Am.  Jour.  Pharm. 
Aug  ,1886. 
Insects  and  Flowers. 
403 
in  the  sap  and  yellow  in  the  protoplasm,  found  together  in  scarlet 
flowers,  present  just  such  a  combination  to  our  eyes,  as  when  we  set 
a  red  glass  and  a  yellow  one  side  by  side,  we  see  before  us  a  mixture 
of  the  two  colors. 
By  diminishing  exposure  to  light,  a  complete  alteration  can  be 
produced  in  the  relative  amount  of  coloring  matter,  although  no  in- 
variable rule  can  be  laid  down  as  to  its  influence,  since  some  flowers 
retain  their  color  in  darkness,  whilst  others  lose  it.  Indeed,  it  has 
been  affirmed  that  flowers  produce  their  intensest  colors  in  the  dark, 
even  if  the  whole  plant  is  kept  in  the  dark,  but  in  such  cases  there 
can  be  no  production  of  chlorophyll  green.  It  may  be  mentioned 
that  chlorophyll  green  is  always  accompanied  by  chlorophyll  yellow, 
which  is  much  less  sensitive  to  light,  and  remains  after  the  disappear- 
ance of  the  green. 
It  is  well  known  that  the  soil  has  an  immense  influence  on  color, 
insomuch  that  many  variations  can  be  produced  at  will,  and  the  mere 
transplantation  of  a.  plant  will  alter  its  color.  Much  care  has  to  be 
taken  as  to  the  material  in  which  tulips  and  other  florist's  flowers  are 
grown,  since  if  they  should  be  too  highly  nourished  they  are  apt  to 
lose  their  distinctive  stripes,  to  which  they  owe  their  marketable 
value.  These  brilliant  stripes  are  due  to  bad  variation,  and  it  may 
be  noticed  incidentally  that  when  branches  become  variegated  by 
bad  variation,  and  the  variety  is  attempted  to  be  propagated  by  seed, 
the  seedlings  are  rarely  variegated.  But  variation  is  much  surer 
and  more  powerful  than  any  change  that  can  be  effected  by  the  cross- 
ing of  flowers.  Even  a  leaf  inserted  by  its  footstalk  into  the  bark 
of  the  stock  is  sufficient  to  communicate  variation  to  it,  although  the 
leaf  soon  perishes.  Garbner  relates  that  branches  of  white  and  dark- 
fruited  vines,  which  were  split  longitudinally,  and  then  joined,  pro- 
duced distinct  bunches  of  grapes  of  the  two  colors,  and  other  bunches 
with  berries  either  striped  or  of  an  intermediate  or  new  tint.  Dar- 
win alludes  to  this,  and  observes,  "These  facts  are  the  more  remark- 
able because  Andrew  Knight  never  succeeded  in  raising  variegated 
grapes  by  fertilizing  white  kinds  by  pollen  of  dark  kinds."  He 
also  draws  from  this  and  similar  cases  the  highly  important  physio- 
logical fact  that  the  elements  which  go  to  the  production  of  a  new 
being  are  not  necessarily  formed  by  the  male  and  female  organs. 
They  are  present  in  the  cellular  tissue  in  such  a  state  that  they  can 
unite  without  such  aid. 
