THE ROMANCE OF OUR TREES 



This earliest luxuriant land vegetation — that 

 which formed the great coal-fields of the earth — was 

 probably adapted to the physical environment alone 

 and was almost uninfluenced by the scanty animal life 

 of the period. Reptiles and mammals were then 

 differentiated, but the former, being better fitted to 

 live upon the vegetation and to survive in the heavily 

 carbonated atmosphere, increased more rapidly. 

 This increase continued through the next two geolog- 

 ical epochs and culminated in the next, the Jurassic 

 period, which has been fitly termed the "Age of Rep- 

 tiles." Rocks of this age are prevalent in the states 

 of Wyoming, the Dakotas, Kansas, and Texas, and 

 from them have been excavated, and sent to museums 

 for preservation, remains more or less complete of 

 the largest, the ugliest, and the most extraordinary 

 forms of animal life the world has known. 



The development of vegetation reacting on the 

 climate and on the animal kingdom, and each on the 

 other, induced constant change. In due course rep- 

 tiles gave place to mammals, birds were differenti- 

 ated and likewise insects in variety; Cycads, Arau- 

 carias, Ginkgos, Yews, Cedars, and other conifers 

 came into being and, later, broadleaf and coniferous 

 trees similar to those of to-day. It is not my purpose 

 to trace this progressive change in further detail but 

 the fact I do wish to emphasize is that isolated types 

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