20 COENOPTERIDACEAE [en. 



tation, whatever its origin, is less removed from the radial dichotom)' from 

 which the whole shoot of Ferns is believed to have sprung, than is the leaf 

 with bilateral symmetry deeply impressed upon it, which is characteristic 

 of all modern Ferns (Vol. I, Chap. v). 



Roots attached the plant to the soil. Their vascular supply arises usually 

 from the base of the leaf-trace. They are adventitious in much the same 

 way as in Ferns at large. Their stelar structure is as a rule that of the 

 ordinary diarch roots of Ferns. 



The Axis and Leaf-trace 

 The axis as a whole in Ankjroptei'is Gmyi may be as much as 22 mm. in 

 diameter, though usually less; that shown in Fig. 319 measures 18 mm. 

 Embedded within a broad cortex is the stele, with an outline as of a five- 

 rayed star, the rays being of unequal length. Its form follows that of its 

 xylem, which is usually the best preserved part (P^ig. 321). The five rays 



Fig. 321. Ankyroptcris Gray/. Stele, from a section in 

 Dr Kidston's collection. '( x i8.) (After Seward.) 



are in relation to the alternate leaf-insertion, which is on a two-fifths diverg- 

 ence. They are unequal, the least prominent having just parted with its 

 leaf-trace, while the most prominent is just about to do so. The leaf-trace 

 is a strand whose xylem takes a crescentic form with the concave side 

 directed outwards. It is nipped off from the margin of the ray, and passes 



