210 SECTIONAL ADDRESSES. 



into at least two sharply contrasted regions, a northern region where rank 

 vegetation covered thousands of square miles of swamp and low hills, and 

 a vast southern continent where another and less luxuriant vegetation 

 flourished in proximity to retreating glaciers. 



An argument stressed by Prof. Schuchert in the presentation of his 

 case for the Middle Permian age of the Glossopteris Flora and the boulder 

 deposit is based on the marine fossils, which in some regions of Gondwana- 

 land are associated with the plant-beds. I have endeavoured to show that 

 the only piece of evidence furnished by marine fossils available in the Indian 

 Peninsula is unfavourable to his view. Moreover, the ParaZegroceras of Western 

 Australia and the South African crustacean Pygocephalus, leaving out of 

 account data furnished by the remains of other animals, support the 

 opinion that the Glossopteris Flora was evolved before the close of the 

 Carboniferous period. If the Glossopteris Flora is not older than Middle 

 Permian, we are left in complete ignorance of the state of the plant world 

 in Gondwanaland during the long interval between Lower Carboniferous 

 and Middle Permian time. The Glossopteris Flora, or at least members of it, 

 spread from a southern home as far as the province of the Kusnezk Flora 

 in Northern Russia and Siberia, where they grew in company with typical 

 Permian plants : at a still later date, as Mr. Harris, of Cambridge, has 

 recently shown, Glossopteris established itself as a member of the Rhaetic 

 Floras of Southern Sweden and Eastern Greenland. If, as is generally 

 admitted, the Kusnezk Flora is Permian, possibly Upper Permian in age, 

 this is consistent with a considerably earlier age for the Glossopteris- 

 bearing beds of Gondwanaland. There can be little doubt that Glossopteris 

 had its origin in the South, perhaps on a Palaeozoic Antarctica : it seems 

 reasonable to assume that the long journey from the far south across the 

 Tethys Sea began before the end of the Carboniferous period and was not 

 completed until some time in the Permian period. 



There is another point raised by Prof. Schuchert on which a word may 

 be said : he speaks of the Gigantopteris Flora of China as being overlain 

 by ' much younger and modified parts of the Gangamopteris VIotsl.' The 

 meaning of this is not clear : the flora in China, of which Gigantopteris, with 

 its handsome fern-like fronds, was a member, agrees in general character 

 with the late Carboniferous or early Permian Flora of North America and 

 Europe. So far as I am aware this flora has not been found in China, or 

 anywhere else, in direct association with a Gangamopteris Flora. The 

 interesting fact is that to the north of China there existed a vegetation 

 which included members of the Glossopteris or Gangamopteris Flora, while 

 farther south the vegetation was of the European and North American type. 



I have dwelt longer than I intended on certain questions connected 

 with the Glossopteris Flora, but the publication of Prof. Schuchert's 

 stimulating, and I would add, provocative article, is my excuse. He has 

 stated his case clearly, though not convincingly, and has collected a mass 

 of material for which many of us are grateful ; he has rendered good 

 service by directing attention to a problem which appeals both to geologists 

 and to palseobotanists. We are not yet in a position to make positive 

 statements on the age of the Glossopteris Flora or on the precise correlation 

 of the late Palaeozoic plant beds of Gondwanaland and those north of the 

 Tethys Sea. More evidence is needed ; and I venture to hope that Prof. 



