ig6 SCIENCE PROGRESS. 



author ^ writes : "The discovery in several different parts 

 of South America of Gaiigamopteris and Neuropteridmmy 

 associated in the same beds with Lepidodendron, may 

 perhaps imply that a land connection existed in newer 

 Palaeozoic times in the American area between the continent 

 of the Northern Hemisphere and Gondwana Land". A 

 consideration of the full significance of the recent discovery 

 in South Africa of a lepidodendroid plant in association 

 with Glossopteris is deferred until the material has been 

 more fully investigated. 



In dealing with an assemblage of extinct plants, it is 

 extremely difficult, not to say impossible, to arrive at any 

 definite conclusion as to the climatic conditions under which 

 the different genera and species existed. We cannot ad- 

 duce any trustworthy evidence from the plants themselves 

 to warrant the assumption that the Glossopteris flora was 

 well fitted to withstand a cold climate ; but external 

 evidence favours the conclusions as to climatic chanpfes 

 having been in a great measure responsible for the 

 existence of two distinct botanical provinces during the 

 Permo-Carboniferous era. Unfortunately we possess but 

 little exact or complete botanical knowledge of the Southern 

 Hemisphere plants ; the work of Feistmantel and others 

 has made us familiar with the various leaf forms char- 

 acterised in many instances by their large size and anas- 

 tomosino- veins, but we are still without information as to 

 internal structure and reproductive organs of the typical 

 genera of the Glossopteids flora. 



A more detailed and extended study of the Upper 

 Palaeozoic plants of the Southern Hemisphere, and a careful 

 comparison of the homotaxial floras north and south of the 

 equator, should lead to important generalisations interest- 

 ing alike from the point of view of geographical botany, 

 and the distribution of land and water at the close of the 

 Palaeozoic era. 



iBlanford (5), p. 59. 



