LEAVES. 



91 



PLATE XXXIX. 



FIG. 49. Powdered Tobacco Leaves (x 240). 



ccn, Cells with sandy crystals. 



ei, Lower epidermis. 



en, Neural epidermis. 



es, Upper epidermis with stomata. 



ffv, Fragments of fibrovascular bundle. 



me, Cells of spongy parenchyma. 



P> P 2 f P 8 , Long pluricellular hairs with unicellular or pluricellular 

 glands. 



p 4 , p 5 , Short glandular hairs. 



p 6 , Conical, pluricellular simple hair 



pa, p'a', palisade cells. 



st, Stomata surrounded by three cells, one of which is smaller than the 

 others. 



tr, Tracheids 



v, Vessels. 



