454 



BOTANY AND PHARMACOGNOSY. 



Fio. 196. Peravian rhatany: A, transverse section showing cork (k), a group ot 

 6ast fibers (sk), parenchyma of cortex (p), one cell near the middle containing a mono- 

 clinic p>rism of calcium oxalate (o), medullary-ray cells of bark (m), cambium (c), tracheae 

 (t), wood fibers (sc), wood parenchyma (hp), medullary-ray cells (m); B, bast fiber; C, 

 wood fiber with neighboring parenchyma cells which are somewhat elongated and have 

 somewhat thickened, porous walls; D. trachea. After Meyer. 



