ArjkiuarVfiw4.m }        Gardens  of  Medicinal  Plants.  29 
stitutes  of  medicinal  plants ;  plants  having  no  medicinal  value  but 
used  in  medical  and  pharmaceutical  practice.  Enough  of  each 
species  should  be  grown  to  supply  the  requirements  of  the  various 
gardens. 
V.   GROUPING  OF  PLANTS. 
This  is  a  matter  of  greater  importance  than  would  appear  on  first 
consideration.  A  grouping  according  to  natural  orders  or  accord- 
ing to  physiological  action  or  constituents  is  not  natural,  and  to 
make  such  grouping  in  a  measure  successful,  entails  extra  labor  and 
expense  and  the  scheme  cannot  be  carried  out  consistently  or  com- 
pletely in  many  instances.  A  more  rational  plan  would  be  to  group 
them  ecologically,  that  is,  according  to  the  natural  requirements  and 
conditions  of  soil,  light,  moisture  and  temperature.  According  to 
such  a  plan,  the  following  would  be  a  brief  tentative  outline  of  the 
groups : 
Group  I. — Trees  and  woody  climbers  (as  grape,  ivy,  poison  ivy), 
including  those  herbs  and  shrubs  which  require  shade  (forest  and 
woodland  shrubs  and  herbs). 
Group  II. — Shrubs ;  beginning  with  the  larger  tree-like  forms 
(dogwood,  spiraea,  etc.),  grading  off  with  smaller  shrubs  (black- 
berries, etc.). 
Group  III. — Herbaceous  plants  and  small  shrubby  plants  which 
do  not  require  shade.  These  may  again  be  separated  into  sub- 
groups according  to  nature  of  soil,  water  required,  climbing  herbs, 
runners,  smaller  herbs  and  large  succulent  herbs,  etc.  This  group 
would  consist  largely  of  annuals  and  biennials  and  is  the  largest  and 
most  important  group. 
Group  IV. — Water  plants,  that  is,  such  as  are  wholly  or  partially 
snbmerged  below  the  surface  of  the  water.  These  are  to  be  grown 
in  artificial  ponds  when  necessary. 
Group  V.- — Bog  or  marsh  plants,  such  as  require  very  wet  soil. 
These  tor  the  most  part  also  require  more  or  less  shading. 
Group  VI. — Xerophytic  or  dry-soil  plants.  They  require  com- 
paratively dry  sandy  soil  with  good  drainage  and  plenty  of  sunlight. 
They  are  mostly  of  tropical  or  sub-tropical  origin,  and  must  be 
grown  in  well-protected  areas  or  in  hothouses. 
Group  VII — Tropical  plants.  These  must  for  the  greater  part 
be  grown  in  hothouses. 
It  is  hoped  that  these  suggestions  may  be  of  some  practical  ben- 
