Am.  Jour.  Pharm. 
June,  1921. 
Plant  Colors. 
415 
4.  The  blue  anythocyanin  colors  may  separate  under  certain 
conditions  as  when  there  are  marked  changes  in  temperature  or  other 
disturbances  in  the  cell  in  the  form  of  either  spherical  globules, 
which  may  be  relatively  numerous  as  in  the  petals  of  Catalpa  or  in 
larger  globules  as  in  the  petals  of  Cinearia,  Delphinium  and  blue 
hydrangeas,  or  may  show  a  spherite  structure  or  separate  in  the  form 
of  long  rods  as  in  the  leaves  of  red  cabbage. 
5.  The  red  anthocyanin  colors  are  of  two  kinds : 
a.  Those  which  change  to  a  blue  or  purplish  red  as  in  the 
rose,  mertensia,  tiger  lily,  tulip,  cineraria,  dogwood, 
red  hydrangea,  and  red  cabbage. 
b.  Second  class  includes  those  red  anthocyanins  which  do 
not  change  in  color  as  in  red  apples  and  in  nearly  all 
of  the  red  fruits. 
6.  Anthocyanin  colors  may  also  occur  in  the  same  cells  which 
contain  either  chloroplastids  or  chromoplastids.  As  examples  in 
which  both  chloroplastids  and  anthyocyanins  occur  in  the  same  cell 
may  be  mentioned  the  leaves  of  wild  carrot,  the  beet,  and  purple 
beech.  Chromoplastids  and  anthocyanin  colors  are  frequently  to  be 
found  in  flowers  as  the  nasturtium  and  tiger  lily. 
7.  Anthocyanin  colors  while  found  in  the  stems  and  leaves,  and 
also  in  thorns  as  in  roses  are  usually  more  pronounced  or  more 
strongly  developed  in  those  organs  at  the  extremity  of  the  plant  or 
at  the  tips  or  shoots  as  in  the  purple  beech  and  in  flowers  generally. 
8.  Plant  color  substances  from  their  solubility  may  be  grouped 
into  two  classes : 
a.  Those  while  like  the  plastid  color  substances  are  insoluble 
in  water  and  soluble  in  immiscible  solvents  as  petro- 
leum benzine,  toluol,  ether,  etc. 
b.  Those  which  are  soluble  in  water  or  at  least  in  hydro- 
alcoholic  solutions,  but  insoluble  in  the  immiscible  sol- 
vents. 
9.  The  investigations  of  plant  color  substances  show  that  they 
may  be  brought  into  probably  three  groups : 
a.  Colorless,  or  leuco-compounds,  which  upon  oxidation 
form  distinct  color  substances  as  in  the  lichens. 
