THE GLOSSOPTERIS FLORA. 195 



temperature. There is, moreover, good evidence for the 

 existence in Permo-Carboniferous times of a lar^e con- 

 tinental mass of land stretching across from Southern 

 Africa to India, and occupying part of what is now the 

 Indian Ocean. In all probability South America also 

 formed part of this Southern Continent, for which the name 

 of Gondwana Land ^ has been proposed. Over this con- 

 tinent, which formed a land connection between Australia 

 on the one side, and South America on the other, glacial 

 conditions obtained of sufficient extent to qIvg rise to the 

 thick mass of boulder beds already alluded to. It is natural 

 to suppose that there must have been a close connection 

 between the lowering of temperature in Gondwana Land 

 and the occurrence of the Glossoptcris flora. We may, 

 perhaps, assume that the Palaeozoic plant types were unable 

 to exist under the colder conditions, which on the other 

 hand favoured the extension of a flora of a different facies, 

 which may possibly have been derived from an antarctic 

 continent. In speaking of the Glossoptcris flora and the 

 existence of Gondwana Land, Blanford remarks that 

 perhaps the difference between the Upper Carboniferous 

 flora of the Northern Hemisphere and the contemporary 

 flora of the Southern Hemisphere, may be due to both 

 isolation and climate. He goes on to say, " there is, 

 moreover, some evidence in favour of the view that the 

 transfer of the southern plants to the Northern Hemi- 

 sphere was caused by a period of low temperature that 

 drove a southern temperate flora northward to the 

 equator",'^ " It is highly probable," he adds, "that many 

 other forms of terrestrial life besides the Mesozoic flora 

 originated in the Southern Hemisphere ; and unless a very 

 considerable area of what is now deep ocean was occupied 

 by land in Mesozoic and Palaeozoic times, a change in 

 favour of which there appears but slight evidence, it is far 

 from improbable that the antarctic continent was the 

 original area of development." In a later paper the same 



^ Suess, vol. ii., p. 318, see also Blanford (5). 



^Blanford (3), p. 105, see also Neumayr, vol. ii., p. 191. 



