376 Plants and their Ways in South Africa 



That such a connexion existed until after the Antarctic glacial period in 

 Permian times, is generally admitted by geologists. Types common to 

 South Africa and to South America may have found their way to the 

 latter country from Australia by a land connexion after that between 

 South Africa and Australia had been severed. This supposition is 

 strengthened by fossil land tortoises common to Australia and Patagonia 

 and by the fossil remains in Patagonia of an animal which seems to have 

 been identical with the present Tasmanian wolf. The discovery in 

 recent times of a marsupial in South America belonging to a division 

 (Diprodonts) hitherto known only in Australia may also tell of a long 

 southern migration over this same land bridge, Antarctica, from Australia 

 to South America. It is true that fossil marsupials are found in North 

 America and Europe (division Polyprodonts), even earlier than any in 

 South America. It may be that the northern division found their way 

 south giving rise to the southern diprodonts, which then migrated to 

 South America from Australia. 



Amundsen and Scott in their expeditions to the South Pole secured 

 interesting geological information bearing on this problem. The associa- 

 tions of rocks and the nature of the coal seams found in Antarctica serve 

 to strengthen the view that the South Polar Regions are geologically a 

 continuation of the Andes and of Tasmania and West Australia. How- 

 ever this may be, the similarity of the flora may be due in part to the 

 plankton carried by ice-bergs and to the agency of winds. It is interest- 

 ing to note in this connexion that Dr. Fritsch found the pollen of Podocar- 

 pits in material from the South Orkneys which he thinks must have been 

 brought from South America, and Mr. Brown attributes to the agency of 

 birds the presence of the Arctic mosses. 



From geological evidence it is also thought that, after the land con- 

 nexion between South Africa and Australia was severed, South Africa 

 remained connected with India through Madagascar. (In Permo Car- 

 boniferous times, forming what is known as Gondwanaland.) 



It is a much-disputed point as to whether there was a land bridge 

 between South America and West Africa late enough, if at all, to account 

 for an interchange of animals and plants between those two countries. 

 How the South African Gloriosa (Liliaceae) found its way to South 

 America and the so-called Transvaal lily (Order Bromeliaceas) found its 

 place in Rhodesian mountains is as puzzling a question as to account for 

 the Edentates and fresh-water i fish that are common' to these two 

 countries. 



In the Eastern portion of South Africa the flora has gradually re- 

 ceived forms from the southern migration of tropical plants while the 

 southern forms were advancing north along the highlands. The northern 

 forms have met the older flora of the south-western region and have 

 partly driven them back. In the neighbourhood of Grahamstown, East 

 London and Pondoland, signs of conflict between the old and the newer 

 flora may be seen. Fossil forms show a meeting of the southern 

 (Angiopteris) flora with the northern (Sigillaria) at Vereeniging. 



