108 THE EVOLUTION OF PLANTS 



the glands that the seed was first identified; later 

 on it was found that the stalk bearing the seed 



Fig. 13. Lyginodendron. Longitudinal section of upper 

 part of seed; (r) integument; () space between integument 

 and pollen-chamber; (o) opening of pollen-chamber; (cc) 

 central column; (pc) cavity of pollen-chamber; (pg) pollen 

 in pollen-chamber; (mg) wall of megaspore. After Oliver. 

 X60. 



had just the same structure as the stalks of the 

 leaflets on the Lyginodendron frond. 



The seeds are excellently preserved, so that 

 it has been possible to make out most of the 



