414 
Plant  Colors. 
5  Am.  Jour.  Pharm. 
I      June,  1921. 
of  glims  not  previously  precipitated.  These  gums  could  possibly  have 
been  weighed  finally  as  glycyrrhizic  acid.  The  filtrate  is  then  to  be 
evaporated  to  a  syrup,  and  transferred  with  30  cc.  water  to  a  thin- 
walled  glass  cylinder.    I  used  a  wide  test  tube  for  this  purpose. 
[Translator's  Note. — Linz  goes  on  to  show  that  the  proposal 
of  Evans  to  obtain  the  glycyrrhizin  sticking  to  the  bottom  of  the  ves- 
sel by  freezing  and  subsequent  thawing  is  a  good  idea,  but  unfortun- 
ately does  not  work  out  in  practice  as  described.  Linz  tried  it  six 
times  unsuccessfully.    (P.  A.  H.)] 
(To  be  Continued.) 
PLANT  COLORS 
By  Dr.  Henry  Kraemer,  Mt.  Clemens,  Mich. 
The  nature  of  plant  color  has  been  the  subject  of  some  investi- 
gation and  considerable  speculation.  There  is  no  objection  to  con- 
structing theories  concerning  the  origin,  nature  and  functions  of 
plant  colors,  providing  we  recognize  that  they  are  apt  to  be,  with  our 
meager  knowledge  of  plant  color  substances,  mere  speculations,  and 
it  is  doubtful  if  any  of  our  theories  will  stand  the  test  of  time  as  new 
investigations  are  made.  There  are  probably  a  few  facts  that  we 
recognize,  and  some  of  these  may  be  briefly  stated  as  follows : 
1.  The  name  anthocyanin  as  first  given  by  Marquardt  may  be 
used  to  designate  all  the  plant  colors,  other  than  the  green  and  yel- 
low which  are  plastid  colors.  The  anthocyanin  colors  usually  occur 
in  the  cell  sap  and  may  be  present  in  flowers  fruits,  roots  and  leaves 
of  higher  plants,  or  even  in  the  lower  plants. 
2.  In  the  marine  algae  the  anthocyanin  colors  seem  to  be  con- 
tained in  plastids  and  are  usually  not  liberated  and  distributed  free 
in  the  cell  until  the  death  of  the  filament.  In  the  higher  plants  the 
anthocyanin  colors  are  usually  present  in  the  vacuoles  of  the  cell  and 
are  usually  of  either  a  blue  or  red  color,  but  many  intervening  shades 
of  red  and  blue  are  to  be  seen. 
3.  The  blue  anthocyanin  are  variously  distinguished,  some  being 
quite  permanent  as  in  the  flowers  of  Delphinum,  Viola  and  Malva, 
even  on  the  death  of  the  cell  or  drying  of  the  plant,  whereas  in  other 
plants  they  are  decomposed,  changing  to  a  fawn  or  brown  color,  as  in 
the  flowers  of  Pawlonia,  Bellis,  etc. 
