CHAPTEK YI 



THE EEIGN OF REPTILES 



At some periods in tlie history of the earth 

 life seems to have flourished mth unwonted 

 vigor, and to have developed into such strange 

 forms that it would seem as if Nature had 

 fairly reveled in the creation of new and won- 

 dei^ful shapes. The Carboniferous was the 

 golden age of ferns and mosses, when warmth, 

 moisture, and an atmosphere heavy with car- 

 bonic acid combined to stimulate the growth 

 of these now lowly plants into great trees, 

 which sprang up, flourished, and decayed, trans- 

 forming the imprisoned sunlight into beds of 

 coal for the use of future ages. And just as 

 the labyrinthodonts flourished with the coal- 

 forming plants so that during the Carbonifer- 

 ous period amphibians reached their highest 

 level, so the Jurassic dinosaurs mark the cul- 

 mination of reptilian life in point of size and 



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