80 PLANT-LIFE ON LAND [CH. v 



only as G. biloba, the Maiden-hair Tree of China and 

 Japan. Such facts give additional weight to the 

 conclusion which has been drawn. They show in the 

 form of practical results how essential that emanci- 

 pation was, in order that full advantage might be 

 taken of the opportunities offered by life upon 

 exposed land surfaces. 



