RHIZOJIES AND ROOTS. 



249 



PLATE CIX. 



FIG. 119. Powdered Marshmallow Root (x 240). 



a, Starch grains. 



cm, Mucilage cells. 



cr, Crystals of calcium oxalate. 



f , Sclerenchyrnatous fibres from bast ring and wood. 



I, Bast. 



pc, p'c', Cortical parenchyma in longitudinal and transverse section. 



pi, Parenchyma of the wood in longitudinal section. 



rm, r'm', Medullary rays in longitudinal and tangential section. 



s, s', Cork in surface view and profile. 



tra, Pitted tracheids. 



v, vs, Vessels. 



