384 



ANNUAL REPORT SMITHSONIAN INSTITUTION, 1918. 



and the loaves of Noeggerathiopsis and Euryphyllum, probably rela- 

 tives of the northern Cordaites. From the combined evidence of the 

 organisms, their distribution, and the continental character of the de- 

 posits, geologists have restored from the depths of the present seas a 

 vast southern continent extending from Australia to India and thence 

 to Africa and South America, which is called Gondwana Land and 

 which existed throughout the Permian and the first half of the Meso- 

 zoic. It was Aery probably connected southward from both Australia 

 and South America with the land mass in the south polar region 

 known as Antarctica, and a restricted land bridge connected it across 

 northwestern Africa with southwestern Europe. Elsewhere along its 

 northern borders a Mediterranean sea encircled the globe, separating 

 Gondwana Land from Angara Land (the ancient continental mass of 



Fig. 30.— Sketch map showing the geography and glaciation of the Permian. 



Asia) and from Eria (North America). It was upon this Gondwana 

 continent or on the Antarctic continent to the southward that the 

 Glossopteris flora had its inception. 



It was the climatic changes resulting from this widespread emer- 

 gence and elevation of the land and the consequent alteration of the 

 oceanic and atmospheric circulation that furnished the stimulus for 

 its evolution, and these climatic changes culminated in a glaciation 

 that probably exceeded in its magnitude that of the more familiar 

 and relatively recent Pleistocene Ice Age. These changes gradually 

 banished the more characteristic elements of the cosmopolitan flora 

 from this region, although it is known to have constituted the origi- 

 nal vegetation of the country, having been discovered in Lower Car- 

 boniferous or in Devonian rocks in South America and Australia and 



