THE ORIGIN OF PLANT LIFE ON THE LAND, iii 



appeared for the first time in the Coal-formation, we might have 

 supposed :hat they had been developed from such Lycopods 

 as Lepidodendra, and that the Cordaites are the intermediate 

 forms ; but unfortunately the Pines go almost as far back in 

 geological time as the Lycopods, and it does not help us, when 

 in search of evidence of evolution, to finrl the link which is 



iV 



Fig. tox. — Trigonocarpum Hookeri {Dn^. A Gymnospermous seed. 

 a, Testa, b, Tegmen. c. Nucleus, d, Embryo. 



missing or imperfect in the Early Devonian supplied in the 

 Coal-formation, where, for ihis purpose at least, it is no longer 

 needed. 



We have said something of what was in the Palaeozoic flora ; 

 but what of that which was not ? We may answer : — Nearly 

 all that is characteristic of our modern forests, whether in the 

 ordinary Exogens which predominate so greatly in the trees and 



