THE EARLIEST LAND-PLANTS 45 



' Of the main divisions of the Vegetable Kingdom the 

 Angiosperms alone appear to originate within the periods 

 of which we have any adequate fossil record. They do 

 not appear, as at present known, until late in the Mesozoic. 

 Some affinity between them and the much more ancient 

 Cycadophyta is indicated by the latest work. 



' The other seed-plants go back certainly to the 

 Devonian we do not know how much further. During 

 Palaeozoic times there was a great group of seed-plants 

 the Pteridospermeae of a relatively primitive type, 

 showing affinity with Ferns. Most of the so-called 

 Palaeozoic " Ferns " were really seed-bearing plants of 

 this kind. 



' But, side by side with them, and going back equally 

 far according to present records, there were the Cor- 

 daiteae, a well characterized family of Gymnosperms com- 

 parable in many respects to the Coniferae. 



' Hence the evolution of seed-plants had already reached 

 a very advanced stage at the period to which our earliest 

 satisfactory records of land-plants belong. 



' It is thus only a very small fraction of the whole 

 course of plant-evolution which is revealed in the fossil 

 record.' 



