 

 plained in this way. South Georgia offers a good example of this. 



