Fig. 1 86. — Amyelon radicans: (probably root of one of the C.'ordaitales) from the 

 lower Carboniferous of England; .v, protoxylem of triarch primary xylem; .v', secondary 

 xyiem; ph, phloem; pd, secondary cortex; X23. — After Scott.sj^ 



Fig. 187. — Amyelon sp. : (probably root of Cordaites) transverse section of tetrarch 

 root showing growth-rings; X9.— From a photomicrograph by Land of a section by 

 LoMAX. From Coulter and Chamberlain, Morphology oj Gymnos perms'^* (Univer- 

 sity of Chicago Press). 



