386  Structural  Plant  Relationships.        { Amii°gulu mfm' 
agents  of  the  past,  and  their  qualities  at  present,  will  deny  the 
supremacy  of  vegetable  structures  as  corrective  agents  in  the  hands 
of  men  qualified  to  use  them  intelligently. 
The  life  of  man  and  the  health  of  man  depend  on  the  conservation 
of  energy  held  in  the  life  forces  that  are  locked  in  vegetable  struc- 
tures, be  they  called  food  or  remedy.1 
Empiricism  in  Food  and  Remedy  Studies. — As  the  natural  foods  of 
man  are  empirical  (established  by  experimentation)  so  are  the  most 
useful  plant  remedies  the  result  of  empiricism.  Lost  in  the  past  are 
the  experiments  that  led  man  to  know  that  wheat  is  a  food,  and  the 
same  is  true  of  most  fruits.  The  wanderings  which  give  us  our 
known  foods  and  medicines  are  not  less  tortuous  than  the  painful 
creeping  of  the  human  family  from  out  savagery  into  civilization. 
But  they  are  more  obscure,  because  in  the  main  the  journey  com- 
menced before  man  presumed  to  record  any  data  whatever.  It 
antedated  the  records  of  lost  civilizations,  and  came  down  much  after 
the  manner  in  which  a  robin  teaches  its  young  to  eat  a  worm.  Who 
can  tell  the  number  of  lives  lost  in  the  experimentation  that  finally 
led  to  the  separating  of  the  poison  that  exists  in  the  tapioca  plant 
from  the  wholesome  starch  food  known  as  tapioca  ?  Who  knows 
the  number  of  deaths  preliminary  to  man's  differentiating  between 
the  poisonous  and  the  edible  fungi,  which  is  yet  a  problem,  for  in 
this  field  deaths  often  occur  ?  The  story  of  how  the  acrid  arums 
came  to  be  utilized  by  primitive  people  so  as  to  become  foods,  or  of 
the  discovery  of  the  distinction  between  the  edible  fish  and  flesh 
and  forms  of  flesh  and  fish  unwholesome,  is  as  obscure  as  the  experi- 
ments that  led  to  the  utilization  of  innocuous  weeds  as  foods.  Some- 
where in  Nature's  climes  all  food  plants  are,  or  once  were,  weeds. 
To  find  their  value  as  nutrients  demands  experiment  which  estab- 
lishes some  as  useful  when  they  become  known  as  foods.  So  recent 
comparatively,  is  the  sad  proving  of  the  attempt  to  eat  as  a  pot  herb 
one  of  America's  new  plants,  as  to  have  fixed  the  term  Jamestozvn 
Weed  to  the  plant  which  the  settlers  of  Virginia  about  Jamestown 
investigated  to  their  sorrow  and  death.    Man's  search  for  food  is  a 
1  Do  not  infer  that  the  author  overlooks  or  condemns  animal  foods.  This 
paper  will  not  permit  a  consideration  of  that  phase,  but  it  may  be  briefly  said 
that  the  use  of  animal  food  is  but  the  utilizing  of  vital  force  that  has  been 
transferred  to  flesh  from  plants  that  the  animal  has  eaten.  Plant  life  is  the 
great  food  storehouse  of  both  carnivorous  and  herbivorous  animals. 
