l8  SMITHSONIAN    MISCELLANEOUS    COLLECTIONS  VOL.    96 
It  would  appear  that  growth  of  the  coleoptile  retards  the  growth 
of  the  first  internode  and  that  the  growth  of  the  one  tissue  takes 
place  at  the  expense  of  the  other.  Light  probably  acts  more  as  a 
redistributing  agent  of  the  growth  substances  than  an  inactivating 
agent.  However,  even  at  the  low  intensities  here  employed,  there 
was  a  slight  indication  that  some  inactivation  occurred,  since  the 
average  total  length  of  the  illuminated  seedlings  was  slightly  less 
than  that  of  the  dark  controls. 
LITERATURE  CITED 
Avery,  George  S.,  Jr. 
1930.  Comparative  anatomy  and  morphology  of  embryos  and  seedlings  of 
maize,  oats,  and  wheat.    Bot.  Gaz.,  vol.  9,  no.  i,  pp.  1-39. 
Boysen-Jensen,  p. 
1936.  Growth  hormones  in  plants.   English  translation  and  revision  by  G.  S. 
Avery,  Jr.,  and  P.  R.  Burkholder.   268  pp.    New  York. 
Du  Buy,  H.  G. 
1933-    t)ber  Wachstum  und  Phototropismus  von  Avcna  saliva.    Rec.  Trav. 
Bot.  Neerlandais,  vol.  30,  pp.  798-925. 
Du  Buy,  H.  G.,  and  Nuernbergk,  E. 
1934.    Phototropismus  und  Wachstum  der  Pflanzen.    Ergebn.  Biol.,  vol.   10, 
pp.  207-322. 
1935-    Phototropismus  und  Wachstum  der  Pflanzen.    Ergebn.  Biol.,  vol.  12, 
pp.  325-543. 
Flint,  Lewis  H.,  and  McAlister,  E.  D. 
1935-  Wave  lengths  of  radiation  in  the  visible  spectrum  inhibiting  the  germi- 
nation of  light-sensitive  lettuce  seed.  Smithsonian  Misc.  Coll., 
vol.  94,  no.  5,  pp.  i-ii. 
1937.  Wave   lengths   of   radiation   in   the    visible   spectrum    promoting   the 
germination  of  light-sensitive  lettuce  seed.    Smithsonian  Misc.  Coll., 
vol.  96,  no.  2,  pp.  1-8. 
GoRTER,  C.  J.,  and  Funke,  G.  L. 
1937-    Wachstum  und  Wuchsstoffproduktion  bei  Keimpflanzen  von  Raphamis 
sativus  in  trockener  und  fluchten  Luft.    Planta ;  Archiv.  wiss.  Bot., 
vol.  26,  no.  4,  pp.  532-545. 
IIamada,  H. 
1931.  tJijer    die    Beeinflussung    des    Wachstums    des    Mesokotyls    und    der 
Koleoptile  von  Aveiia-Ke\m\mgen  durch  das  Licht.    Mem.  Coll.  Sci. 
Kyoto  Imp.  Univ.,  ser.  B,  vol.  6,  pp.  161-238. 
Johnston,  Earl  S. 
1934.  Phototropic  sensitivity  in  relation  to  wave  length.  Smithsonian  Misc. 
Coll.,  vol.  92,  no.  II,  pp.  I -17. 
Norem,  W.  Luther. 
1936.  Mineral  nutrition  and  seasonal  growth  of  ageratum  in  sand  cultures 
with  auto-irrigation.   Amer.  Journ.  Bot.,  vol.  23,  pp.  545-555. 
