A NEW MEDULLOSEAN^ STEM. 



103 



Plate 11. 



Fi'^. 1. A photograph of the decorticated stem-fragment, showing the external appearance ; a, ground- 

 tissue ; St, stelar tissues. Nat. size. 

 Fig. 2. The inner margin of partial stele b, showing protoxylems {px) and uniseriate medullary 



rays [mr) . x 70. 

 Fig. 3. Stele 3, from Section A (c/. fig. 8), a fairly typical example of an inner stele : /, trace ; 



pm, partial pith. X 5. Note the arrangement of the xylem elements and the outlmmg of 



dark crushed tissue. 

 Fig. 4. Brown tissue of stele 10 (from Section B), showing radial arrangement of elements : 



s, sclerotic nests. X 70. Note the structure of the xylem, with uniseriate medullary rays. 



Fig. 5. Xylem elements, showing hiseriate pitting. x325. 



Fig. 6. Portion of periderm band in arch of central stele (Section B). The periderm 



strand of xylem elements (a-^") . x 70. (C/. PL 10. fig. 11-) 

 Figs. 7 & 8. Sections B and A respectively. X 2. Steles and partial steles are numbered and lettered 



as in PI. 10. fig 1 : cs, central stele ; pd, epiderm bands ; vh, isolated vascular strands. 



{pd) 



SECOND SERIES. — BOTANY, VOL. VIII. 



Q 



