796 



BOTANY AND PHARMACOGNOSY. 



b. INSOLUBLE IN ALCOHOL. 



a Reddish Color With Sulphuric Acid After Souic Time. 

 257. SACCHARUM LACTIS. Small and large irregular- 

 shaped crystals insoluble in mounts of glycerin, or alcohol. 



mPoO o p o o 





o 



OOmO 



Fig. 321. Wheat grain {Triticum sativum): A, transverse section showing epicarp 

 (e), cells of mesocarp (m), tangentially elongated cells (querzellen) (t), tube cells (c), 

 spermoderm (s), perisperm (p), aleurone cells (a), parenchyma containing starch (st); 

 B, surface section of pericarp showing relation of epidermal cells (e) to tangentially elon- 

 gated cells (t); C, hair from the apex of the grain with thick wall and very narrow lumen; 

 D, apical portion of a hair; E, starch grains. 



Rye grain (Secale cereale): F, hair with wall comparatively thinner than in the hair 

 of the wheat grain; G, apical portion of a hair; H, tangentially elongated cells in which 

 the pores occur only on the tangential walls; I. starch grains which vary from 20 to 70 /i 

 in diameter, and occasionally have delicate clefts. 



Barley grain (Hordeum sativum): J, transverse section of palet (pa) and pericarp (pe), 

 aleurone layer (a) composed of two or three rows of cells, parenchyma of endosperm con- 

 taining starch fst); K, hair from epicarp with very thin wall and large lumen; L, tan- 

 gentially elongated cells which differ from those of wheat and rye in being without pores; 

 M, starch grains which resemble those of wheat but are uniformly smaller. 



