RHI OMES AND EOOTS. 



223 



PLATE XCVL 



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FIG. 106. Powdered Calumba Root (x 240). 



a, Starch grains. 

 cr, Calcium oxalate crystals. 

 , I', Bast in longitudinal and transverse section. 

 m, Parenchyma of wood. 



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

 rm. Medullary ray. 



s, s', Cork, in surface view and transverse section. 

 sc, Sclerenchymatous cells. 

 v, tr, Vessels, tracheids, etc. 



