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cortical, or outer part, the mesophyll, or chlorophyll-bearing part, and the 
fibro-vascular region surrounded by its bundle sheath. 
The cortical region is composed of an epidermis and a series of 
strengthening cells lying directly beneath. The epidermis is composed of 
ABIES MAGNIFICA. 
D Duets. M Mesophyll. 
F Fibro-vas. bundle. E Epidermis. 
B_ Bundle sheath. S Strength. cells. 
a single layer of thick-walled cells with a cuticle twice as thick as the 
lumen of the cell. This epidermis is broken by the openings of the 
stomata. These stomata are arranged in rows down the sides of the leaf 
