472 



COENOPTERIDEAE 



[CH. XXV 



of stele reaches a higher degree, with the result that a style is 

 evolved which agrees closely with that of the conducting tissue 

 of some existing Dicotyledonous Lianes. 



Attention has already been drawn to the generalised features 

 exhibited by the Coenopterideae both in the anatomy of the 

 steles and in the structure of the sporangia. The conclusion 

 arrived at is that while the Coenopterideae foreshadow in some 



Fia. 324. Atterochlaena laxa : part of stem with petiole and a few roots. 

 From Xansley, after Stenzel. 



of their characters more than one group of more recent ferns, 

 some at least of their members afford convincing evidence of 

 the correctness of the view— which is also that of Dr Kidston 

 and Mr Gwynne-Vaughan — that the Osmundaceae and the 

 Coenopterideae are offshoots of a common stock. 



