i6o DAVID WHITE 



striking floral changes, since the effects of so important a climatic 

 event must have been widespread. 



If, therefore, the glacial interruption did not occur at the close 

 of the Mississippian, as Bodenbender seems to see it, we may, I 

 think, continue provisionally to regard it as occurring at the close 

 of the Stephanian, or possibly (as would better suit many of the 

 facts) as late as the middle Permian. The totally unaffected aspect 

 of the topmost Stephanian flora near Mukden in Manchuria and 

 in Italy, as well as of the somewhat earlier Stephanian flora in 

 South Africa, w^ould, if evidence of other kinds to the contrary were 

 absent, tend somewhat strongly to prejudice in favor of the later 

 date. The moderate temperature of the fairly equable " Permo-Car- 

 boniferous" climate in general may explain why the shock of the 

 climatic episode w^as not more severely and for a longer time felt by 

 the cosmopolitan Permian flora of western Europe and America. 



