172 
Lecithin. 
{Am.  Jour.  Pharm- 
April,  1914. 
phoric  acid  in  the  seeds  of 'millet  in  comparison  with  the  amount  of 
organic  phosphorus  present.  He  found  that  in  millet  lecithin  for- 
mation was  at  its  height  during  the  period  of  seed  development,  and 
that  the  maximum  amount  of  lecithin  was  contained  in  the  plant 
during  the  period  of  panicle  formation.  Thus  it  is  justifiable  to 
draw  the  conclusion  that  lecithin  has  important  functions  to  perform 
in  connection  with  flower  and  seed  formation. 
Hoppe-Seyler  pointed  out  the  close  relationship  between  lecithin 
and  chlorophyll  mentioned  above.  He  even  placed  chlorophyll  in 
the  group  of  lecithins.  Although  this  view  has  not  as  yet  been  con- 
firmed, it  is  supported  to  some  extent  by  Stoklasa's  researches. 
Furthermore,  Marchlewski,  Bode  and  Kohl  have  put  forward  theo- 
retical considerations  according  to  which  chlorophyll  represents  a 
lecithin  in  which  the  fatty  acid  radicles  6  are  replaced  by  special, 
colored  complexes  (chlorophyllanic  acids),  or  these  complexes 
themselves  are  chlorophyll  combined  with  lecithin.7 
Hanai's  statements  supplement  Stoklasa's  communications.  He 
made  the  observation  that  the  old,  green  leaves  of  Thea  Chinensis 
lose  their  lecithin  in  spring,  and  that  the  young,  growing  leaves  are 
very  rich  in  lecithin.  He  therefore  places  lecithin  among  the  re- 
serve substances,  which  are  stored  in  certain  parts  of  the  plant  (as, 
for  example,  in  the  bark  of  the  plant  just  mentioned)  until  the  next 
period  of  growth,  when  they  are  supplied  to  the  new  shoots.8 
The  conclusions  drawn  by  Vageler  from  his  investigations  are 
deserving  of  special  mention.  According  to  these,  the  lecithins  are 
inseparably  bound  up  with  metabolism  and  with  the  vital  processes 
of  the  plant  generally.  The  content  of  phosphatides  increases  up  to 
the  time  of  development  of  the  fruit,  the  zenith  of  development,  and 
decreases  as  the  fruit  ripens.    Lecithin  has,  in  the  author's  opinion, 
11  Compare  the  formula  for  lecithin  on  page  164. 
7  According  to  W.  Pfeffer  (Pflanzenphysiologie,  1897,  2nd  edition,  Vol. 
1.  p.  478).  the  lecithins  are  perhaps  necessary  for  the  construction  of  proto- 
plasts. However,  it  is  not  yet  known  whether  they  take  part  in  the  con- 
version of  fats.  The  occurrence  of  choline  in  plants  probably  depends  upon 
the  conversion  of  lecithin.  According  to  Willstatter,  chlorophyll  contains 
no  phosphorus,  whereby  the  theories  of  the  authors  mentioned  above  are  in- 
correct. Compare  also  Marchlewski,  Biochemische  Zeitschrift,  1908,  Vol. 
10,  p.  131. 
8  According  to  Jost  (Pflanzenphysiologie,  1908,  p.  184),  however,  the  leci- 
thins are  not  reserve  substances,  but  constructive  materials  for  protoplasm, 
and  for  this  reason  they  are  not  decomposed  during  germination  of  the  seeds. 
