THE EVOLUTION OF PLANTS 



dant fossil remains. They have also been called Pteridosperms, 

 or seed-bearing ferns (Fig. 8) . From these descended cycad- 

 like plants, which had features resembling those of modern 

 flowering-plants of 

 primitive type and 

 which are called 

 Pfo-angiosperms. 

 From this stock are 

 descended the mod- 

 ern eye ads (Figs. 9 

 and 10) and the 

 two great groups of 

 flowering plants — 

 those with two seed- 

 leaves (dicotyledons 

 — ^magnolias (Fig. 

 12) , buttercups, 

 roses, bell - flowers, 

 dandelions, etc.), 

 and those with one 

 seed - leaf (^mono- 

 cotyledons — lilies 

 (Fig. 14), grasses, 



Fig. 4. — Hair-cap moss (Poly- 

 trichum commune) . A, male plant; 

 B, same, reproducing vegetatively, 

 growing from the tip of another; C, 

 female plant bearing a spore-case on 

 a long, slender stalk. This spore- 

 bearing phase of the plant (sporo- 

 phyte) is developed from an egg-cell 

 after it had been fertilized by a 

 sperm from a male plant. 



Reproduced, by permission, from 

 Gager's Fundamentals of Botany, 

 published by P. Blakiston's Sons & 

 Co. 



[147] 



