56 THE THEORY OF EVOLUTION 



(Lepidodendron) (Fig. 14), and Sigillaria 1 and the 

 Calamites. 



FlG. 15. A RECONSTRUCTED CORDAITE. 



FIG. 14. A RESTORED LEPiDO- The flower scapes may be seen on the 



DENDRON. separate branches between the leaves. 



The Gymnosperms are represented by the Corda- 

 ites (Fig. 15), which soon disappeared ; they were 

 large trees with sometimes gigantic leaves, which there- 



i Schuppenbaume (lit. scale trees : Lepidodendrse) derive their name 

 from the cushion-like elevations (scales) on the bark which bear the scars of 

 the fallen leaves. The Sigillaria (lit. seal trees) do not show these cushions 

 or scales ; the leaf scars lie flat upon the bark, and are hexagonal. 



