XX] 



ANATOMY 



107 



without endodermis apparently, and so it would be comparable to some Ophioglossaceae. 

 It may be recognised as the earliest recorded solenostelic Fern. Structurally it appears to 

 represent an ontogenetic stage which the larger Marattiaceae pass rapidly through. The 

 next as regards complexity is /". musaeformis {Y\g. 400, D), a species from the Lower Permian 

 of Chemnitz. It is one of the Distic/u\ with leaves in two rows, the leaf-traces passing off 



Fig. 401. Fsaroiiiiis Renaulti. Part of transverse section of stem, 

 showing a portion of the solenostele. On the left is the edge of a 

 leaf-gap. In the stele, note the protoxylem-groups on the inner 

 edge of the wood. The phloem, with large sieve-tubes, is well 

 preserved on the outer side. The dark elements in the perl cycle 

 are secretory sacs. (X13.) S. Coll. 2174. (From a photograph 

 by Mr Tarns, after Scott.) 



right and left from the polycyclic stele, which is here seen as four pairs of continuous 

 vascular tracts. The drawings of Zeiller of P. Demolci are specially interesting, since 

 he shows two stems of different sizes : the smaller has only three vascular cycles, the 

 larger has 4-5 cycles. In the next three species quoted in the table a highly polycyclic state 



