io6    Migration  of  Plants  from  Europe  to  America,  {^"^y^S^'J^o''''' 
homely  weeds  of  England  and  France  made  themselves  at  home  in  the  New  World  y 
established  themselves  on  its  soil,  appropriated  its  fields,  its  gardens  and  its  waysides. 
Nor  have  the  older  States  alone  been  seized  by  these  European  invaders.  The 
stream  has  flowed  beyond  them,  and  as  no  village  or  hamlet  in  the  West  is  without 
its  population  of  European  descent,  so  too  it  is  never  without  its  plant  population  of 
European  weeds.  To  the  American,  born  and  reared  among  them,  these  things 
have  none  of  the  significance  which  they  possess  to  him  who  comes  across  the 
Atlantic,  conversant  with  the  flora  of  Europe,  and  anticipating  a  complete  change 
of  plant  life  as  well  as  of  place  and  scene  after  voyaging  3,000  miles.  And  yet  I 
scarcely  know  which  strikes  the  thoughtful  stranger  most,  the  resemblance  or  the 
difference  between  the  Old  which  he  has  left  or  the  New  to  which  he  has  come. 
Differences,  of  course,  there  are,  many  and  great,  but  in  the  face  of  the  fact  that 
the  new  country  with  its  millions  of  inhabitants  is  using  the  same  language  and  laws 
and  customs  as  the  old  country  he  has  so  lately  left,  they  are  less  striking.  The 
same  is  true  of  the  American  flora.  The  writer  will  never  forget  the  impression 
made  on  his  own  mind  when  soon  after  landing  in  America  he  set  to  work  upon  the 
botany  of  his  new  home.  The  summer,  with  its  floral  treasures,  had  gone  by  and 
the  brilliant  New  England  foliage  told  that  winter  was  rapidly  approaching.  In  the 
woods  and  shrubberies  th'e  falling  leaves  revealed  new  types  of  tree-life  mingled  with 
old  forms  well  known  in  England.  But  on  the  ground,  in  the  fields,  along  the  way- 
sides and  fences  were  many  well-known  plants.  Old  acquaintances,  friends  and  foes 
both,  which  he  had  years  before  learned  to  know — sometimes  to  cherish  and  often 
to  uproot — when  a  boy  in  the  old  country.  So  far  was  the  flora  from  being  totally 
new  that  sometimes  he  was  puzzled  to  know  whether,  on  a  given  space,  there  were 
more  strange  or  familiar  forms  around  him.  This  result  was  quite  unexpected  and 
opened  before  him  a  new  and  very  interesting  field  of  observation  and  investigation, 
which  has  continued  ever  since  to  occupy  at  intervals  his  attention.  The  fact  here 
mentioned — this  migration  of  European  plants  into  America — became  all  the  more 
striking  when,  after  a  longer  residence  in  this  country,  and  a  further  study  of  its 
flora,  he  looked  back  to  his  earlier  botanical  studies  in  Europe  and  observed  that 
this  vegetable  migration  is  almost  entirely  in  one  direction.  In  the  midst  of  this 
rich  flora,  aliens  by  origin,  but  naturalized  by  the  letters  patent  of  time,  he  looked 
back  to  his  old  home  and  tried,  but  almost  in  vain,  to  recall  American  forms  of 
plant  life  naturalized  there.  Scarcely  a  solitary  specimen  could  be  found  to  which 
the  Old  World,  always  chary  of  conferring  its  citinzenship  upon  foreigners,  could 
be  said  to  have  given  the  rights  to  home.  Whence  comes  this  striking  difference  ? 
Why  is  the  Western  World  so  hospitable  and  the  Eastern  so  inhospitable  to  vege- 
table strangers  ?  Is  it  that  these  western  strangers  do  not  claim  naturalization  ?  Da 
they  feel  their  inability  to'make  way  against  the  crowded  life  of  the  East,  and,  there- 
fore, fail  in  the  intenser  struggle  for  existence  which  marks  newer  and  more  highly 
developed  Europe?  The  full  answer  to  this  question  is  at  present  impossible,  and 
the  writer  desires  this  paper  to  be  considered  merely  suggestive.  Facts  must  be 
gathered  before  "conclusions  can  be  drawn.  The  field  is  so  vast  and  the  need  of 
patient  and  continuous  observation  so  great  that  many  years  may  pass  ere  a  solution 
