294  The  Pharmacognosy  of  Helonias.    { AmjJ°uri9^7arm* 
more  numerous  in  the  newer  growth  near  the  crown  and  are  often 
decayed  in  the  older  parts  of  the  rhizome.  The  lower  portion  of 
the  rhizome,  representing  growth  two  or  more  years  old,  often  de- 
cays and  disappears  causing  the  rhizome  to  end  abruptly.  The 
color  varies  from  light  brown  to  yellowish ;  fracture  of  the  rhizome 
tough  and  horny ;  odor  slight ;  taste  bitter. 
I 
Fig.  4.  Radial-longitudinal  section  of  the  central  portion  of  Helonias 
rhizome.  A,  entering  root,  showing  manner  in  which  the  root  divides  just 
inside  the  pericycle,  and  connects  with  the  vascular  system  of  the  rhizome.  B, 
endodermal  layer ;  C,  cortex ;  D,  central  cylinder. 
Helonias  rhizome  presents  a  most  interesting  structure,  and 
is  a  fine  illustration  of  the  fact  that  nature  refuses  to  follow  man- 
made  laws.  Fig.  2,  a  transverse  section  through  the  central  portion 
of  a  seedling  rhizome,  shows  the  foramina  spoken  of  by  Millspaugh, 
cut  obliquely.  They  may  appear  in  any  portion  of  the  cortex,  and 
as  will  be  later  shown,  vary  in  size  and  appearance  according  to 
