70 THE EVOLUTION OF PLANTS 



as big as a peach; they also resemble a peach or 

 plum in structure, for the outer part is soft and 

 fleshy, and encloses a stone. The whole organ, 

 however, is here an excessively developed seed, 

 whereas in the peach everything except the ker- 

 nel inside the stone belongs to the fruit. In 

 some species of Cycas there is the same brilliant 

 contrast of colour which we mentioned in En- 

 cephalartos. In Cycas revoluta the bright-red 

 ovules or seeds on their yellow carpels have a 

 very gay appearance. 



We see then that the Cycads as a family are 

 decidedly simpler in their reproductive arrange- 

 ments than other Seed-plants. Cycas hi partic- 

 ular, as regards the female plant, stands quite 

 alone, as the only living genus of seed-bearing 

 plants in which neither flower nor cone is devel- 

 oped; the carpets are not only obviously leaf- 

 like in form, but are borne, among the ordinary 

 green leaves, on the main stem of the plant. 



But there are other points in which the Cycads 

 even more clearly betray a primitive character 

 among Seed-plants, approaching the Spore-plants. 

 This is most strikingly shown in their mode of fer- 

 tilisation, discovered fourteen years ago by two 

 Japanese botanists Hirase and Ikeno and in- 

 pendently just afterwards by Webber in America. 

 . Like most of the Cryptogams, but unlike any other 

 living Seed-plant except the Maidenhair-tree, 



