510  Medicinal  Plant  Gardens.  {^ovembe/SoiT' 
nary  cultivated  crops.  I  am  convinced  that  in  some  cases  optimism 
and  enthusiasm  have  been  allowed  to  outrun  common  sense,  but  if, 
in  the  future,  due  consideration  is  given  to  the  fundamental  prin- 
ciples of  agricultural  economics,  I  believe  that  a  rational  attitude 
toward  commercial  drug-plant  cultivation  may  be  developed. 
The  founders  of  the  several  excellent  pedagogic  gardens  which 
are  now  maintained  in  connection  with  certain  schools  oi  pharmacy 
have  inaugurated  a  movement  which  promises  much  for  the  future 
of  Materia  Medica  and  Pharmacognosy.  It  is  sincerely  to  be  hoped 
that  their  example  will  lead  to  the  establishment  of  such  gardens  in 
connection  with  each  of  the  75  or  more  schools  of  pharmacy  in  the 
United  States,  and  to  an  extension  of  the  scientific  study  of  medicinal 
plants.  The  problems  demanding  attention  are  very  numerous,  but 
some  of  the  lines  of  study  and  investigation  which  need  to  be  empha- 
sized are  those  concerning  the  adaptation  and  acclimatization  of 
medicinal  plants,  the  conditions  under  which  the  active  principles  of 
plants  are  formed,  and  the  behavior  of  the  plants  themselves  under 
varying  conditions  of  climate  and  culture.  Moreover,  the  selection 
and  breeding  of  medicinal  plants  not  only  promises  to  yield  results 
of  great  practical  importance,  but  also  affords  a  field  for  the  widest 
scientific  activity. 
It  is  to  be  regretted  that  at  present  there  is  no  satisfactory  way 
in  which  the  investigations  being  made  upon  medicinal  plants  in 
different  sections  of  this  country  can  be  properly  correlated  and 
reduced  to  form  for  definite  comparison.  Especially  desirable  is  a 
practical  basis  of  correlation  for  studies  of  the  variation  in  plant 
constituents,  due  in  part,  at  least,  to  differences  in  geographical 
location.  When  two  more  or  less  widely  separated  workers  attempt 
to  compare  the  results  of  their  studies,  it  frequently  happens  that 
they  experience  the  greatest  difficulty  in  harmonizing  their  results. 
This  is  due  in  part  to*  differences  in  the  response  which  plants  make 
when  under  different  environmental  conditions,  in  part,  probably, 
to  variations  in  the  method  of  procedure  followed  in  the  cultivation, 
curing,  and  analysis  of  the  plant,  and  in  part,  no  doubt,  to  differ- 
ences in  the  genetic  relationship  of  the  plants  studied  by  the  respec- 
tive investigators. 
There  seems  to'  be  an  opportunity  for  some  arrangement  or  mutual 
agreement  between  the  representatives  of  our  various  medicinal 
plant  gardens  under  the  terms  of  which  multiplicate  samples  of  seeds 
