56 THE EVOLUTION OF PLANTS 



CHAPTER HI 



THE EVOLUTION OF THE FLOWERING PLANTS 



THE EVIDENCE 



THE Secondary period has been called "the 

 Age of Gymnosperms," a description which 

 applies perfectly to the greater part of the period, 

 namely, from its beginning to the Cretaceous 

 epoch, in which, as we have seen, the Angio- 

 sperms made then- appearance. During the im- 

 mense tune represented by the deposition of the 

 Triassic and Jurassic rocks the Gymnosperms 

 were dominant in the Flora of the world, just as 

 the Angiosperms have been in later periods, 

 down to our own. The Age of Gymnosperms 

 extended into the Cretaceous epoch, for it is 

 only at a few places that Angiosperms have been 

 found in Lower Cretaceous rocks. When one 

 speaks of the Mesozoic or Secondary Flora, 

 without further explanation, it is this earlier 

 Flora which is meant, and not the later Angio- 

 spermous vegetation. 



The characteristic Mesozoic Flora became 

 fully established during the early part of the 

 Triassic epoch, and from then onwards the vege- 

 tation maintained a remarkably uniform char- 

 acter up to the early part of the Cretaceous era. 



