98 THE EVOLUTION OF PLANTS 

 CHAPTER IV 



THE EVOLUTION OF THE SEED-PLANTS 



THE Cycadophytes of the Secondary period, 

 as we saw in the last chapter, were very highly 

 organised plants, their dominant family, the 

 Bennettiteae, far surpassing the modern Cyc- 

 adacese and rivalling the Angiosperms them- 

 selves. This superiority of the old to the new 

 might seem surprising if we took the obvious 

 view that Evolution is a regular progression 

 from the simple to the complex. This, however, 

 is far from being the case; Evolution is to be 

 compared to the successive waves of a flowing 

 tide, rather than to the steady rise of a calm 

 river. In Mesozoic times the Cycadophytes 

 formed the wave that rose highest, but soon that 

 wave receded, and another followed and rose 

 higher still. 



The Cycadophyta, in fact, were then the domi- 

 nant class; there was nothing above them; 

 they were the best thing in the way of Flower- 

 ing Plants that then* age had produced; from 

 their triumphant success, overspreading all parts 

 of the world, we cannot doubt that they were 

 perfectly suited to the conditions then prevail- 

 ing. Later on, the conditions became more 



