THE GENESIS AND MIGRATIONS OF PLANTS 229 



have verified these for the Devonian and Carboniferous of the 

 United States, and to some extent also for those of Europe. 

 To the same effect is the recognition of the Kootanie or 

 Lower Cretaceous, the Middle Cretaceous, Upper Cretaceous, 

 I>aramie and Miocene in Western Canada. These have in all 

 cases corresponded with the indications of animal fossils ^ and 

 of stratigraphy. Fossil plants have been less studied in this 

 connection than fossil animals, but I have no hesitation in 

 affirming that, with reference to the broader changes of the 

 earth's surface, any competent palseobotanist is perfectly safe 

 in trusting to the evidence of vegetable fossils. 



It may be objected that such evidence will be affected by the 

 migrations of plants, so that we cannot be certain that identical 

 species flourished in Greenland and in temperate America at 

 the same time. If such species originated in Greenland and 

 migrated southward, the specimens found at the south may be 

 much newer than those in the north. This, no doubt, is 

 locally true, but the migrations of plants, though slow, occupy 

 less time than that of a great geological period. It may also be 

 objected that the flora of swamps, plains, and mountain tops 

 would differ at any one period. This also is true, but the same 

 difficulty applies to animals of the deep sea, the shore, and the 

 land ; and these diversities of station have always to be taken 

 into account by the palaeontologist. 



References : — Report on the Erian or Devonian Plants of Canada, 

 Montreal, 1871. Article in Princeton Keviav on Genesis and 

 Migrations of Plants. " The Geological History of Plants," London 

 and New York, 1888 and 1892. Papers on Fossil Plants of Western 

 Canada, 1883, and follov,'ing volumes of Transactions of Royal 

 Society of Canada. 



Note. — Since writing the above, I have obtained access to Dall and 

 Harris' " Neocene Correlation Papers," -which throw some additional 



^ Reports on Fossil Plants of the Devonian and Lower Carboniferous, 



