THE FORESTS OF LONG AGO 



45 



terminated multitudes. One 

 faces the fact that the present 

 type of plants and trees inhab- 

 iting the earth today is only 

 one of the many different 

 types that must have existed 

 since plants began. 



This, then, in briefest out- 

 line is the epic of plant life in 

 this world of ours. The be- 

 ginning of it all extends back 

 many millions of years it is 

 a continuous pageant of life 

 passing across the centuries. 

 First the simplest kinds of 

 tiny water plants, later the 

 ferns and club mosses, then 

 the more highly specialized 

 cone-bearing trees and last and 

 most complex of all, the 

 broad-leaf trees, the highest 

 forms of plant life in the 

 world today. These changes 

 still go on for just as the 

 climate is changing slowly, 



GINKGO LEAVES PAST AND PRESENT 

 The three upper leaves (1-2-3) are 

 fossil remains of leaves from the ances- 

 tors of the maidenhair tree or ginkgo 

 biloba. The lower leaf (4) is a modern 

 specimen. 



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