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Transactions. 



Sheathing Leaf -base (figs. 19-21). — This resembles the leaf in general 

 structure, but differs in a few details : (1.) The cells of the outer epidermis 

 are elongated at right angles to the surface. Like the epidermal cells of 

 the leaf, they have very thick walls, but here they are not lignified. The 

 inner epidermis is composed of roundish cells, with thickened lignified walls. 

 (2.) There is a cuticle on both surfaces, but it is not so thick as in the leaf. 

 (3.) Near the margins of the leaf all the cells, except those of the outer 

 epidermis, have thickened lignified walls. (4.) There is a hypoderma of 

 lignified cells on the upper surface. 



Fig. 22. — Dracophijllum UrviUcanum. Transverse section of stem 

 (X 175). a, thick cuticle ; i, epidermis; c, dead cortex ; 

 d, pericycle fibres ; e, suberized tissue ; /, phloem ; 

 g, medullary ray ; /;, xj^lem ; /, air-passage ; j, pith. 



Stem (fig. 22). — On the outside are the dead epidermal and cortical 

 cells. The epidermal cells are small, thick- walled, and have a very thick 

 cuticle. The cortical cells are irregular and thick-walled ; their walls are 

 suberized and also lignified. 



Inside this layer are some fibres which form a more or less continuous 

 band of small cells with very thick walls and small lumen. 



Then comes a band of corky tissue ; this is a moderately wide band, 

 and is composed of small regular thick-walled cells. 



The phloem is also a fairly wide band ; the phloem elements are very 

 regularly arranged, and the parenchymatous cells contain tannin. The 



