200  Structure  of  Veratrum  Viride.  {AmI$rii,im*m' 
in  a  longitudinal  direction,  into  two  or  more  wedge-shaped  or  flat 
pieces.  The  fracture  is  short,  and  the  color,  internally,  whitish. 
The  cross-section  shows  a  distinct  cylinder  sheath  forming  an  irreg- 
ular dark  line  between  the  central  cylinder  and  the  thickish  cortex. 
The  bundles  are  of  the  concentric  type,  with  a  small  central  phloem 
surrounded  by  two  or  three  "layers  of  small  sized  scalariform  ducts 
and  tracheids,  and  these  are  bounded  exteriorly  by  an  endodermis. 
Fig.  4. 
The  ducts  and  tracheids  are  irregular  in  form  and  direction  in  the 
bundle.  The  bundles  also  pursue  a  very  irregular  course  in  the 
rhizome,  so  that  a  cross-section  cuts  some  of  them  transversely, 
others  longitudinally,  and  still  others  obliquely,  giving  rise  to  the 
appearance  of  numerous  irregular  brownish  dots  and  wavy  lines, 
imbedded  in  the  whitish  parenchyma.  In  the  cortex,  the  wavy 
lines  and  dots  are  also  present,  but  less  numerous,  and  toward  the 
outside  are  seen  the  sections  of  the  root-bundles  near  their  origin. 
