FERN. 9 



5. Examine a prepared stained transverse sec- 

 tion of rhizome. Study with the high 

 power. 



(a) Find again the tissues in II. 1, (a), (6), (c), 

 "(a)" The epidermis: a single layer of cells 



with very thick walls ; the subepi- 

 dermis (sclerotic parenchyma) : with 

 thick-walled cells. 



" (&)" The fundamental parenchyma : large 

 thin-walled cells with protoplasm, 

 nucleus, and starch-grains. 



" (c)" Sclerotic prosenchyma : smaller cells 



with thick walls. 

 Sketch a few cells of each kind. 



(b) In the fibrovascular bundle note : 



1. On the outside a single layer of 



flattened cells with brownish walls 

 and apparently empty (bundle- 

 sheath). 



2. Within the bundle-sheath a layer of 



parenchymatous cells containing 

 starch (phloem-sheath). 



3. Within the phloem-sheath is the 



phloem, consisting of : 



(a) Small cells with thick walls (bast- 



fibres). 



(b) A single row of large thin- walled 



cells (sieve-tubes or bast- vessels). 



(c) Small thin-walled cells lying be- 



