MICROSCOPICAL EXAMINATION 



505 



of Belladonna are large with wavy walls and the cuticle is striated, es, 

 Fig. 279; while Hyoscyamus has epidermal cells similar in every respect 

 excepting the striated cuticle, ei and es, Fig. 280. The spongy parenchyma 

 of Hyoscyamus contains numerous crystals of calcium oxalate, usually 

 in the form of prisms, cr, ccr, Fig. 280, while Belladonna is without calcium 

 oxalate excepting for crystal sand, which is contained in a few large cells 

 of spongy parenchyma adjoining the palisade parenchyma c, cr, Fig. 

 279. The presence of prismatic crystals in Hyoscyamus is the most 

 striking diagnostic character of these two powders. 



FIG. 278. Powdered Undulated Ipecacuanha. (X 210.) a, Starch grains, cr, Acicular crys- 

 tals, fl, Pitted wood fibers. /. Bast. PC, Cortical parenchyma, ph, Phelloderm. s, s', Cork, in 

 surface view and section, v, Pitted vessels. (From Greenish and Collin.) 



The trichomes furnish other valuable diagnostic characters, but they 

 are not always reliable, since Belladonna leaves that are almost glabrous, 

 and consequently almost devoid of trichomes, are sometimes found. 

 Either specimen may contain both simple and glandular hairs. The 

 simple hairs are conical and may be composed of one or more cells. In 

 Hyoscyamus the glandular heads, which may be either bicellular or multi- 

 cellular, pg, Fig. 280, are borne on a stalk composed of two or more cells. 

 The glandular hairs of Belladonna are found with heads either unicellular 

 or multicellular. The larger multicellular glands are usually borne on a 

 stalk consisting of one or two cells, pg, Fig. 279, while the smaller ones 



