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ANNUAL REPOET SMITHSONIAN INSTITUTION, 192 8 



how. this flora was dispersed. Some hold that it traveled across a 

 land bridge from Brazil to Africa and thence to India, and others- 

 postulate a bridge from South America to Antarctica and from here 

 another one to Australia. It is not even known where this flora origi- 

 nated (some paleobotanists think in Antarctis or Australia), but if it 

 arose in South America and went over a land bridge to Antarctis, 

 the rest of the distribution might have been by way of oceanic cur- 

 rents, just as South and Central American and Asiatic dicotyledons 

 have in Cenozoic time reached the Hawaiian Islands, which have 

 always been isolated volcanic masses. On the other hand, David 

 White points out that the younger Permian flora is clearly, through 



Figure 3. — Pangaoa of Carboniferous time as illustrated by Kopp-en and Wegener in 

 Die Klimate dtr geoloijisclten Vorzeit, 1024. E, glacial e\-idence (introducid in 

 part by Schuchert) ; K, coals; S, salt; G, gyps;um ; W and dotted areas, deserts 



climatic rigors, a highly modified outgrowth of the world-wide Coal 

 Measures flora, and so it may well be that it arose in several places 

 and through migration and combination with the hold-overs of the 

 older floras became the well-known GJossopteris flora. 



Lake ^~ has gone at length into the distribution of the Glossopterls 

 flora, and makes the following points: The Glossoptens flora is 

 found also in Kashmir, northwestern Afghanistan, and northeastern 

 Persia, Tonquin, northern Eussia, and Siberia. In Russia it is ac- 

 companied by South African reptiles and fresh-water shells. 



Wegener's explanation has not by any means simplified the problem of the 

 distribution of the Glossopteris flora and fauna. 



Lake then considers the distribution of the Permian tillites and 

 says: 



"Philip Lake, Natuiv. Feb. 17, i;t23. p. 227. 



