POWDERED DRUGS AND FOODS. 771 



tinguished by the epidermal cells with peculiar diagonal thick- 

 ening of the walls and the hypodermal fibers which have thick, 

 porous walls and brown contents. (See also under Pimenta, 

 No. 113.) 



159. COLCHICI SEMEN.— Light or dark brown; scleren- 

 chymatous cells with. pigment soluble in potassium hydrate solu- 

 tion, and reacting with iron salts somewhat like tannin ; cells of 

 endosperm thick-walled, with simple pores and few oil globules ; 

 parenchymatous cells of strophiole thin-walled, and with numer- 

 ous nearly spherical starch grains 7 to 15 /* in diameter. 



tt Not Becoming Blue or Green with Ferric Salts. 



160. ACONITUM. — Dark brown (Figs. 206, 309) ; tracheae 

 few, spiral, scalarif orm, reticulate, or with simple pores ; stone cells 

 nearly isodiametric, variously thickened, associated with thick- 

 walled parenchyma, the latter swelling in water; starch grains 

 somewhat spherical, 4 to 12 /x in diameter, single or 2- to 4- 

 compound. 



161. PHYSOSTIGMA.— Brownish-black ; taste starchy; 

 stone cells nearly isodiametric or elongated, the contents red- 

 dened by alkalies ; starch grains ellipsoidal, about 25 to 40 /j. in 

 diameter ; oil globules numerous. 



** Stone Cells Wanting. 



162. COLCHICI CORMUS.— Light or dark brown; starch 

 grains irregularly spherical or ovoid, 7 to 20 /n in diameter, single 

 or 2- to 4-compound; tracheae few, spiral or scalarif orm (Fig. 

 310). 



163. GUARANA.— (See No. 157.) 



164. MYRISTICA. — Light brown; perisperm cells with red- 

 dish contents ; starch grains somewhat spherical, 5 to 7 /* in diam- 

 eter, generally in groups; globules of fixed oil numerous. 



165. MACIS. — Amylodextrin starch grains (Fig. 190) which 

 , are colored red with iodine. For other characteristics of gen- 

 uine mace and the study of allied products and substitutes see 



P- 443- 



166. OPIUM.— (See No. 197.) 



