Am.  Jour.  Pharm.  ) 
April,  1914.  J 
Lecithin. 
171 
in  the  form  of  organic  compounds.  Besides  the  nuclein  compounds, 
lecithin  is  an  important  example  of  this  class.  It  probably  plays  an 
important  part  in  the  processes  of  assimilation  and  dissimilation. 
In  testing  the  lecithin  content  of  seedlings,  leaves  and  blossoms,  the 
author  found  that  the  lecithin  was  not  decomposed  by  germination, 
but  that  no  lecithin  was  formed  except  when,  under  the  influ- 
ence of  light  and  chlorophyll,  carbonic  acid  assimilation  had  set  in. 
He  even  showed  that  in  the  absence  of  chlorophyll  (in  the  leaves) 
no  lecithin  is  formed  and  that  in  etiolated  seedlings  the  lecithin  is 
used  up  or  decomposed.  It  is  possible  that  during  the  first  vegeta- 
tive period  lecithin,  under  the  influence  of  light,  assists  in  the  for- 
mation of  chlorophyll  in  the  seedling.  The  greatest  amount  of 
lecithin  is  probably  formed  in  fresh  green  leaves  at  the  time  when 
the  function  of  assimilation  is  at  its  height,  an  assumption  made 
probable  by  the  fact  that  the  amount  of  lecithin  in  leaf-buds  is  only 
half  as  great  as  that  in  fully  developed  leaves,  and  that  it  rapidly 
disappears  as  the  leaves  grow  older;  the  chlorophyll  is  reduced  and 
xanthophyll  makes  its  appearance.  According  to  this,  there  is  a 
close  connection  between  the  formation  of  chlorophyll  and  lecithin. 
Stoklasa  even  considers  that  lecithin  may  be  a  product  of  assimila- 
tion in  the  chlorophyll  corpuscle  itself.  In  agreement  with  this 
conjecture  is  the  observation  that  certain  plants,  if  placed  in  the 
dark  at  the  time  of  their  most  active  growth,  soon  show  a  consid- 
erable diminution  of  lecithin  in  their  leaves,  as  compared  with  those 
which  are  allowed  to  develop  in  the  light.  It  has  not  yet  been  dis- 
covered in  what  way  lecithin  assists  in  chlorophyll  formation,  but 
according  to  Stoklasa,  it  is  certain  that  no  chlorophyll  can  be  pro- 
duced in  the  absence  of  light  and  phosphorus.  Thus' even  if  lecithin 
is  not  a  part  of  the  chlorophyll  corpuscle  itself,  as  was  formerly 
assumed  by  Marchlewski,  yet  it  appears  to  participate  in  chlorophyll 
formation  and  to  supply  the  necessary  phosphorus.  From  the 
leaves  lecithin  travels  by  way  of  the  stems  into  the  blossoms,  where 
it  may  perhaps  assist  in  fertilisation,  and  thence  by  the  fruits  into 
the  seeds.  It  is  by  no  means  certain,  however,  that  the  green  leaves 
are  the  sole  producers  of  lecithin ;  it  is  quite  probable  that  plants 
and  animals  are  able  to  build  up  lecithin  in  certain  organs  and  from 
certain  substances,  as  is  the  case  for  example  in  yeast  and  in  fungi. 
Stoklasa' s  observation  that  phosphorus  is  present  in  plants  chiefly 
in  organic  form  is  confirmed  by  the  results  of  Staniski's  researches. 
This  observer  found  only  very  small  amounts  of  inorganic  phos- 
