56 



OPHIOGLOSSACEAE 



[CH. 



monarch roots: this was suggested by Van Tieghem, who remarks that if 

 the monarch root divides, we know beforehand that it will dichotomise 

 (Ann. Sci. Nat., v Serie, T. xiii, p. io8). The larger polyarch roots of the 

 family have a structure reminiscent of other Ferns, and particularly of the 

 Marattiaceae. It is a tenable view that the simpler roots are reduced from 



Fig. 347. Helniinthostachys zeylanica: part of a transverse section of a root (Gwynne-Vaughan 

 Coll. slide 589. X 66). The endodermis, recognised by the characteristic structure of its radial 

 walls, marks a boundary between the outside cortex, with large starch grains (here above) and 

 the inner conjunctive parenchyma (here below), with smaller starch grains. (Drawn by Dr J. M. 

 Tiiompson.) 



Fig. 348. Ophioi^lossiiin Bcrgiaiiii/it Schleclit. Transverse sections 

 of the stele of llie root, the one showing two unequal groups of 

 xylem, the other only one. ( x 200.) 



