Fig.  2. — Longitudinal  section  of  Cotton  Root  Bark.  (c)  cork  cells  ;  (/>) 
parenchyma  ;  (b)  bast  fibres  ;  (S.  J?.)  secretion  reservoirs  ;  {in )  medullary  rays  ; 
{t)  cells  containing  tannin  ;  (cr)  crystals  of  calcium  oxalate. 
