8 GENERAL BIOLOGY. 



subepidermis thinner at the lateral 

 ridges. 



(b) The light-colored ground- substance or 



fundamental parenchyma, forming most of 

 the stem. 



(c) The dark interrupted ring of sclerenchyma 



(sclerotic prosenchyma). 



(d) Small patches of sclerenchyma outside 



the main ring. 



(e) Yellowish tissue (fibrovascular bundles) 



lying ID side and outside the ring of 

 sclerenchyma. 



2. Cut a small piece of rhizome in a longitudinal 



vertical plane. 

 Find on the cut surface (a), (6), (c), (d), (e\ in 



II. 1. 

 Sketch. 



3. Cut a thin transverse section of rhizome, mount 



in water, and examine with the low power. 

 Find the different kinds of tissues, as in II. 1, 



(a), (6), (c), (d), (e). 



Make a diagram to show the outlines of the different 

 regions. 



4. Treat the section with iodine and observe the 



result. To treat with iodine put a drop or two 

 of iodine on the slide close to the cover-glass, 

 and on the opposite side of the cover-glass draw 

 away the water from under the cover-glass ivith 

 a small piece of filter-paper. 



