I02 ANCIENT PLANTS 



supposing that Ginkgo and Cordaites may have both 

 arisen from some ancient common stock. 



CHAPTER X 



PAST HISTORIES OF PLANT FAMILIES 



III. The Bennettitales 



This fascinating family is known only from the 

 fossils, and is so remote in its organization from any 

 common living forms that it may perhaps be a little diffi- 

 cult for those who do not know the Cycads to appre- 

 ciate the position of Bennettites. It would probably be 

 better for one studying fossil plants for the first time 

 to read the chapters on the Cycads, . Pteridosperms, and 

 Ferns before this chapter on the present group, which 

 has characters connecting it with that series. 



Until recently the bulk of the fossils which are found 

 as impressions of stems and foliage of this family were 

 very naturally classed as Cycads. They are extremely 

 common in the Mesozoic rocks (the so-called Age of 

 Cycads), and in the external appearance of both stems 

 and leaves they are practically identical with the Cycads. 



A few incomplete fructifications of some species have 

 been known in Europe for many years, but it is only 

 recently that they have been fully known. This is owing 

 to Wieland's^ work on the American species, which has 

 made known the complete organization of the fructifi- 

 cations from a mass of rich and well-petrified material. 



In the Lower Cretaceous and Upper Jurassic rocks 

 of America these plants abound, with their microscopic 

 structure well preserved, and their fructifications show 

 an organization of a different nature from that of any 

 past or present Cycad. 



1 See reference in the Appendix to this richly illustrated volume. 



