OF UPPER EOCENE CLIMATES. 3 



cal, sub-tropical, and temperate rain forest floras of South America, 

 I am convinced that no known fossil flora of Cretaceous or Tertiary- 

 age in the United States can properly be called tropical in any but a 

 most loose and uncritical use of that term. Much less can it be ' 

 applied to the Arctic Tertiary floras. It is true that many of these 

 fossil floras indicate warmer climatic conditions th^n prevail at the 

 present time in the same latitudes, and it is also true that many of 

 their elements have a seemingly unusual latitudinal range. 



Most temperate rain forests of the present would have been pro- 

 nounced " tropical " by paleobotanists if they occurred as fossils, and 

 I have repeatedly called attention to the resemblance of our Atlantic 

 Coastal Plain Upper Cretaceous floras to temperate rain forests, in 

 which the same mingling of types is observed. 



Most of the familiar plants that are enumerated in fossil floras 

 as being of especial, that is, tropical climatic significance, belong to 

 large genera whose species have a wide range and have become 

 adapted to a variety of habitats. Take, for example, palms, which, 

 in my experience in the Yungas of Bolivia, stick closely to the tropical 

 and sub-tropical altitudinal zones ; and we find some modern species, 

 incidentally very similar to a great many fossil species, ranging north- 

 ward as far as North Carolina, and southward as far as Valparaiso, 

 Chile. Another type frequently mentioned in fossil floras is the cin- 

 namon or camphor tree — the two most romantic names applied to two 

 of the many existing species of the genus Cinnamomum. The mod- 

 ern species range well into the temperate zone ; in fact, the commercial 

 supply of camphor comes largely from Formosa and Japan, the tree 

 being hardy as far north as about Latitude 35° in the latter country 

 with its oceanic climate. Introduced into Florida, Cinnamomum has 

 been seeded pretty widely by birds, and is perfectly hardy as far north 

 as Tallahassee in that state. 



Tree ferns constitute a third item in the paleobotanist's tropical 

 repertoire, although the most magnificent modern tree ferns are found 

 in temperate rain forests, such as those of New Zealand, on high 

 peaks in the tropics (above the tropical altitudinal zone), or in the 

 montaiia valleys of the Eastern Andes (above the tropical altitudinal 

 zone). The bread fruit is another spectacular fossil, ancl although 



