INTRODUCTION. Xllll 



Grondwanaland by Feistmantel, but wbicli iu reality is entirely 

 unrepresented in that flora. The attributions to the genera 

 Actinopteris and Asplenium are other cases in point. 



With regard to the nature of the climate of Gondwanaland 

 there is no evidence to be gained from the plant-remains as they 

 are at present known. This is particularly unfortunate, since it 

 would- seem to be impossible to account for tbe differences between 

 the northern and southern floras by the mere fact of isolation 

 alone. It would appear that climate as well as isolation must 

 have had a determining influence on the distribution of Perino- 

 Carboniferous vegetation. 1 Probably the existence of widespread 

 glacial conditions immediately preceding the deposition of the 

 earlier Glossopteris-beaxing sediments had a marked influence in 

 this connection. 2 Dr. Blanford 3 has suggested there is "some 

 evidence in favour of the view that the transfer of the southern 

 plants to the Northern Hemisphere was caused b\- a period of low 

 temperature that drove a southern temperate flora northward to 

 the equator." He adds that "it is highly probable 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." 



1 W. T. Blanford (90), p. 96. 



• Sec Seward (03-),' pp. 834-5 ; II. F. Blanford (75), pp. 534, 510. 



3 W. T. Blanford (90), pp. 105-6. 



