434 SCIENTIFIC AND APPLIED PHARMACOGNOSY 



FIG. 190. Longitudinal section of cotton root bark: C, cork cells; P, paren- 

 chyma; B, bast fibers; SR, secretory cavities, having a brownish, amor- 

 phous content; M, medullary rays; T, cells containing tannin; K, rosette 

 aggregates of calcium oxalate from 0.010 to 0.025 mm. in diameter. After 

 Morgan. 



