FOSSIL FORESTS OF YELLOWSTONE PARK. 



29 



presence of numerous species of figs, a supposed bread-fruit tree, 

 cinnamons, bays, and other southern phints indicates that it may 

 have been ahnost subtropicaL However, the conditions that were 

 favorable to this seemingly subtropical growth may have been dif- 

 ferent from the conditions now necessary for the growth of similar 

 vegetation. It may be that these supposed subtropical plants Avere at 

 that time so constituted as to grow in a temperate land, and that they 

 may have become tropical in recent times. Following this general 

 line of thought it may be said that althougli the Tertiary vegetation 

 of the Yellowstone National Park would noAV be regarded as indi- 

 cating a temperate or even warmer climate, the actual climate may 

 not have been subtropicaL It is certain, however, that the conditions 

 were very different from those now pi-evailing in- the park. 



