A^'cXrrjKm*}  London  Botanic  Gardens.  453 
the  sequence  of  natural  orders  which  has  been  followed,  for  the 
herbaceous  plants  that  are  arranged  systematically,  is  that  of  Bent- 
ham  and  Hooker's  "  Genera  Plantarum." 
At  Kew  the  arrangement  adopted  by  Aiton  was  that  of  Linne,  to 
be  succeeded,  as  at  Chelsea,  by  that  of  Decandolle,  and,  subsequent- 
ly, during  Sir  J.  D.  Hooker's  directorate,  by  that  of  Bentham  and 
Hooker.  It  must  be  borne  in  mind  that  these  changes  could  only 
be  effectually  accomplished  with  herbaceous  plants,  and  that  matters 
are  complicated  at  Kew  by  the  fact  that,  in  addition  to  the  plants 
which  are  arranged  systematically,  there  are  many  others  scattered 
about  for  artistic  effect.  In  the  present  Arboretum,  commenced  in 
1845  by  Sir  William  Hooker,  and  remodelled  by  his  son,  an  arrange- 
ment in  regular  sequence  of  natural  orders,  such  as  that  adopted  for 
herbaceous  plants,  is  not  possible,  but  the  Conifem  are  grouped 
together  to  form  a  Pinetum,  and  most  of  the  Amentiferoe  are  also  in 
close  proximity  to  each  other.  In  the  collection  of  shrubs,  or  Fru- 
ticetum,  the  genera  of  the  same  natural  order  are,  as  a  rule,  grouped 
together.  Beyond  this,  little  attempt  is  made  at  systematic  arrange- 
ment. In  the  possession  of  an  extensive  Arboretum,  arranged  sys- 
tematically, so  far  as  possible,  Kew  differs  from  the  other  two 
Botanic  Gardens  in  London. 
The  herbaceous  collection  at  the  Regent's  Park  Gardens  was  ar- 
ranged according  to  natural  orders  from  the  first,  and  this  system 
has  subsisted  to  the  present  time,  with  slight  modifications.  The 
plants,  instead  of  being  set  out  in  parallel  beds  and  arranged  in  regu- 
lar sequence,  as  at  Kew  and  Chelsea,  are  disposed  in  beds  of  various 
shapes  and  sizes ;  each  bed  accommodates  one  natural  order,  and 
these  are  grouped  around  one  another  according  to  their  affinities. 
When  the  gardens  at  Chelsea  and  Kew  were  started,  medicinal 
plants  were  the  predominant  feature,  and  subsequently,  special  col- 
lections of  medicinal  plants  were  formed  in  both  of  them.  A  sec- 
tion for  economic  plants  was  also  set  aside  at  Regent's  Park,  but, 
with  the  exception  of  a  small  garden  of  hardy  herbaceous  medicinal 
plants  at  Kew,  and  of  a  belt  of  shrubs  and  trees  formerly  surround- 
ing the  herbaceous  ground  of  the  economic  collection  at  Regent's 
Park,  these  have  now  been  merged  into  the  general  herbaceous  col- 
lections;  and  even  in  the  case  of  Kew,  by  far  the  larger  number  of 
medicinal  plants  are  to  be  found  in  the  general  collection. 
In  addition  to  the  collections  already  enumerated,  it  is  to  be  noted 
