178 ANCIENT PLANTS 



those now extant. This shows us how very far from 

 the beginning our earliest information is, for already in 

 the Palaeozoic we have a flora as diversified as that 

 now living, though with more primitive characters. 



In Mesozoic times the most striking group is that of 

 the Cycads and Bennettitales, the latter branch suggest- 

 ing a direct connection between the fern-cycad series 

 and the flowering plants. This view, so recently pub- 

 lished and upheld by various eminent botanists, is fast 

 gaining ground. Indeed, so popular has it become 

 among the specialists that there is a danger of over- 

 looking the real difficulties of the case. The morpho- 

 logical leap from the leaves and stems of cycads to those 

 of the flowering plants seems a much more serious 

 matter to presuppose than is at present recognized. 



As is indicated in the diagram, the groups do not 

 appear isolated by great unbridged gaps, as they did 

 even twenty years ago. By means of the fossils either 

 direct connections or probable lines of connection are 

 discovered which link up the series of families. At 

 present the greatest gap now lies hedging in the Moss 

 family, and, as was mentioned (p. 163), fossil botany 

 cannot as yet throw much light on that problem owing 

 to the lack of fossil mosses. 



This glimpse into the past suggests a prophecy for 

 the future. Evolution having proceeded steadily for 

 such vast periods is not likely to stop at the stage 

 reached by the plants of to-day. What will be the 

 main line of advance of the plants of the future, and 

 how will they differ from those of the present? 



We have seen in the past how the differentiation of 

 size in the spores resulted in sex, and in the higher 

 plants in the modifications along widely different lines 

 of the male and female; how the large spore (female) 

 became enclosed in protecting tissues, which finally 

 led up to true seeds (see p. 75), while the male being 

 so temporary had no such elaboration. As the seed 



