754 



BOTANY AND PHARMACOGNOSY. 



cells occurring beneath the cork cells, 40 to 125 /x in diameter, 

 with walls that are somewhat lamellated, 15 to 20 fi thick and 

 with few simple pores ; cork cells light brown ; sclerenchymatic 

 fibers wanting; tracheae about 100 /x wide, with scalariform and 

 reticulate thickenings of the wall. On mixing the powder with 

 water and adding a solution of one of the alkalies a red color 

 is produced. In Riimcx hymcnoscpahis the parenchyma cells are 

 about 200 fx. in diameter, with reddish colored walls and contain 

 numerous spherical or ellipsoidal starch grains from 8 to 15 /x 

 in diameter ; calcium oxalate crystals are few or wanting. 



C 



Fig. 301. Several forms of stone cells. A, white oak bark; B, white cinnamon or 

 canella bark (Canella alba) ; C, seed-coat of capsicum. 



iioa. CANELLA (White Cinnamon). Light brown or light 

 reddish-brown ; calcium oxalate in rosette aggregates, from 

 20 to 50 yu, in diameter ; starch grains simple or 2- to 3-com- 

 pound, 5 to 10 /x in diameter; numerous stone cells, about 75 /x in 

 diameter, the inner walls of which are considerably thickened, 

 and with branching pores ; sclerenchymatic fibers occasionally 

 present; numerous large oil cells with suberized walls (Fig. 

 301, B). 



** No Resin or Tannin Masses. 



III. ALTH^A. Light brown (Fig. 99, B) ; sclerenchyma 

 fibers long and not strongly lignified ; rosette aggregates of cal- 

 cium oxalate, about 25 fi in diameter; starch grains somewhat 

 ellipsoidal, 10 to 20 /x in diameter. 



